Files
tidb/executor/show.go
2017-03-01 14:39:13 +08:00

611 lines
15 KiB
Go

// Copyright 2016 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.
package executor
import (
"bytes"
"fmt"
"sort"
"strings"
"time"
"github.com/juju/errors"
"github.com/pingcap/tidb/ast"
"github.com/pingcap/tidb/context"
"github.com/pingcap/tidb/expression"
"github.com/pingcap/tidb/infoschema"
"github.com/pingcap/tidb/model"
"github.com/pingcap/tidb/mysql"
"github.com/pingcap/tidb/privilege"
"github.com/pingcap/tidb/sessionctx/variable"
"github.com/pingcap/tidb/sessionctx/varsutil"
"github.com/pingcap/tidb/table"
"github.com/pingcap/tidb/terror"
"github.com/pingcap/tidb/util/charset"
"github.com/pingcap/tidb/util/types"
)
// ShowExec represents a show executor.
type ShowExec struct {
Tp ast.ShowStmtType // Databases/Tables/Columns/....
DBName model.CIStr
Table *ast.TableName // Used for showing columns.
Column *ast.ColumnName // Used for `desc table column`.
Flag int // Some flag parsed from sql, such as FULL.
Full bool
User string // Used for show grants.
// Used by show variables
GlobalScope bool
schema *expression.Schema
ctx context.Context
is infoschema.InfoSchema
fetched bool
rows []*Row
cursor int
}
// Schema implements the Executor Schema interface.
func (e *ShowExec) Schema() *expression.Schema {
return e.schema
}
// Next implements Execution Next interface.
func (e *ShowExec) Next() (*Row, error) {
if e.rows == nil {
err := e.fetchAll()
if err != nil {
return nil, errors.Trace(err)
}
}
if e.cursor >= len(e.rows) {
return nil, nil
}
row := e.rows[e.cursor]
e.cursor++
return row, nil
}
func (e *ShowExec) fetchAll() error {
switch e.Tp {
case ast.ShowCharset:
return e.fetchShowCharset()
case ast.ShowCollation:
return e.fetchShowCollation()
case ast.ShowColumns:
return e.fetchShowColumns()
case ast.ShowCreateTable:
return e.fetchShowCreateTable()
case ast.ShowCreateDatabase:
return e.fetchShowCreateDatabase()
case ast.ShowDatabases:
return e.fetchShowDatabases()
case ast.ShowEngines:
return e.fetchShowEngines()
case ast.ShowGrants:
return e.fetchShowGrants()
case ast.ShowIndex:
return e.fetchShowIndex()
case ast.ShowProcedureStatus:
return e.fetchShowProcedureStatus()
case ast.ShowStatus:
return e.fetchShowStatus()
case ast.ShowTables:
return e.fetchShowTables()
case ast.ShowTableStatus:
return e.fetchShowTableStatus()
case ast.ShowTriggers:
return e.fetchShowTriggers()
case ast.ShowVariables:
return e.fetchShowVariables()
case ast.ShowWarnings:
return e.fetchShowWarnings()
case ast.ShowProcessList:
return e.fetchShowProcessList()
case ast.ShowEvents:
// empty result
}
return nil
}
func (e *ShowExec) fetchShowEngines() error {
row := &Row{
Data: types.MakeDatums(
"InnoDB",
"DEFAULT",
"Supports transactions, row-level locking, and foreign keys",
"YES",
"YES",
"YES",
),
}
e.rows = append(e.rows, row)
return nil
}
func (e *ShowExec) fetchShowDatabases() error {
dbs := e.is.AllSchemaNames()
// TODO: let information_schema be the first database
sort.Strings(dbs)
for _, d := range dbs {
e.rows = append(e.rows, &Row{Data: types.MakeDatums(d)})
}
return nil
}
func (e *ShowExec) fetchShowProcessList() error {
sm := e.ctx.GetSessionManager()
if sm == nil {
return nil
}
pl := sm.ShowProcessList()
for _, pi := range pl {
var t uint64
if len(pi.Info) != 0 {
t = uint64(time.Since(pi.Time) / time.Second)
}
row := &Row{
Data: []types.Datum{
types.NewUintDatum(pi.ID),
types.NewStringDatum(pi.User),
types.NewStringDatum(pi.Host),
types.NewStringDatum(pi.DB),
types.NewStringDatum(pi.Command),
types.NewUintDatum(t),
types.NewStringDatum(fmt.Sprintf("%d", pi.State)),
types.NewStringDatum(pi.Info),
},
}
e.rows = append(e.rows, row)
}
return nil
}
func (e *ShowExec) fetchShowTables() error {
if !e.is.SchemaExists(e.DBName) {
return errors.Errorf("Can not find DB: %s", e.DBName)
}
// sort for tables
var tableNames []string
for _, v := range e.is.SchemaTables(e.DBName) {
tableNames = append(tableNames, v.Meta().Name.O)
}
sort.Strings(tableNames)
for _, v := range tableNames {
data := types.MakeDatums(v)
if e.Full {
// TODO: support "VIEW" later if we have supported view feature.
// now, just use "BASE TABLE".
data = append(data, types.NewDatum("BASE TABLE"))
}
e.rows = append(e.rows, &Row{Data: data})
}
return nil
}
func (e *ShowExec) fetchShowTableStatus() error {
if !e.is.SchemaExists(e.DBName) {
return errors.Errorf("Can not find DB: %s", e.DBName)
}
// sort for tables
tables := e.is.SchemaTables(e.DBName)
sort.Sort(table.Slice(tables))
for _, t := range tables {
now := types.CurrentTime(mysql.TypeDatetime)
data := types.MakeDatums(t.Meta().Name.O, "InnoDB", "10", "Compact", 100, 100, 100, 100, 100, 100, 100,
now, now, now, "utf8_general_ci", "", "", t.Meta().Comment)
e.rows = append(e.rows, &Row{Data: data})
}
return nil
}
func (e *ShowExec) fetchShowColumns() error {
tb, err := e.getTable()
if err != nil {
return errors.Trace(err)
}
cols := tb.Cols()
for _, col := range cols {
if e.Column != nil && e.Column.Name.L != col.Name.L {
continue
}
desc := table.NewColDesc(col)
// The FULL keyword causes the output to include the column collation and comments,
// as well as the privileges you have for each column.
row := &Row{}
if e.Full {
row.Data = types.MakeDatums(
desc.Field,
desc.Type,
desc.Collation,
desc.Null,
desc.Key,
desc.DefaultValue,
desc.Extra,
desc.Privileges,
desc.Comment,
)
} else {
row.Data = types.MakeDatums(
desc.Field,
desc.Type,
desc.Null,
desc.Key,
desc.DefaultValue,
desc.Extra,
)
}
e.rows = append(e.rows, row)
}
return nil
}
func (e *ShowExec) fetchShowIndex() error {
tb, err := e.getTable()
if err != nil {
return errors.Trace(err)
}
if tb.Meta().PKIsHandle {
var pkCol *table.Column
for _, col := range tb.Cols() {
if mysql.HasPriKeyFlag(col.Flag) {
pkCol = col
break
}
}
data := types.MakeDatums(
tb.Meta().Name.O, // Table
0, // Non_unique
"PRIMARY", // Key_name
1, // Seq_in_index
pkCol.Name.O, // Column_name
"utf8_bin", // Colation
0, // Cardinality
nil, // Sub_part
nil, // Packed
"", // Null
"BTREE", // Index_type
"", // Comment
"", // Index_comment
)
e.rows = append(e.rows, &Row{Data: data})
}
for _, idx := range tb.Indices() {
for i, col := range idx.Meta().Columns {
nonUniq := 1
if idx.Meta().Unique {
nonUniq = 0
}
var subPart interface{}
if col.Length != types.UnspecifiedLength {
subPart = col.Length
}
data := types.MakeDatums(
tb.Meta().Name.O, // Table
nonUniq, // Non_unique
idx.Meta().Name.O, // Key_name
i+1, // Seq_in_index
col.Name.O, // Column_name
"utf8_bin", // Colation
0, // Cardinality
subPart, // Sub_part
nil, // Packed
"YES", // Null
idx.Meta().Tp.String(), // Index_type
"", // Comment
idx.Meta().Comment, // Index_comment
)
e.rows = append(e.rows, &Row{Data: data})
}
}
return nil
}
// See http://dev.mysql.com/doc/refman/5.7/en/show-character-set.html
func (e *ShowExec) fetchShowCharset() error {
descs := charset.GetAllCharsets()
for _, desc := range descs {
row := &Row{
Data: types.MakeDatums(
desc.Name,
desc.Desc,
desc.DefaultCollation,
desc.Maxlen,
),
}
e.rows = append(e.rows, row)
}
return nil
}
func (e *ShowExec) fetchShowVariables() error {
sessionVars := e.ctx.GetSessionVars()
for _, v := range variable.SysVars {
var err error
var value string
if !e.GlobalScope {
// Try to get Session Scope variable value first.
value, err = varsutil.GetSessionSystemVar(sessionVars, v.Name)
} else {
value, err = varsutil.GetGlobalSystemVar(sessionVars, v.Name)
}
if err != nil {
return errors.Trace(err)
}
row := &Row{Data: types.MakeDatums(v.Name, value)}
e.rows = append(e.rows, row)
}
return nil
}
func (e *ShowExec) fetchShowStatus() error {
statusVars, err := variable.GetStatusVars()
if err != nil {
return errors.Trace(err)
}
for status, v := range statusVars {
if e.GlobalScope && v.Scope == variable.ScopeSession {
continue
}
switch v.Value.(type) {
case []interface{}, nil:
v.Value = fmt.Sprintf("%v", v.Value)
}
value, err := types.ToString(v.Value)
if err != nil {
return errors.Trace(err)
}
row := &Row{Data: types.MakeDatums(status, value)}
e.rows = append(e.rows, row)
}
return nil
}
func (e *ShowExec) fetchShowCreateTable() error {
tb, err := e.getTable()
if err != nil {
return errors.Trace(err)
}
// TODO: let the result more like MySQL.
var buf bytes.Buffer
buf.WriteString(fmt.Sprintf("CREATE TABLE `%s` (\n", tb.Meta().Name.O))
var pkCol *table.Column
for i, col := range tb.Cols() {
buf.WriteString(fmt.Sprintf(" `%s` %s", col.Name.O, col.GetTypeDesc()))
if mysql.HasAutoIncrementFlag(col.Flag) {
buf.WriteString(" NOT NULL AUTO_INCREMENT")
} else {
if mysql.HasNotNullFlag(col.Flag) {
buf.WriteString(" NOT NULL")
}
if !mysql.HasNoDefaultValueFlag(col.Flag) {
switch col.DefaultValue {
case nil:
if !mysql.HasNotNullFlag(col.Flag) {
if mysql.HasTimestampFlag(col.Flag) {
buf.WriteString(" NULL")
}
buf.WriteString(" DEFAULT NULL")
}
case "CURRENT_TIMESTAMP":
buf.WriteString(" DEFAULT CURRENT_TIMESTAMP")
default:
buf.WriteString(fmt.Sprintf(" DEFAULT '%v'", col.DefaultValue))
}
}
if mysql.HasOnUpdateNowFlag(col.Flag) {
buf.WriteString(" ON UPDATE CURRENT_TIMESTAMP")
}
}
if len(col.Comment) > 0 {
buf.WriteString(fmt.Sprintf(" COMMENT '%s'", col.Comment))
}
if i != len(tb.Cols())-1 {
buf.WriteString(",\n")
}
if tb.Meta().PKIsHandle && mysql.HasPriKeyFlag(col.Flag) {
pkCol = col
}
}
if pkCol != nil {
// If PKIsHanle, pk info is not in tb.Indices(). We should handle it here.
buf.WriteString(",\n")
buf.WriteString(fmt.Sprintf(" PRIMARY KEY (`%s`)", pkCol.Name.O))
}
if len(tb.Indices()) > 0 || len(tb.Meta().ForeignKeys) > 0 {
buf.WriteString(",\n")
}
for i, idx := range tb.Indices() {
idxInfo := idx.Meta()
if idxInfo.Primary {
buf.WriteString(" PRIMARY KEY ")
} else if idxInfo.Unique {
buf.WriteString(fmt.Sprintf(" UNIQUE KEY `%s` ", idxInfo.Name.O))
} else {
buf.WriteString(fmt.Sprintf(" KEY `%s` ", idxInfo.Name.O))
}
cols := make([]string, 0, len(idxInfo.Columns))
for _, c := range idxInfo.Columns {
cols = append(cols, c.Name.O)
}
buf.WriteString(fmt.Sprintf("(`%s`)", strings.Join(cols, "`,`")))
if i != len(tb.Indices())-1 {
buf.WriteString(",\n")
}
}
if len(tb.Indices()) > 0 && len(tb.Meta().ForeignKeys) > 0 {
buf.WriteString(",\n")
}
firstFK := true
for _, fk := range tb.Meta().ForeignKeys {
if fk.State != model.StatePublic {
continue
}
if !firstFK {
buf.WriteString(",\n")
}
firstFK = false
cols := make([]string, 0, len(fk.Cols))
for _, c := range fk.Cols {
cols = append(cols, c.O)
}
refCols := make([]string, 0, len(fk.RefCols))
for _, c := range fk.Cols {
refCols = append(refCols, c.O)
}
buf.WriteString(fmt.Sprintf(" CONSTRAINT `%s` FOREIGN KEY (`%s`)", fk.Name.O, strings.Join(cols, "`,`")))
buf.WriteString(fmt.Sprintf(" REFERENCES `%s` (`%s`)", fk.RefTable.O, strings.Join(refCols, "`,`")))
if ast.ReferOptionType(fk.OnDelete) != ast.ReferOptionNoOption {
buf.WriteString(fmt.Sprintf(" ON DELETE %s", ast.ReferOptionType(fk.OnDelete)))
}
if ast.ReferOptionType(fk.OnUpdate) != ast.ReferOptionNoOption {
buf.WriteString(fmt.Sprintf(" ON UPDATE %s", ast.ReferOptionType(fk.OnUpdate)))
}
}
buf.WriteString("\n")
buf.WriteString(") ENGINE=InnoDB")
if s := tb.Meta().Charset; len(s) > 0 {
buf.WriteString(fmt.Sprintf(" DEFAULT CHARSET=%s", s))
}
if tb.Meta().AutoIncID > 0 {
buf.WriteString(fmt.Sprintf(" AUTO_INCREMENT=%d", tb.Meta().AutoIncID))
}
if len(tb.Meta().Comment) > 0 {
buf.WriteString(fmt.Sprintf(" COMMENT='%s'", tb.Meta().Comment))
}
data := types.MakeDatums(tb.Meta().Name.O, buf.String())
e.rows = append(e.rows, &Row{Data: data})
return nil
}
// Compose show create database result.
func (e *ShowExec) fetchShowCreateDatabase() error {
db, ok := e.is.SchemaByName(e.DBName)
if !ok {
return infoschema.ErrDatabaseNotExists.GenByArgs(e.DBName.O)
}
var buf bytes.Buffer
fmt.Fprintf(&buf, "CREATE DATABASE `%s`", db.Name.O)
if s := db.Charset; len(s) > 0 {
fmt.Fprintf(&buf, " /* !40100 DEFAULT CHARACTER SET %s */", s)
}
data := types.MakeDatums(db.Name.O, buf.String())
e.rows = append(e.rows, &Row{Data: data})
return nil
}
func (e *ShowExec) fetchShowCollation() error {
collations := charset.GetCollations()
for _, v := range collations {
isDefault := ""
if v.IsDefault {
isDefault = "Yes"
}
row := &Row{Data: types.MakeDatums(
v.Name,
v.CharsetName,
v.ID,
isDefault,
"Yes",
1,
)}
e.rows = append(e.rows, row)
}
return nil
}
func (e *ShowExec) fetchShowGrants() error {
// Get checker
checker := privilege.GetPrivilegeChecker(e.ctx)
if checker == nil {
return errors.New("miss privilege checker")
}
gs, err := checker.ShowGrants(e.ctx, e.User)
if err != nil {
return errors.Trace(err)
}
for _, g := range gs {
data := types.MakeDatums(g)
e.rows = append(e.rows, &Row{Data: data})
}
return nil
}
func (e *ShowExec) fetchShowTriggers() error {
return nil
}
func (e *ShowExec) fetchShowProcedureStatus() error {
return nil
}
func (e *ShowExec) fetchShowWarnings() error {
warns := e.ctx.GetSessionVars().StmtCtx.GetWarnings()
for _, warn := range warns {
datums := make([]types.Datum, 3)
datums[0] = types.NewStringDatum("Warning")
switch x := warn.(type) {
case *terror.Error:
sqlErr := x.ToSQLError()
datums[1] = types.NewIntDatum(int64(sqlErr.Code))
datums[2] = types.NewStringDatum(sqlErr.Message)
default:
datums[1] = types.NewIntDatum(int64(mysql.ErrUnknown))
datums[2] = types.NewStringDatum(warn.Error())
}
e.rows = append(e.rows, &Row{Data: datums})
}
return nil
}
func (e *ShowExec) getTable() (table.Table, error) {
if e.Table == nil {
return nil, errors.New("table not found")
}
tb, ok := e.is.TableByID(e.Table.TableInfo.ID)
if !ok {
return nil, errors.Errorf("table %s not found", e.Table.Name)
}
return tb, nil
}
// Close implements the Executor Close interface.
func (e *ShowExec) Close() error {
return nil
}