*: add IF EXISTS and IF NOT EXISTS supported for MariaDB (pingcap…

…#337)
tangenta · Nov 18, 2019 · 42f0c4e · 42f0c4e
1 parent 276b178
commit 42f0c4e
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Showing 4 changed files with 2,173 additions and 2,066 deletions.
diff --git a/ast/ddl.go b/ast/ddl.go
@@ -610,6 +610,10 @@ const (
 type Constraint struct {
 	node
 
+	// only supported by MariaDB 10.0.2+ (ADD {INDEX|KEY}, ADD FOREIGN KEY),
+	// see https://mariadb.com/kb/en/library/alter-table/
+	IfNotExists bool
+
 	Tp   ConstraintType
 	Name string
 
@@ -633,8 +637,14 @@ func (n *Constraint) Restore(ctx *RestoreCtx) error {
 		ctx.WriteKeyWord("PRIMARY KEY")
 	case ConstraintKey:
 		ctx.WriteKeyWord("KEY")
+		if n.IfNotExists {
+			ctx.WriteKeyWord(" IF NOT EXISTS")
+		}
 	case ConstraintIndex:
 		ctx.WriteKeyWord("INDEX")
+		if n.IfNotExists {
+			ctx.WriteKeyWord(" IF NOT EXISTS")
+		}
 	case ConstraintUniq:
 		ctx.WriteKeyWord("UNIQUE")
 	case ConstraintUniqKey:
@@ -670,6 +680,9 @@ func (n *Constraint) Restore(ctx *RestoreCtx) error {
 			ctx.WritePlain(" ")
 		}
 		ctx.WriteKeyWord("FOREIGN KEY ")
+		if n.IfNotExists {
+			ctx.WriteKeyWord("IF NOT EXISTS ")
+		}
 	} else if n.Name != "" {
 		ctx.WritePlain(" ")
 		ctx.WriteName(n.Name)
@@ -1184,6 +1197,10 @@ func (n *CreateViewStmt) Accept(v Visitor) (Node, bool) {
 type CreateIndexStmt struct {
 	ddlNode
 
+	// only supported by MariaDB 10.0.2+,
+	// see https://mariadb.com/kb/en/library/create-index/
+	IfNotExists bool
+
 	IndexName     string
 	Table         *TableName
 	Unique        bool
@@ -1198,6 +1215,9 @@ func (n *CreateIndexStmt) Restore(ctx *RestoreCtx) error {
 		ctx.WriteKeyWord("UNIQUE ")
 	}
 	ctx.WriteKeyWord("INDEX ")
+	if n.IfNotExists {
+		ctx.WriteKeyWord("IF NOT EXISTS ")
+	}
 	ctx.WriteName(n.IndexName)
 	ctx.WriteKeyWord(" ON ")
 	if err := n.Table.Restore(ctx); err != nil {
@@ -1643,6 +1663,14 @@ func (a AlterAlgorithm) String() string {
 type AlterTableSpec struct {
 	node
 
+	// only supported by MariaDB 10.0.2+ (DROP COLUMN, CHANGE COLUMN, MODIFY COLUMN, DROP INDEX, DROP FOREIGN KEY, DROP PARTITION)
+	// see https://mariadb.com/kb/en/library/alter-table/
+	IfExists bool
+
+	// only supported by MariaDB 10.0.2+ (ADD COLUMN, ADD PARTITION)
+	// see https://mariadb.com/kb/en/library/alter-table/
+	IfNotExists bool
+
 	Tp              AlterTableType
 	Name            string
 	Constraint      *Constraint
@@ -1686,6 +1714,9 @@ func (n *AlterTableSpec) Restore(ctx *RestoreCtx) error {
 		}
 	case AlterTableAddColumns:
 		ctx.WriteKeyWord("ADD COLUMN ")
+		if n.IfNotExists {
+			ctx.WriteKeyWord("IF NOT EXISTS ")
+		}
 		if n.Position != nil && len(n.NewColumns) == 1 {
 			if err := n.NewColumns[0].Restore(ctx); err != nil {
 				return errors.Annotatef(err, "An error occurred while restore AlterTableSpec.NewColumns[%d]", 0)
@@ -1715,6 +1746,9 @@ func (n *AlterTableSpec) Restore(ctx *RestoreCtx) error {
 		}
 	case AlterTableDropColumn:
 		ctx.WriteKeyWord("DROP COLUMN ")
+		if n.IfExists {
+			ctx.WriteKeyWord("IF EXISTS ")
+		}
 		if err := n.OldColumnName.Restore(ctx); err != nil {
 			return errors.Annotate(err, "An error occurred while restore AlterTableSpec.OldColumnName")
 		}
@@ -1723,12 +1757,21 @@ func (n *AlterTableSpec) Restore(ctx *RestoreCtx) error {
 		ctx.WriteKeyWord("DROP PRIMARY KEY")
 	case AlterTableDropIndex:
 		ctx.WriteKeyWord("DROP INDEX ")
+		if n.IfExists {
+			ctx.WriteKeyWord("IF EXISTS ")
+		}
 		ctx.WriteName(n.Name)
 	case AlterTableDropForeignKey:
 		ctx.WriteKeyWord("DROP FOREIGN KEY ")
+		if n.IfExists {
+			ctx.WriteKeyWord("IF EXISTS ")
+		}
 		ctx.WriteName(n.Name)
 	case AlterTableModifyColumn:
 		ctx.WriteKeyWord("MODIFY COLUMN ")
+		if n.IfExists {
+			ctx.WriteKeyWord("IF EXISTS ")
+		}
 		if err := n.NewColumns[0].Restore(ctx); err != nil {
 			return errors.Annotate(err, "An error occurred while restore AlterTableSpec.NewColumns[0]")
 		}
@@ -1740,6 +1783,9 @@ func (n *AlterTableSpec) Restore(ctx *RestoreCtx) error {
 		}
 	case AlterTableChangeColumn:
 		ctx.WriteKeyWord("CHANGE COLUMN ")
+		if n.IfExists {
+			ctx.WriteKeyWord("IF EXISTS ")
+		}
 		if err := n.OldColumnName.Restore(ctx); err != nil {
 			return errors.Annotate(err, "An error occurred while restore AlterTableSpec.OldColumnName")
 		}
@@ -1799,6 +1845,9 @@ func (n *AlterTableSpec) Restore(ctx *RestoreCtx) error {
 		ctx.WritePlain(" /* AlterTableForce is not supported */ ")
 	case AlterTableAddPartitions:
 		ctx.WriteKeyWord("ADD PARTITION")
+		if n.IfNotExists {
+			ctx.WriteKeyWord(" IF NOT EXISTS")
+		}
 		if n.PartDefinitions != nil {
 			ctx.WritePlain(" (")
 			for i, def := range n.PartDefinitions {
@@ -1819,6 +1868,9 @@ func (n *AlterTableSpec) Restore(ctx *RestoreCtx) error {
 		ctx.WritePlainf("%d", n.Num)
 	case AlterTableDropPartition:
 		ctx.WriteKeyWord("DROP PARTITION ")
+		if n.IfExists {
+			ctx.WriteKeyWord("IF EXISTS ")
+		}
 		for i, name := range n.PartitionNames {
 			if i != 0 {
 				ctx.WritePlain(",")