Merge pull request #2681 from dolthub/fulghum/alter-table-extensions

Add support for setting/dropping column type and nullability

Author: fulghum

go.mod

@@ -6,7 +6,7 @@ require (
 	github.com/dolthub/go-icu-regex v0.0.0-20240916130659-0118adc6b662
 	github.com/dolthub/jsonpath v0.0.2-0.20240227200619-19675ab05c71
 	github.com/dolthub/sqllogictest/go v0.0.0-20201107003712-816f3ae12d81
-	github.com/dolthub/vitess v0.0.0-20240919225659-2ad81685e772
+	github.com/dolthub/vitess v0.0.0-20241001235747-8ed913ec76b7
 	github.com/go-kit/kit v0.10.0
 	github.com/go-sql-driver/mysql v1.7.2-0.20231213112541-0004702b931d
 	github.com/gocraft/dbr/v2 v2.7.2

go.sum

@@ -60,6 +60,8 @@ github.com/dolthub/sqllogictest/go v0.0.0-20201107003712-816f3ae12d81 h1:7/v8q9X
 github.com/dolthub/sqllogictest/go v0.0.0-20201107003712-816f3ae12d81/go.mod h1:siLfyv2c92W1eN/R4QqG/+RjjX5W2+gCTRjZxBjI3TY=
 github.com/dolthub/vitess v0.0.0-20240919225659-2ad81685e772 h1:vDwBX7Lc8DnA8Zk0iRIu6slCw0GIUfYfFlYDYJQw8GQ=
 github.com/dolthub/vitess v0.0.0-20240919225659-2ad81685e772/go.mod h1:uBvlRluuL+SbEWTCZ68o0xvsdYZER3CEG/35INdzfJM=
+github.com/dolthub/vitess v0.0.0-20241001235747-8ed913ec76b7 h1:og740P9fUy1NzcmMhhAM/kTOFSjzy4ENzp6XUDc77uY=
+github.com/dolthub/vitess v0.0.0-20241001235747-8ed913ec76b7/go.mod h1:uBvlRluuL+SbEWTCZ68o0xvsdYZER3CEG/35INdzfJM=
 github.com/dustin/go-humanize v0.0.0-20171111073723-bb3d318650d4/go.mod h1:HtrtbFcZ19U5GC7JDqmcUSB87Iq5E25KnS6fMYU6eOk=
 github.com/eapache/go-resiliency v1.1.0/go.mod h1:kFI+JgMyC7bLPUVY133qvEBtVayf5mFgVsvEsIPBvNs=
 github.com/eapache/go-xerial-snappy v0.0.0-20180814174437-776d5712da21/go.mod h1:+020luEh2TKB4/GOp8oxxtq0Daoen/Cii55CzbTV6DU=

sql/planbuilder/ddl.go

@@ -526,6 +526,14 @@ func (b *Builder) buildAlterTableClause(inScope *scope, ddl *ast.DDL) []*scope {
 			outScopes = append(outScopes, b.buildAlterCollationSpec(tableScope, ddl, rt))
 		}
 
+		if ddl.NotNullSpec != nil {
+			outScopes = append(outScopes, b.buildAlterNotNull(tableScope, ddl, rt))
+		}
+
+		if ddl.ColumnTypeSpec != nil {
+			outScopes = append(outScopes, b.buildAlterChangeColumnType(tableScope, ddl, rt))
+		}
+
 		for _, s := range outScopes {
 			if ts, ok := s.node.(sql.SchemaTarget); ok {
 				s.node = b.modifySchemaTarget(s, ts, rt.Schema())
@@ -924,6 +932,56 @@ func (b *Builder) buildAlterAutoIncrement(inScope *scope, ddl *ast.DDL, table *p
 	return
 }
 
+func (b *Builder) buildAlterNotNull(inScope *scope, ddl *ast.DDL, table *plan.ResolvedTable) (outScope *scope) {
+	outScope = inScope
+	spec := ddl.NotNullSpec
+	for _, c := range table.Schema() {
+		if strings.EqualFold(c.Name, spec.Column.String()) {
+			colCopy := *c
+			switch strings.ToLower(spec.Action) {
+			case ast.SetStr:
+				// Set NOT NULL constraint
+				colCopy.Nullable = false
+			case ast.DropStr:
+				// Drop NOT NULL constraint
+				colCopy.Nullable = true
+			default:
+				err := sql.ErrUnsupportedFeature.New(ast.String(ddl))
+				b.handleErr(err)
+			}
+
+			modifyColumn := plan.NewModifyColumnResolved(table, c.Name, colCopy, nil)
+			outScope.node = b.modifySchemaTarget(inScope, modifyColumn, table.Schema())
+			return
+		}
+	}
+	err := sql.ErrTableColumnNotFound.New(table.Name(), spec.Column.String())
+	b.handleErr(err)
+	return
+}
+
+func (b *Builder) buildAlterChangeColumnType(inScope *scope, ddl *ast.DDL, table *plan.ResolvedTable) (outScope *scope) {
+	outScope = inScope
+	spec := ddl.ColumnTypeSpec
+	for _, c := range table.Schema() {
+		if strings.EqualFold(c.Name, spec.Column.String()) {
+			colCopy := *c
+			typ, err := types.ColumnTypeToType(&spec.Type)
+			if err != nil {
+				b.handleErr(err)
+				return
+			}
+			colCopy.Type = typ
+			modifyColumn := plan.NewModifyColumnResolved(table, c.Name, colCopy, nil)
+			outScope.node = b.modifySchemaTarget(inScope, modifyColumn, table.Schema())
+			return
+		}
+	}
+	err := sql.ErrTableColumnNotFound.New(table.Name(), spec.Column.String())
+	b.handleErr(err)
+	return
+}
+
 func (b *Builder) buildAlterDefault(inScope *scope, ddl *ast.DDL, table *plan.ResolvedTable) (outScope *scope) {
 	outScope = inScope
 	switch strings.ToLower(ddl.DefaultSpec.Action) {