100 lines
2.4 KiB
Go
100 lines
2.4 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 ddl
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import (
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"fmt"
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"github.com/pingcap/tidb/parser/coldef"
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)
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// AlterTableSpecification.Action types.
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// TODO: Add more actions.
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const (
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AlterTableOpt int = iota + 1
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AlterAddColumn
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AlterAddConstr
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AlterDropColumn
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AlterDropPrimaryKey
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AlterDropIndex
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AlterDropForeignKey
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)
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// ColumnPosition Types.
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const (
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ColumnPositionNone int = iota
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ColumnPositionFirst
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ColumnPositionAfter
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)
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// ColumnPosition represents the position of the newly added column.
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type ColumnPosition struct {
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// ColumnPositionNone | ColumnPositionFirst | ColumnPositionAfter
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Type int
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// RelativeColumn is the column which is before the newly added column if type is ColumnPositionAfter.
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RelativeColumn string
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}
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// String implements fmt.Stringer.
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func (cp *ColumnPosition) String() string {
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switch cp.Type {
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case ColumnPositionFirst:
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return "FIRST"
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case ColumnPositionAfter:
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return fmt.Sprintf("AFTER %s", cp.RelativeColumn)
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default:
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return ""
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}
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}
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// AlterSpecification alter table specification.
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type AlterSpecification struct {
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Action int
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Name string
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Constraint *coldef.TableConstraint
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TableOpts []*coldef.TableOpt
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Column *coldef.ColumnDef
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Position *ColumnPosition
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}
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// String implements fmt.Stringer.
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func (as *AlterSpecification) String() string {
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switch as.Action {
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case AlterTableOpt:
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// TODO: Finish this
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return ""
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case AlterAddConstr:
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if as.Constraint != nil {
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return fmt.Sprintf("ADD %s", as.Constraint.String())
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}
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return ""
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case AlterDropColumn:
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return fmt.Sprintf("DROP COLUMN %s", as.Name)
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case AlterDropPrimaryKey:
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return fmt.Sprintf("DROP PRIMARY KEY")
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case AlterDropIndex:
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return fmt.Sprintf("DROP INDEX %s", as.Name)
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case AlterDropForeignKey:
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return fmt.Sprintf("DROP FOREIGN KEY %s", as.Name)
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case AlterAddColumn:
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ps := as.Position.String()
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if len(ps) > 0 {
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return fmt.Sprintf("ADD Column %s %s", as.Column.String(), ps)
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}
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return fmt.Sprintf("ADD Column %s", as.Column.String())
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default:
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return ""
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}
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}
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