Hooks example

engine.go

@@ -32,6 +32,7 @@ import (
 	"github.com/dolthub/go-mysql-server/sql/analyzer"
 	"github.com/dolthub/go-mysql-server/sql/expression"
 	"github.com/dolthub/go-mysql-server/sql/expression/function"
+	_ "github.com/dolthub/go-mysql-server/sql/hooks/noop"
 	"github.com/dolthub/go-mysql-server/sql/plan"
 	"github.com/dolthub/go-mysql-server/sql/planbuilder"
 	"github.com/dolthub/go-mysql-server/sql/rowexec"

sql/hooks/hooks.go

@@ -0,0 +1,110 @@
+// Copyright 2025 Dolthub, 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,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package hooks
+
+import (
+	"github.com/dolthub/go-mysql-server/sql"
+	"github.com/dolthub/go-mysql-server/sql/plan"
+)
+
+// Global is a variable that contains the interface for calling hooks. By default, this contains no-op hooks as
+// integrators may implement their own hooks. This variable should be overwritten by the integrator.
+var Global Hooks
+
+// Hooks is an interface that represents various hooks that are called within a statement's lifecycle.
+type Hooks interface {
+	// Table returns hooks related to direct table statements.
+	Table() Table
+	// TableColumn returns hooks related to table column statements.
+	TableColumn() TableColumn
+}
+
+// Table contains hooks related to direct table statements.
+type Table interface {
+	// Create returns hooks related to CREATE TABLE statements.
+	Create() CreateTable
+	// Rename returns hooks related to RENAME TABLE statements.
+	Rename() RenameTable
+	// Drop returns hooks related to DROP TABLE statements.
+	Drop() DropTable
+}
+
+// TableColumn contains hooks related to table column statements.
+type TableColumn interface {
+	// Add returns hooks related to ALTER TABLE ... ADD COLUMN statements.
+	Add() TableAddColumn
+	// Rename returns hooks related to ALTER TABLE ... RENAME COLUMN statements.
+	Rename() TableRenameColumn
+	// Modify returns hooks related to ALTER TABLE ... MODIFY COLUMN statements.
+	Modify() TableModifyColumn
+	// Drop returns hooks related to ALTER TABLE ... DROP COLUMN statements.
+	Drop() TableDropColumn
+}
+
+// CreateTable contains hooks related to CREATE TABLE statements.
+type CreateTable interface {
+	// PreSQLExecution is called before the final step of statement execution, after analysis.
+	PreSQLExecution(*sql.Context, *plan.CreateTable) (*plan.CreateTable, error)
+	// PostSQLExecution is called after the final step of statement execution, after analysis.
+	PostSQLExecution(*sql.Context, *plan.CreateTable) error
+}
+
+// RenameTable contains hooks related to RENAME TABLE statements.
+type RenameTable interface {
+	// PreSQLExecution is called before the final step of statement execution, after analysis.
+	PreSQLExecution(*sql.Context, *plan.RenameTable) (*plan.RenameTable, error)
+	// PostSQLExecution is called after the final step of statement execution, after analysis.
+	PostSQLExecution(*sql.Context, *plan.RenameTable) error
+}
+
+// DropTable contains hooks related to DROP TABLE statements.
+type DropTable interface {
+	// PreSQLExecution is called before the final step of statement execution, after analysis.
+	PreSQLExecution(*sql.Context, *plan.DropTable) (*plan.DropTable, error)
+	// PostSQLExecution is called after the final step of statement execution, after analysis.
+	PostSQLExecution(*sql.Context, *plan.DropTable) error
+}
+
+// TableAddColumn contains hooks related to ALTER TABLE ... ADD COLUMN statements.
+type TableAddColumn interface {
+	// PreSQLExecution is called before the final step of statement execution, after analysis.
+	PreSQLExecution(*sql.Context, *plan.AddColumn) (*plan.AddColumn, error)
+	// PostSQLExecution is called after the final step of statement execution, after analysis.
+	PostSQLExecution(*sql.Context, *plan.AddColumn) error
+}
+
+// TableRenameColumn contains hooks related to ALTER TABLE ... RENAME COLUMN statements.
+type TableRenameColumn interface {
+	// PreSQLExecution is called before the final step of statement execution, after analysis.
+	PreSQLExecution(*sql.Context, *plan.RenameColumn) (*plan.RenameColumn, error)
+	// PostSQLExecution is called after the final step of statement execution, after analysis.
+	PostSQLExecution(*sql.Context, *plan.RenameColumn) error
+}
+
+// TableModifyColumn contains hooks related to ALTER TABLE ... MODIFY COLUMN statements.
+type TableModifyColumn interface {
+	// PreSQLExecution is called before the final step of statement execution, after analysis.
+	PreSQLExecution(*sql.Context, *plan.ModifyColumn) (*plan.ModifyColumn, error)
+	// PostSQLExecution is called after the final step of statement execution, after analysis.
+	PostSQLExecution(*sql.Context, *plan.ModifyColumn) error
+}
+
+// TableDropColumn contains hooks related to ALTER TABLE ... DROP COLUMN statements.
+type TableDropColumn interface {
+	// PreSQLExecution is called before the final step of statement execution, after analysis.
+	PreSQLExecution(*sql.Context, *plan.DropColumn) (*plan.DropColumn, error)
+	// PostSQLExecution is called after the final step of statement execution, after analysis.
+	PostSQLExecution(*sql.Context, *plan.DropColumn) error
+}

sql/hooks/noop/impl.go

@@ -0,0 +1,192 @@
+// Copyright 2025 Dolthub, 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,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package noop
+
+import (
+	"github.com/dolthub/go-mysql-server/sql"
+	"github.com/dolthub/go-mysql-server/sql/hooks"
+	"github.com/dolthub/go-mysql-server/sql/plan"
+)
+
+// init sets the global hooks to be no-ops by default. It is intended that the variable will be replaced by the
+// integrator.
+func init() {
+	hooks.Global = NoOp{}
+}
+
+// NoOp implements hooks.Hooks while having all operations be no-ops. Integrators may supply their own implementation.
+type NoOp struct{}
+
+var _ hooks.Hooks = NoOp{}
+
+// Table implements the interface hooks.Hooks.
+func (NoOp) Table() hooks.Table {
+	return Table{}
+}
+
+// TableColumn implements the interface hooks.Hooks.
+func (NoOp) TableColumn() hooks.TableColumn {
+	return TableColumn{}
+}
+
+// Table implements no-ops for the hooks.Table interface.
+type Table struct{}
+
+var _ hooks.Table = Table{}
+
+// Create implements the interface hooks.Table.
+func (Table) Create() hooks.CreateTable {
+	return CreateTable{}
+}
+
+// Rename implements the interface hooks.Table.
+func (Table) Rename() hooks.RenameTable {
+	return RenameTable{}
+}
+
+// Drop implements the interface hooks.Table.
+func (Table) Drop() hooks.DropTable {
+	return DropTable{}
+}
+
+// TableColumn implements no-ops for the hooks.TableColumn interface.
+type TableColumn struct{}
+
+var _ hooks.TableColumn = TableColumn{}
+
+// Add implements the interface hooks.TableColumn.
+func (TableColumn) Add() hooks.TableAddColumn {
+	return TableAddColumn{}
+}
+
+// Rename implements the interface hooks.TableColumn.
+func (TableColumn) Rename() hooks.TableRenameColumn {
+	return TableRenameColumn{}
+}
+
+// Modify implements the interface hooks.TableColumn.
+func (TableColumn) Modify() hooks.TableModifyColumn {
+	return TableModifyColumn{}
+}
+
+// Drop implements the interface hooks.TableColumn.
+func (TableColumn) Drop() hooks.TableDropColumn {
+	return TableDropColumn{}
+}
+
+// CreateTable implements no-ops for the hooks.CreateTable interface.
+type CreateTable struct{}
+
+var _ hooks.CreateTable = CreateTable{}
+
+// PreSQLExecution implements the interface hooks.CreateTable.
+func (CreateTable) PreSQLExecution(_ *sql.Context, n *plan.CreateTable) (*plan.CreateTable, error) {
+	return n, nil
+}
+
+// PostSQLExecution implements the interface hooks.CreateTable.
+func (CreateTable) PostSQLExecution(_ *sql.Context, n *plan.CreateTable) error {
+	return nil
+}
+
+// RenameTable implements no-ops for the hooks.RenameTable interface.
+type RenameTable struct{}
+
+var _ hooks.RenameTable = RenameTable{}
+
+// PreSQLExecution implements the interface hooks.RenameTable.
+func (RenameTable) PreSQLExecution(_ *sql.Context, n *plan.RenameTable) (*plan.RenameTable, error) {
+	return n, nil
+}
+
+// PostSQLExecution implements the interface hooks.RenameTable.
+func (RenameTable) PostSQLExecution(_ *sql.Context, n *plan.RenameTable) error {
+	return nil
+}
+
+// DropTable implements no-ops for the hooks.DropTable interface.
+type DropTable struct{}
+
+var _ hooks.DropTable = DropTable{}
+
+// PreSQLExecution implements the interface hooks.DropTable.
+func (DropTable) PreSQLExecution(_ *sql.Context, n *plan.DropTable) (*plan.DropTable, error) {
+	return n, nil
+}
+
+// PostSQLExecution implements the interface hooks.DropTable.
+func (DropTable) PostSQLExecution(_ *sql.Context, n *plan.DropTable) error {
+	return nil
+}
+
+// TableAddColumn implements no-ops for the hooks.TableAddColumn interface.
+type TableAddColumn struct{}
+
+var _ hooks.TableAddColumn = TableAddColumn{}
+
+// PreSQLExecution implements the interface hooks.TableAddColumn.
+func (TableAddColumn) PreSQLExecution(_ *sql.Context, n *plan.AddColumn) (*plan.AddColumn, error) {
+	return n, nil
+}
+
+// PostSQLExecution implements the interface hooks.TableAddColumn.
+func (TableAddColumn) PostSQLExecution(_ *sql.Context, n *plan.AddColumn) error {
+	return nil
+}
+
+// TableRenameColumn implements no-ops for the hooks.TableRenameColumn interface.
+type TableRenameColumn struct{}
+
+var _ hooks.TableRenameColumn = TableRenameColumn{}
+
+// PreSQLExecution implements the interface hooks.TableRenameColumn.
+func (TableRenameColumn) PreSQLExecution(_ *sql.Context, n *plan.RenameColumn) (*plan.RenameColumn, error) {
+	return n, nil
+}
+
+// PostSQLExecution implements the interface hooks.TableRenameColumn.
+func (TableRenameColumn) PostSQLExecution(_ *sql.Context, n *plan.RenameColumn) error {
+	return nil
+}
+
+// TableModifyColumn implements no-ops for the hooks.TableModifyColumn interface.
+type TableModifyColumn struct{}
+
+var _ hooks.TableModifyColumn = TableModifyColumn{}
+
+// PreSQLExecution implements the interface hooks.TableModifyColumn.
+func (TableModifyColumn) PreSQLExecution(_ *sql.Context, n *plan.ModifyColumn) (*plan.ModifyColumn, error) {
+	return n, nil
+}
+
+// PostSQLExecution implements the interface hooks.TableModifyColumn.
+func (TableModifyColumn) PostSQLExecution(_ *sql.Context, n *plan.ModifyColumn) error {
+	return nil
+}
+
+// TableDropColumn implements no-ops for the hooks.TableDropColumn interface.
+type TableDropColumn struct{}
+
+var _ hooks.TableDropColumn = TableDropColumn{}
+
+// PreSQLExecution implements the interface hooks.TableDropColumn.
+func (TableDropColumn) PreSQLExecution(_ *sql.Context, n *plan.DropColumn) (*plan.DropColumn, error) {
+	return n, nil
+}
+
+// PostSQLExecution implements the interface hooks.TableDropColumn.
+func (TableDropColumn) PostSQLExecution(_ *sql.Context, n *plan.DropColumn) error {
+	return nil
+}

sql/plan/alter_table.go

@@ -59,30 +59,6 @@ func (r *RenameTable) IsReadOnly() bool {
 	return false
 }
 
-func (r *RenameTable) RowIter(ctx *sql.Context, row sql.Row) (sql.RowIter, error) {
-	renamer, _ := r.Db.(sql.TableRenamer)
-	viewDb, _ := r.Db.(sql.ViewDatabase)
-	viewRegistry := ctx.GetViewRegistry()
-
-	for i, oldName := range r.OldNames {
-		if tbl, exists := r.tableExists(ctx, oldName); exists {
-			err := r.renameTable(ctx, renamer, tbl, oldName, r.NewNames[i])
-			if err != nil {
-				return nil, err
-			}
-		} else {
-			success, err := r.renameView(ctx, viewDb, viewRegistry, oldName, r.NewNames[i])
-			if err != nil {
-				return nil, err
-			} else if !success {
-				return nil, sql.ErrTableNotFound.New(oldName)
-			}
-		}
-	}
-
-	return sql.RowsToRowIter(sql.NewRow(types.NewOkResult(0))), nil
-}
-
 func (r *RenameTable) WithChildren(children ...sql.Node) (sql.Node, error) {
 	return NillaryWithChildren(r, children...)
 }
@@ -92,15 +68,15 @@ func (*RenameTable) CollationCoercibility(ctx *sql.Context) (collation sql.Colla
 	return sql.Collation_binary, 7
 }
 
-func (r *RenameTable) tableExists(ctx *sql.Context, name string) (sql.Table, bool) {
+func (r *RenameTable) TableExists(ctx *sql.Context, name string) (sql.Table, bool) {
 	tbl, ok, err := r.Db.GetTableInsensitive(ctx, name)
 	if err != nil || !ok {
 		return nil, false
 	}
 	return tbl, true
 }
 
-func (r *RenameTable) renameTable(ctx *sql.Context, renamer sql.TableRenamer, tbl sql.Table, oldName, newName string) error {
+func (r *RenameTable) RenameTable(ctx *sql.Context, renamer sql.TableRenamer, tbl sql.Table, oldName, newName string) error {
 	if renamer == nil {
 		return sql.ErrRenameTableNotSupported.New(r.Db.Name())
 	}
@@ -160,7 +136,7 @@ func (r *RenameTable) renameTable(ctx *sql.Context, renamer sql.TableRenamer, tb
 	return nil
 }
 
-func (r *RenameTable) renameView(ctx *sql.Context, viewDb sql.ViewDatabase, vr *sql.ViewRegistry, oldName, newName string) (bool, error) {
+func (r *RenameTable) RenameView(ctx *sql.Context, viewDb sql.ViewDatabase, vr *sql.ViewRegistry, oldName, newName string) (bool, error) {
 	if viewDb != nil {
 		oldView, exists, err := viewDb.GetViewDefinition(ctx, oldName)
 		if err != nil {