0aa1191c78
I would prefer to change RecordSet interface to return slice of values, rather than slice of pointers. But change an interface involve too many changes.
956 lines
29 KiB
Go
956 lines
29 KiB
Go
// Copyright 2015 PingCAP, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package plan
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import (
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"fmt"
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"github.com/juju/errors"
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"github.com/pingcap/tidb/ast"
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"github.com/pingcap/tidb/context"
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"github.com/pingcap/tidb/infoschema"
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"github.com/pingcap/tidb/model"
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"github.com/pingcap/tidb/mysql"
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"github.com/pingcap/tidb/sessionctx/db"
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"github.com/pingcap/tidb/sessionctx/variable"
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"github.com/pingcap/tidb/table"
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"github.com/pingcap/tidb/util/types"
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)
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// ResolveName resolves table name and column name.
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// It generates ResultFields for ResultSetNode and resolves ColumnNameExpr to a ResultField.
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func ResolveName(node ast.Node, info infoschema.InfoSchema, ctx context.Context) error {
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defaultSchema := db.GetCurrentSchema(ctx)
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resolver := nameResolver{Info: info, Ctx: ctx, DefaultSchema: model.NewCIStr(defaultSchema)}
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node.Accept(&resolver)
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return errors.Trace(resolver.Err)
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}
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// MockResolveName only serves for test.
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func MockResolveName(node ast.Node, info infoschema.InfoSchema, defaultSchema string, ctx context.Context) error {
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resolver := nameResolver{Info: info, Ctx: ctx, DefaultSchema: model.NewCIStr(defaultSchema)}
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node.Accept(&resolver)
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return resolver.Err
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}
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// nameResolver is the visitor to resolve table name and column name.
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// In general, a reference can only refer to information that are available for it.
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// So children elements are visited in the order that previous elements make information
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// available for following elements.
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//
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// During visiting, information are collected and stored in resolverContext.
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// When we enter a subquery, a new resolverContext is pushed to the contextStack, so subquery
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// information can overwrite outer query information. When we look up for a column reference,
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// we look up from top to bottom in the contextStack.
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type nameResolver struct {
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Info infoschema.InfoSchema
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Ctx context.Context
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DefaultSchema model.CIStr
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Err error
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useOuterContext bool
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contextStack []*resolverContext
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}
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// resolverContext stores information in a single level of select statement
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// that table name and column name can be resolved.
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type resolverContext struct {
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/* For Select Statement. */
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// table map to lookup and check table name conflict.
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tableMap map[string]int
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// table map to lookup and check derived-table(subselect) name conflict.
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derivedTableMap map[string]int
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// tableSources collected in from clause.
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tables []*ast.TableSource
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// result fields collected in select field list.
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fieldList []*ast.ResultField
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// result fields collected in group by clause.
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groupBy []*ast.ResultField
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// The join node stack is used by on condition to find out
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// available tables to reference. On condition can only
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// refer to tables involved in current join.
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joinNodeStack []*ast.Join
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// When visiting TableRefs, tables in this context are not available
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// because it is being collected.
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inTableRefs bool
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// When visiting on condition only tables in current join node are available.
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inOnCondition bool
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// When visiting field list, fieldList in this context are not available.
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inFieldList bool
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// When visiting group by, groupBy fields are not available.
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inGroupBy bool
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// When visiting having, only fieldList and groupBy fields are available.
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inHaving bool
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// When visiting having, checks if the expr is an aggregate function expr.
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inHavingAgg bool
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// OrderBy clause has different resolving rule than group by.
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inOrderBy bool
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// When visiting column name in ByItem, we should know if the column name is in an expression.
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inByItemExpression bool
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// If subquery use outer context.
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useOuterContext bool
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// When visiting multi-table delete stmt table list.
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inDeleteTableList bool
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// When visiting create/drop table statement.
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inCreateOrDropTable bool
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// When visiting show statement.
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inShow bool
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}
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// currentContext gets the current resolverContext.
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func (nr *nameResolver) currentContext() *resolverContext {
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stackLen := len(nr.contextStack)
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if stackLen == 0 {
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return nil
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}
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return nr.contextStack[stackLen-1]
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}
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// pushContext is called when we enter a statement.
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func (nr *nameResolver) pushContext() {
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nr.contextStack = append(nr.contextStack, &resolverContext{
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tableMap: map[string]int{},
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derivedTableMap: map[string]int{},
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})
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}
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// popContext is called when we leave a statement.
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func (nr *nameResolver) popContext() {
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nr.contextStack = nr.contextStack[:len(nr.contextStack)-1]
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}
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// pushJoin is called when we enter a join node.
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func (nr *nameResolver) pushJoin(j *ast.Join) {
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ctx := nr.currentContext()
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ctx.joinNodeStack = append(ctx.joinNodeStack, j)
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}
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// popJoin is called when we leave a join node.
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func (nr *nameResolver) popJoin() {
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ctx := nr.currentContext()
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ctx.joinNodeStack = ctx.joinNodeStack[:len(ctx.joinNodeStack)-1]
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}
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// Enter implements ast.Visitor interface.
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func (nr *nameResolver) Enter(inNode ast.Node) (outNode ast.Node, skipChildren bool) {
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switch v := inNode.(type) {
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case *ast.AdminStmt:
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nr.pushContext()
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case *ast.AggregateFuncExpr:
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ctx := nr.currentContext()
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if ctx.inHaving {
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ctx.inHavingAgg = true
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}
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case *ast.AlterTableStmt:
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nr.pushContext()
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case *ast.AnalyzeTableStmt:
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nr.pushContext()
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case *ast.ByItem:
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if _, ok := v.Expr.(*ast.ColumnNameExpr); !ok {
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// If ByItem is not a single column name expression,
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// the resolving rule is different from order by clause.
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nr.currentContext().inByItemExpression = true
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}
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if nr.currentContext().inGroupBy {
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// make sure item is not aggregate function
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if ast.HasAggFlag(v.Expr) {
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nr.Err = ErrInvalidGroupFuncUse
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return inNode, true
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}
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}
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case *ast.CreateIndexStmt:
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nr.pushContext()
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case *ast.CreateTableStmt:
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nr.pushContext()
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nr.currentContext().inCreateOrDropTable = true
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case *ast.DeleteStmt:
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nr.pushContext()
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case *ast.DeleteTableList:
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nr.currentContext().inDeleteTableList = true
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case *ast.DoStmt:
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nr.pushContext()
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case *ast.DropTableStmt:
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nr.pushContext()
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nr.currentContext().inCreateOrDropTable = true
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case *ast.DropIndexStmt:
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nr.pushContext()
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case *ast.FieldList:
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nr.currentContext().inFieldList = true
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case *ast.GroupByClause:
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nr.currentContext().inGroupBy = true
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case *ast.HavingClause:
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nr.currentContext().inHaving = true
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case *ast.InsertStmt:
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nr.pushContext()
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case *ast.Join:
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nr.pushJoin(v)
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case *ast.OnCondition:
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nr.currentContext().inOnCondition = true
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case *ast.OrderByClause:
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nr.currentContext().inOrderBy = true
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case *ast.SelectStmt:
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nr.pushContext()
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case *ast.SetStmt:
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for _, assign := range v.Variables {
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if cn, ok := assign.Value.(*ast.ColumnNameExpr); ok && cn.Name.Table.L == "" {
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// Convert column name expression to string value expression.
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assign.Value = ast.NewValueExpr(cn.Name.Name.O)
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}
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}
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nr.pushContext()
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case *ast.ShowStmt:
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nr.pushContext()
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nr.currentContext().inShow = true
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nr.fillShowFields(v)
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case *ast.TableRefsClause:
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nr.currentContext().inTableRefs = true
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case *ast.TruncateTableStmt:
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nr.pushContext()
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case *ast.UnionStmt:
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nr.pushContext()
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case *ast.UpdateStmt:
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nr.pushContext()
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}
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return inNode, false
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}
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// Leave implements ast.Visitor interface.
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func (nr *nameResolver) Leave(inNode ast.Node) (node ast.Node, ok bool) {
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switch v := inNode.(type) {
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case *ast.AdminStmt:
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nr.popContext()
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case *ast.AggregateFuncExpr:
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ctx := nr.currentContext()
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if ctx.inHaving {
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ctx.inHavingAgg = false
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}
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case *ast.AlterTableStmt:
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nr.popContext()
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case *ast.AnalyzeTableStmt:
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nr.popContext()
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case *ast.TableName:
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nr.handleTableName(v)
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case *ast.ColumnNameExpr:
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nr.handleColumnName(v)
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case *ast.CreateIndexStmt:
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nr.popContext()
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case *ast.CreateTableStmt:
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nr.popContext()
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case *ast.DeleteTableList:
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nr.currentContext().inDeleteTableList = false
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case *ast.DoStmt:
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nr.popContext()
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case *ast.DropIndexStmt:
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nr.popContext()
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case *ast.DropTableStmt:
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nr.popContext()
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case *ast.TableSource:
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nr.handleTableSource(v)
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case *ast.OnCondition:
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nr.currentContext().inOnCondition = false
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case *ast.Join:
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nr.handleJoin(v)
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nr.popJoin()
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case *ast.TableRefsClause:
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nr.currentContext().inTableRefs = false
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case *ast.FieldList:
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nr.handleFieldList(v)
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nr.currentContext().inFieldList = false
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case *ast.GroupByClause:
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ctx := nr.currentContext()
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ctx.inGroupBy = false
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for _, item := range v.Items {
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switch x := item.Expr.(type) {
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case *ast.ColumnNameExpr:
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ctx.groupBy = append(ctx.groupBy, x.Refer)
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}
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}
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case *ast.HavingClause:
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nr.currentContext().inHaving = false
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case *ast.OrderByClause:
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nr.currentContext().inOrderBy = false
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case *ast.ByItem:
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nr.currentContext().inByItemExpression = false
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case *ast.PositionExpr:
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nr.handlePosition(v)
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case *ast.SelectStmt:
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ctx := nr.currentContext()
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v.SetResultFields(ctx.fieldList)
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if ctx.useOuterContext {
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nr.useOuterContext = true
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}
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nr.popContext()
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case *ast.SetStmt:
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nr.popContext()
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case *ast.ShowStmt:
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nr.popContext()
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case *ast.SubqueryExpr:
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if nr.useOuterContext {
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// TODO: check this
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// If there is a deep nest of subquery, there may be something wrong.
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v.Correlated = true
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nr.useOuterContext = false
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}
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case *ast.TruncateTableStmt:
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nr.popContext()
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case *ast.UnionStmt:
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ctx := nr.currentContext()
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v.SetResultFields(ctx.fieldList)
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if ctx.useOuterContext {
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nr.useOuterContext = true
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}
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nr.popContext()
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case *ast.UnionSelectList:
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nr.handleUnionSelectList(v)
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case *ast.InsertStmt:
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nr.popContext()
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case *ast.DeleteStmt:
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nr.popContext()
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case *ast.UpdateStmt:
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nr.popContext()
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}
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return inNode, nr.Err == nil
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}
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// handleTableName looks up and sets the schema information and result fields for table name.
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func (nr *nameResolver) handleTableName(tn *ast.TableName) {
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if tn.Schema.L == "" {
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tn.Schema = nr.DefaultSchema
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}
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ctx := nr.currentContext()
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if ctx.inCreateOrDropTable {
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// The table may not exist in create table or drop table statement.
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// Skip resolving the table to avoid error.
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return
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}
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if ctx.inDeleteTableList {
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idx, ok := ctx.tableMap[nr.tableUniqueName(tn.Schema, tn.Name)]
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if !ok {
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nr.Err = errors.Errorf("Unknown table %s", tn.Name.O)
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return
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}
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ts := ctx.tables[idx]
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tableName := ts.Source.(*ast.TableName)
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tn.DBInfo = tableName.DBInfo
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tn.TableInfo = tableName.TableInfo
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tn.SetResultFields(tableName.GetResultFields())
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return
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}
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table, err := nr.Info.TableByName(tn.Schema, tn.Name)
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if err != nil {
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nr.Err = errors.Trace(err)
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return
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}
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tn.TableInfo = table.Meta()
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dbInfo, _ := nr.Info.SchemaByName(tn.Schema)
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tn.DBInfo = dbInfo
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rfs := make([]*ast.ResultField, 0, len(tn.TableInfo.Columns))
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tmp := make([]struct {
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ast.ValueExpr
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ast.ResultField
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}, len(tn.TableInfo.Columns))
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sVars := variable.GetSessionVars(nr.Ctx)
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for i, v := range tn.TableInfo.Columns {
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if sVars.InUpdateStmt {
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switch v.State {
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case model.StatePublic, model.StateWriteOnly, model.StateWriteReorganization:
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default:
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continue
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}
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} else {
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if v.State != model.StatePublic {
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continue
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}
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}
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expr := &tmp[i].ValueExpr
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rf := &tmp[i].ResultField
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expr.SetType(&v.FieldType)
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*rf = ast.ResultField{
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Column: v,
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Table: tn.TableInfo,
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DBName: tn.Schema,
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Expr: expr,
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TableName: tn,
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}
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rfs = append(rfs, rf)
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}
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tn.SetResultFields(rfs)
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return
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}
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// handleTableSources checks name duplication
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// and puts the table source in current resolverContext.
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// Note:
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// "select * from t as a join (select 1) as a;" is not duplicate.
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// "select * from t as a join t as a;" is duplicate.
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// "select * from (select 1) as a join (select 1) as a;" is duplicate.
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func (nr *nameResolver) handleTableSource(ts *ast.TableSource) {
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for _, v := range ts.GetResultFields() {
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v.TableAsName = ts.AsName
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}
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ctx := nr.currentContext()
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switch ts.Source.(type) {
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case *ast.TableName:
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var name string
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if ts.AsName.L != "" {
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name = ts.AsName.L
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} else {
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tableName := ts.Source.(*ast.TableName)
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name = nr.tableUniqueName(tableName.Schema, tableName.Name)
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}
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if _, ok := ctx.tableMap[name]; ok {
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nr.Err = errors.Errorf("duplicated table/alias name %s", name)
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return
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}
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ctx.tableMap[name] = len(ctx.tables)
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case *ast.SelectStmt:
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name := ts.AsName.L
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if _, ok := ctx.derivedTableMap[name]; ok {
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nr.Err = errors.Errorf("duplicated table/alias name %s", name)
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return
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}
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ctx.derivedTableMap[name] = len(ctx.tables)
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}
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dupNames := make(map[string]struct{}, len(ts.GetResultFields()))
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for _, f := range ts.GetResultFields() {
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// duplicate column name in one table is not allowed.
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// "select * from (select 1, 1) as a;" is duplicate.
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name := f.ColumnAsName.L
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if name == "" {
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name = f.Column.Name.L
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}
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if _, ok := dupNames[name]; ok {
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nr.Err = errors.Errorf("Duplicate column name '%s'", name)
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return
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}
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dupNames[name] = struct{}{}
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}
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ctx.tables = append(ctx.tables, ts)
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return
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}
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// handleJoin sets result fields for join.
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func (nr *nameResolver) handleJoin(j *ast.Join) {
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if j.Right == nil {
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j.SetResultFields(j.Left.GetResultFields())
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return
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}
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leftLen := len(j.Left.GetResultFields())
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rightLen := len(j.Right.GetResultFields())
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rfs := make([]*ast.ResultField, leftLen+rightLen)
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copy(rfs, j.Left.GetResultFields())
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copy(rfs[leftLen:], j.Right.GetResultFields())
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j.SetResultFields(rfs)
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}
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// handleColumnName looks up and sets ResultField for
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// the column name.
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func (nr *nameResolver) handleColumnName(cn *ast.ColumnNameExpr) {
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ctx := nr.currentContext()
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if ctx.inOnCondition {
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// In on condition, only tables within current join is available.
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nr.resolveColumnNameInOnCondition(cn)
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return
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}
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// Try to resolve the column name form top to bottom in the context stack.
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for i := len(nr.contextStack) - 1; i >= 0; i-- {
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if nr.resolveColumnNameInContext(nr.contextStack[i], cn) {
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// Column is already resolved or encountered an error.
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if i < len(nr.contextStack)-1 {
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// If in subselect, the query use outer query.
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nr.currentContext().useOuterContext = true
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}
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return
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}
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}
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nr.Err = errors.Errorf("unknown column %s", cn.Name.Name.L)
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}
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// resolveColumnNameInContext looks up and sets ResultField for a column with the ctx.
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func (nr *nameResolver) resolveColumnNameInContext(ctx *resolverContext, cn *ast.ColumnNameExpr) bool {
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if ctx.inTableRefs {
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// In TableRefsClause, column reference only in join on condition which is handled before.
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return false
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}
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if ctx.inFieldList {
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// only resolve column using tables.
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return nr.resolveColumnInTableSources(cn, ctx.tables)
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}
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if ctx.inGroupBy {
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// From tables first, then field list.
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// If ctx.InByItemExpression is true, the item is not an identifier.
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// Otherwise it is an identifier.
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if ctx.inByItemExpression {
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// From table first, then field list.
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if nr.resolveColumnInTableSources(cn, ctx.tables) {
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return true
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}
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found := nr.resolveColumnInResultFields(ctx, cn, ctx.fieldList)
|
|
if nr.Err == nil && found {
|
|
// Check if resolved refer is an aggregate function expr.
|
|
if _, ok := cn.Refer.Expr.(*ast.AggregateFuncExpr); ok {
|
|
nr.Err = ErrIllegalReference.Gen("Reference '%s' not supported (reference to group function)", cn.Name.Name.O)
|
|
}
|
|
}
|
|
return found
|
|
}
|
|
// Resolve from table first, then from select list.
|
|
found := nr.resolveColumnInTableSources(cn, ctx.tables)
|
|
if nr.Err != nil {
|
|
return found
|
|
}
|
|
// We should copy the refer here.
|
|
// Because if the ByItem is an identifier, we should check if it
|
|
// is ambiguous even it is already resolved from table source.
|
|
// If the ByItem is not an identifier, we do not need the second check.
|
|
r := cn.Refer
|
|
if nr.resolveColumnInResultFields(ctx, cn, ctx.fieldList) {
|
|
if nr.Err != nil {
|
|
return true
|
|
}
|
|
if r != nil {
|
|
// It is not ambiguous and already resolved from table source.
|
|
// We should restore its Refer.
|
|
cn.Refer = r
|
|
}
|
|
if _, ok := cn.Refer.Expr.(*ast.AggregateFuncExpr); ok {
|
|
nr.Err = ErrIllegalReference.Gen("Reference '%s' not supported (reference to group function)", cn.Name.Name.O)
|
|
}
|
|
return true
|
|
}
|
|
return found
|
|
}
|
|
if ctx.inHaving {
|
|
// First group by, then field list.
|
|
if nr.resolveColumnInResultFields(ctx, cn, ctx.groupBy) {
|
|
return true
|
|
}
|
|
if ctx.inHavingAgg {
|
|
// If cn is in an aggregate function in having clause, check tablesource first.
|
|
if nr.resolveColumnInTableSources(cn, ctx.tables) {
|
|
return true
|
|
}
|
|
}
|
|
return nr.resolveColumnInResultFields(ctx, cn, ctx.fieldList)
|
|
}
|
|
if ctx.inOrderBy {
|
|
if nr.resolveColumnInResultFields(ctx, cn, ctx.groupBy) {
|
|
return true
|
|
}
|
|
if ctx.inByItemExpression {
|
|
// From table first, then field list.
|
|
if nr.resolveColumnInTableSources(cn, ctx.tables) {
|
|
return true
|
|
}
|
|
return nr.resolveColumnInResultFields(ctx, cn, ctx.fieldList)
|
|
}
|
|
// Field list first, then from table.
|
|
if nr.resolveColumnInResultFields(ctx, cn, ctx.fieldList) {
|
|
return true
|
|
}
|
|
return nr.resolveColumnInTableSources(cn, ctx.tables)
|
|
}
|
|
if ctx.inShow {
|
|
return nr.resolveColumnInResultFields(ctx, cn, ctx.fieldList)
|
|
}
|
|
// In where clause.
|
|
return nr.resolveColumnInTableSources(cn, ctx.tables)
|
|
}
|
|
|
|
// resolveColumnNameInOnCondition resolves the column name in current join.
|
|
func (nr *nameResolver) resolveColumnNameInOnCondition(cn *ast.ColumnNameExpr) {
|
|
ctx := nr.currentContext()
|
|
join := ctx.joinNodeStack[len(ctx.joinNodeStack)-1]
|
|
tableSources := appendTableSources(nil, join)
|
|
if !nr.resolveColumnInTableSources(cn, tableSources) {
|
|
nr.Err = errors.Errorf("unkown column name %s", cn.Name.Name.O)
|
|
}
|
|
}
|
|
|
|
func (nr *nameResolver) resolveColumnInTableSources(cn *ast.ColumnNameExpr, tableSources []*ast.TableSource) (done bool) {
|
|
var matchedResultField *ast.ResultField
|
|
tableNameL := cn.Name.Table.L
|
|
columnNameL := cn.Name.Name.L
|
|
if tableNameL != "" {
|
|
var matchedTable ast.ResultSetNode
|
|
for _, ts := range tableSources {
|
|
if tableNameL == ts.AsName.L {
|
|
// different table name.
|
|
matchedTable = ts
|
|
break
|
|
} else if ts.AsName.L != "" {
|
|
// Table as name shadows table real name.
|
|
continue
|
|
}
|
|
if tn, ok := ts.Source.(*ast.TableName); ok {
|
|
if cn.Name.Schema.L != "" && cn.Name.Schema.L != tn.Schema.L {
|
|
continue
|
|
}
|
|
if tableNameL == tn.Name.L {
|
|
matchedTable = ts
|
|
}
|
|
}
|
|
}
|
|
if matchedTable != nil {
|
|
resultFields := matchedTable.GetResultFields()
|
|
for _, rf := range resultFields {
|
|
if rf.ColumnAsName.L == columnNameL || rf.Column.Name.L == columnNameL {
|
|
// resolve column.
|
|
matchedResultField = rf
|
|
break
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
for _, ts := range tableSources {
|
|
rfs := ts.GetResultFields()
|
|
for _, rf := range rfs {
|
|
matchAsName := rf.ColumnAsName.L != "" && rf.ColumnAsName.L == columnNameL
|
|
matchColumnName := rf.ColumnAsName.L == "" && rf.Column.Name.L == columnNameL
|
|
if matchAsName || matchColumnName {
|
|
if matchedResultField != nil {
|
|
nr.Err = errors.Errorf("column %s is ambiguous.", cn.Name.Name.O)
|
|
return true
|
|
}
|
|
matchedResultField = rf
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if matchedResultField != nil {
|
|
// Bind column.
|
|
cn.Refer = matchedResultField
|
|
matchedResultField.Referenced = true
|
|
return true
|
|
}
|
|
return false
|
|
}
|
|
|
|
func (nr *nameResolver) resolveColumnInResultFields(ctx *resolverContext, cn *ast.ColumnNameExpr, rfs []*ast.ResultField) bool {
|
|
var matched *ast.ResultField
|
|
for _, rf := range rfs {
|
|
if cn.Name.Table.L != "" {
|
|
// Check table name
|
|
if rf.TableAsName.L != "" {
|
|
if cn.Name.Table.L != rf.TableAsName.L {
|
|
continue
|
|
}
|
|
} else if cn.Name.Table.L != rf.Table.Name.L {
|
|
continue
|
|
}
|
|
}
|
|
matchAsName := cn.Name.Name.L == rf.ColumnAsName.L
|
|
var matchColumnName bool
|
|
if ctx.inHaving {
|
|
matchColumnName = cn.Name.Name.L == rf.Column.Name.L
|
|
} else {
|
|
matchColumnName = rf.ColumnAsName.L == "" && cn.Name.Name.L == rf.Column.Name.L
|
|
}
|
|
if matchAsName || matchColumnName {
|
|
if rf.Column.Name.L == "" {
|
|
// This is not a real table column, resolve it directly.
|
|
cn.Refer = rf
|
|
rf.Referenced = true
|
|
return true
|
|
}
|
|
if matched == nil {
|
|
matched = rf
|
|
} else {
|
|
sameColumn := matched.TableName == rf.TableName && matched.Column.Name.L == rf.Column.Name.L
|
|
if !sameColumn {
|
|
nr.Err = errors.Errorf("column %s is ambiguous.", cn.Name.Name.O)
|
|
return true
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if matched != nil {
|
|
// If in GroupBy, we clone the ResultField
|
|
if ctx.inGroupBy || ctx.inHaving || ctx.inOrderBy {
|
|
nf := *matched
|
|
expr := matched.Expr
|
|
if cexpr, ok := expr.(*ast.ColumnNameExpr); ok {
|
|
expr = cexpr.Refer.Expr
|
|
}
|
|
nf.Expr = expr
|
|
matched = &nf
|
|
}
|
|
// Bind column.
|
|
cn.Refer = matched
|
|
matched.Referenced = true
|
|
return true
|
|
}
|
|
return false
|
|
}
|
|
|
|
// handleFieldList expands wild card field and sets fieldList in current context.
|
|
func (nr *nameResolver) handleFieldList(fieldList *ast.FieldList) {
|
|
var resultFields []*ast.ResultField
|
|
for _, v := range fieldList.Fields {
|
|
resultFields = append(resultFields, nr.createResultFields(v)...)
|
|
}
|
|
nr.currentContext().fieldList = resultFields
|
|
}
|
|
|
|
func getInnerFromParentheses(expr ast.ExprNode) ast.ExprNode {
|
|
if pexpr, ok := expr.(*ast.ParenthesesExpr); ok {
|
|
return getInnerFromParentheses(pexpr.Expr)
|
|
}
|
|
return expr
|
|
}
|
|
|
|
// createResultFields creates result field list for a single select field.
|
|
func (nr *nameResolver) createResultFields(field *ast.SelectField) (rfs []*ast.ResultField) {
|
|
ctx := nr.currentContext()
|
|
if field.WildCard != nil {
|
|
if len(ctx.tables) == 0 {
|
|
nr.Err = errors.New("No table used.")
|
|
return
|
|
}
|
|
tableRfs := []*ast.ResultField{}
|
|
if field.WildCard.Table.L == "" {
|
|
for _, v := range ctx.tables {
|
|
tableRfs = append(tableRfs, v.GetResultFields()...)
|
|
}
|
|
} else {
|
|
name := nr.tableUniqueName(field.WildCard.Schema, field.WildCard.Table)
|
|
tableIdx, ok1 := ctx.tableMap[name]
|
|
derivedTableIdx, ok2 := ctx.derivedTableMap[name]
|
|
if !ok1 && !ok2 {
|
|
nr.Err = errors.Errorf("unknown table %s.", field.WildCard.Table.O)
|
|
}
|
|
if ok1 {
|
|
tableRfs = ctx.tables[tableIdx].GetResultFields()
|
|
}
|
|
if ok2 {
|
|
tableRfs = append(tableRfs, ctx.tables[derivedTableIdx].GetResultFields()...)
|
|
}
|
|
|
|
}
|
|
for _, trf := range tableRfs {
|
|
trf.Referenced = true
|
|
// Convert it to ColumnNameExpr
|
|
cn := &ast.ColumnName{
|
|
Schema: trf.DBName,
|
|
Table: trf.Table.Name,
|
|
Name: trf.ColumnAsName,
|
|
}
|
|
cnExpr := &ast.ColumnNameExpr{
|
|
Name: cn,
|
|
Refer: trf,
|
|
}
|
|
ast.SetFlag(cnExpr)
|
|
cnExpr.SetType(trf.Expr.GetType())
|
|
rf := *trf
|
|
rf.Expr = cnExpr
|
|
rfs = append(rfs, &rf)
|
|
}
|
|
return
|
|
}
|
|
// The column is visited before so it must has been resolved already.
|
|
rf := &ast.ResultField{ColumnAsName: field.AsName}
|
|
innerExpr := getInnerFromParentheses(field.Expr)
|
|
switch v := innerExpr.(type) {
|
|
case *ast.ColumnNameExpr:
|
|
rf.Column = v.Refer.Column
|
|
rf.Table = v.Refer.Table
|
|
rf.DBName = v.Refer.DBName
|
|
rf.TableName = v.Refer.TableName
|
|
rf.Expr = v
|
|
default:
|
|
rf.Column = &model.ColumnInfo{} // Empty column info.
|
|
rf.Table = &model.TableInfo{} // Empty table info.
|
|
rf.Expr = v
|
|
}
|
|
if field.AsName.L == "" {
|
|
switch x := innerExpr.(type) {
|
|
case *ast.ColumnNameExpr:
|
|
rf.ColumnAsName = model.NewCIStr(x.Name.Name.O)
|
|
case *ast.ValueExpr:
|
|
if innerExpr.Text() != "" {
|
|
rf.ColumnAsName = model.NewCIStr(innerExpr.Text())
|
|
} else {
|
|
rf.ColumnAsName = model.NewCIStr(field.Text())
|
|
}
|
|
default:
|
|
rf.ColumnAsName = model.NewCIStr(field.Text())
|
|
}
|
|
}
|
|
rfs = append(rfs, rf)
|
|
return
|
|
}
|
|
|
|
func appendTableSources(in []*ast.TableSource, resultSetNode ast.ResultSetNode) (out []*ast.TableSource) {
|
|
switch v := resultSetNode.(type) {
|
|
case *ast.TableSource:
|
|
out = append(in, v)
|
|
case *ast.Join:
|
|
out = appendTableSources(in, v.Left)
|
|
if v.Right != nil {
|
|
out = appendTableSources(out, v.Right)
|
|
}
|
|
}
|
|
return
|
|
}
|
|
|
|
func (nr *nameResolver) tableUniqueName(schema, table model.CIStr) string {
|
|
if schema.L != "" && schema.L != nr.DefaultSchema.L {
|
|
return schema.L + "." + table.L
|
|
}
|
|
return table.L
|
|
}
|
|
|
|
func (nr *nameResolver) handlePosition(pos *ast.PositionExpr) {
|
|
ctx := nr.currentContext()
|
|
if pos.N < 1 || pos.N > len(ctx.fieldList) {
|
|
nr.Err = errors.Errorf("Unknown column '%d'", pos.N)
|
|
return
|
|
}
|
|
matched := ctx.fieldList[pos.N-1]
|
|
nf := *matched
|
|
expr := matched.Expr
|
|
if cexpr, ok := expr.(*ast.ColumnNameExpr); ok {
|
|
expr = cexpr.Refer.Expr
|
|
}
|
|
nf.Expr = expr
|
|
pos.Refer = &nf
|
|
pos.Refer.Referenced = true
|
|
if nr.currentContext().inGroupBy {
|
|
// make sure item is not aggregate function
|
|
if ast.HasAggFlag(pos.Refer.Expr) {
|
|
nr.Err = errors.New("group by cannot contain aggregate function")
|
|
}
|
|
}
|
|
}
|
|
|
|
func (nr *nameResolver) handleUnionSelectList(u *ast.UnionSelectList) {
|
|
firstSelFields := u.Selects[0].GetResultFields()
|
|
unionFields := make([]*ast.ResultField, len(firstSelFields))
|
|
// Copy first result fields, because we may change the result field type.
|
|
for i, v := range firstSelFields {
|
|
rf := *v
|
|
col := *v.Column
|
|
rf.Column = &col
|
|
if rf.Column.Flen == 0 {
|
|
rf.Column.Flen = types.UnspecifiedLength
|
|
}
|
|
rf.Expr = &ast.ValueExpr{}
|
|
unionFields[i] = &rf
|
|
}
|
|
nr.currentContext().fieldList = unionFields
|
|
}
|
|
|
|
func (nr *nameResolver) fillShowFields(s *ast.ShowStmt) {
|
|
if s.DBName == "" {
|
|
if s.Table != nil && s.Table.Schema.L != "" {
|
|
s.DBName = s.Table.Schema.O
|
|
} else {
|
|
s.DBName = nr.DefaultSchema.O
|
|
}
|
|
} else if s.Table != nil && s.Table.Schema.L == "" {
|
|
s.Table.Schema = model.NewCIStr(s.DBName)
|
|
}
|
|
var fields []*ast.ResultField
|
|
var (
|
|
names []string
|
|
ftypes []byte
|
|
)
|
|
switch s.Tp {
|
|
case ast.ShowEngines:
|
|
names = []string{"Engine", "Support", "Comment", "Transactions", "XA", "Savepoints"}
|
|
case ast.ShowDatabases:
|
|
names = []string{"Database"}
|
|
case ast.ShowTables:
|
|
names = []string{fmt.Sprintf("Tables_in_%s", s.DBName)}
|
|
if s.Full {
|
|
names = append(names, "Table_type")
|
|
}
|
|
case ast.ShowTableStatus:
|
|
names = []string{"Name", "Engine", "Version", "Row_format", "Rows", "Avg_row_length",
|
|
"Data_length", "Max_data_length", "Index_length", "Data_free", "Auto_increment",
|
|
"Create_time", "Update_time", "Check_time", "Collation", "Checksum",
|
|
"Create_options", "Comment"}
|
|
ftypes = []byte{mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeLonglong, mysql.TypeVarchar, mysql.TypeLonglong, mysql.TypeLonglong,
|
|
mysql.TypeLonglong, mysql.TypeLonglong, mysql.TypeLonglong, mysql.TypeLonglong, mysql.TypeLonglong,
|
|
mysql.TypeDatetime, mysql.TypeDatetime, mysql.TypeDatetime, mysql.TypeVarchar, mysql.TypeVarchar,
|
|
mysql.TypeVarchar, mysql.TypeVarchar}
|
|
case ast.ShowColumns:
|
|
names = table.ColDescFieldNames(s.Full)
|
|
case ast.ShowWarnings:
|
|
names = []string{"Level", "Code", "Message"}
|
|
ftypes = []byte{mysql.TypeVarchar, mysql.TypeLong, mysql.TypeVarchar}
|
|
case ast.ShowCharset:
|
|
names = []string{"Charset", "Description", "Default collation", "Maxlen"}
|
|
ftypes = []byte{mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeLonglong}
|
|
case ast.ShowVariables:
|
|
names = []string{"Variable_name", "Value"}
|
|
case ast.ShowStatus:
|
|
names = []string{"Variable_name", "Value"}
|
|
case ast.ShowCollation:
|
|
names = []string{"Collation", "Charset", "Id", "Default", "Compiled", "Sortlen"}
|
|
ftypes = []byte{mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeLonglong,
|
|
mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeLonglong}
|
|
case ast.ShowCreateTable:
|
|
names = []string{"Table", "Create Table"}
|
|
case ast.ShowGrants:
|
|
names = []string{fmt.Sprintf("Grants for %s", s.User)}
|
|
case ast.ShowTriggers:
|
|
names = []string{"Trigger", "Event", "Table", "Statement", "Timing", "Created",
|
|
"sql_mode", "Definer", "character_set_client", "collation_connection", "Database Collation"}
|
|
ftypes = []byte{mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeVarchar,
|
|
mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeVarchar}
|
|
case ast.ShowProcedureStatus:
|
|
names = []string{}
|
|
ftypes = []byte{}
|
|
case ast.ShowIndex:
|
|
names = []string{"Table", "Non_unique", "Key_name", "Seq_in_index",
|
|
"Column_name", "Collation", "Cardinality", "Sub_part", "Packed",
|
|
"Null", "Index_type", "Comment", "Index_comment"}
|
|
ftypes = []byte{mysql.TypeVarchar, mysql.TypeLonglong, mysql.TypeVarchar, mysql.TypeLonglong,
|
|
mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeLonglong, mysql.TypeLonglong,
|
|
mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeVarchar}
|
|
}
|
|
for i, name := range names {
|
|
f := &ast.ResultField{
|
|
ColumnAsName: model.NewCIStr(name),
|
|
Column: &model.ColumnInfo{}, // Empty column info.
|
|
Table: &model.TableInfo{}, // Empty table info.
|
|
}
|
|
if ftypes == nil || ftypes[i] == 0 {
|
|
// use varchar as the default return column type
|
|
f.Column.Tp = mysql.TypeVarchar
|
|
} else {
|
|
f.Column.Tp = ftypes[i]
|
|
}
|
|
f.Column.Charset, f.Column.Collate = types.DefaultCharsetForType(f.Column.Tp)
|
|
f.Expr = &ast.ValueExpr{}
|
|
f.Expr.SetType(&f.Column.FieldType)
|
|
fields = append(fields, f)
|
|
}
|
|
|
|
if s.Pattern != nil && s.Pattern.Expr == nil {
|
|
rf := fields[0]
|
|
s.Pattern.Expr = &ast.ColumnNameExpr{
|
|
Name: &ast.ColumnName{Name: rf.ColumnAsName},
|
|
}
|
|
ast.SetFlag(s.Pattern)
|
|
}
|
|
s.SetResultFields(fields)
|
|
nr.currentContext().fieldList = fields
|
|
}
|