add parser support for udf (#6968)

add parser support for user-defined function grammar /  query logic handling

Approved by: @daviszhen, @fengttt, @heni02, @iamlinjunhong

pkg/frontend/authenticate.go

@@ -2379,6 +2379,10 @@ handleFailed:
 	return err
 }
 
+func doDropFunction(ctx context.Context, ses *Session, df *tree.DropFunction) error {
+	return nil
+}
+
 // doRevokePrivilege accomplishes the RevokePrivilege statement
 func doRevokePrivilege(ctx context.Context, ses *Session, rp *tree.RevokePrivilege) error {
 	var err error
@@ -3331,6 +3335,10 @@ func determinePrivilegeSetOfStatement(stmt tree.Statement) *privilege {
 		if st.Name != nil {
 			dbName = string(st.Name.SchemaName)
 		}
+	case *tree.CreateFunction:
+		objType = objectTypeDatabase
+		typs = append(typs, PrivilegeTypeCreateView, PrivilegeTypeDatabaseAll, PrivilegeTypeDatabaseOwnership)
+		writeDatabaseAndTableDirectly = true
 	case *tree.DropTable:
 		objType = objectTypeDatabase
 		typs = append(typs, PrivilegeTypeDropTable, PrivilegeTypeDropObject, PrivilegeTypeDatabaseAll, PrivilegeTypeDatabaseOwnership)
@@ -3345,6 +3353,10 @@ func determinePrivilegeSetOfStatement(stmt tree.Statement) *privilege {
 		if len(st.Names) != 0 {
 			dbName = string(st.Names[0].SchemaName)
 		}
+	case *tree.DropFunction:
+		objType = objectTypeDatabase
+		typs = append(typs, PrivilegeTypeCreateView, PrivilegeTypeDatabaseAll, PrivilegeTypeDatabaseOwnership)
+		writeDatabaseAndTableDirectly = true
 	case *tree.Select, *tree.Do:
 		objType = objectTypeTable
 		typs = append(typs, PrivilegeTypeSelect, PrivilegeTypeTableAll, PrivilegeTypeTableOwnership)
@@ -5549,3 +5561,7 @@ handleFailed:
 	}
 	return err
 }
+
+func InitFunction(ctx context.Context, ses *Session, tenant *TenantInfo, cf *tree.CreateFunction) error {
+	return nil
+}

pkg/frontend/authenticate_test.go

@@ -379,6 +379,39 @@ func Test_checkUserExistsOrNot(t *testing.T) {
 	})
 }
 
+func Test_initFunction(t *testing.T) {
+	convey.Convey("init function", t, func() {
+		ctrl := gomock.NewController(t)
+		defer ctrl.Finish()
+
+		pu := config.NewParameterUnit(&config.FrontendParameters{}, nil, nil, nil, nil)
+		pu.SV.SetDefaultValues()
+
+		ctx := context.WithValue(context.TODO(), config.ParameterUnitKey, pu)
+
+		cu := &tree.CreateFunction{
+			Name:       tree.NewFuncName("testFunc"),
+			Args:       nil,
+			ReturnType: tree.NewReturnType("int"),
+			Body:       "",
+			Language:   "sql",
+		}
+
+		tenant := &TenantInfo{
+			Tenant:        sysAccountName,
+			User:          rootName,
+			DefaultRole:   moAdminRoleName,
+			TenantID:      sysAccountID,
+			UserID:        rootID,
+			DefaultRoleID: moAdminRoleID,
+		}
+
+		ses := &Session{}
+		err := InitFunction(ctx, ses, tenant, cu)
+		convey.So(err, convey.ShouldBeNil)
+	})
+}
+
 func Test_initUser(t *testing.T) {
 	convey.Convey("init user", t, func() {
 		ctrl := gomock.NewController(t)
@@ -5452,6 +5485,27 @@ func Test_doRevokePrivilege(t *testing.T) {
 	})
 }
 
+func Test_doDropFunction(t *testing.T) {
+	convey.Convey("drop function", t, func() {
+		ctrl := gomock.NewController(t)
+		defer ctrl.Finish()
+
+		pu := config.NewParameterUnit(&config.FrontendParameters{}, nil, nil, nil, nil)
+		pu.SV.SetDefaultValues()
+
+		ctx := context.WithValue(context.TODO(), config.ParameterUnitKey, pu)
+
+		cu := &tree.DropFunction{
+			Name: tree.NewFuncName("testFunc"),
+			Args: nil,
+		}
+
+		ses := &Session{}
+		err := doDropFunction(ctx, ses, cu)
+		convey.So(err, convey.ShouldBeNil)
+	})
+}
+
 func Test_doDropRole(t *testing.T) {
 	convey.Convey("drop role succ", t, func() {
 		ctrl := gomock.NewController(t)

pkg/frontend/mysql_cmd_executor.go

@@ -1990,6 +1990,17 @@ func (mce *MysqlCmdExecutor) handleDropRole(ctx context.Context, dr *tree.DropRo
 	return doDropRole(ctx, mce.GetSession(), dr)
 }
 
+func (mce *MysqlCmdExecutor) handleCreateFunction(ctx context.Context, cf *tree.CreateFunction) error {
+	ses := mce.GetSession()
+	tenant := ses.GetTenantInfo()
+
+	return InitFunction(ctx, ses, tenant, cf)
+}
+
+func (mce *MysqlCmdExecutor) handleDropFunction(ctx context.Context, df *tree.DropFunction) error {
+	return doDropFunction(ctx, mce.GetSession(), df)
+}
+
 // handleGrantRole grants the role
 func (mce *MysqlCmdExecutor) handleGrantRole(ctx context.Context, gr *tree.GrantRole) error {
 	return doGrantRole(ctx, mce.GetSession(), gr)
@@ -3383,6 +3394,16 @@ func (mce *MysqlCmdExecutor) doComQuery(requestCtx context.Context, sql string)
 			if err = mce.handleDropRole(requestCtx, st); err != nil {
 				goto handleFailed
 			}
+		case *tree.CreateFunction:
+			selfHandle = true
+			if err = mce.handleCreateFunction(requestCtx, st); err != nil {
+				goto handleFailed
+			}
+		case *tree.DropFunction:
+			selfHandle = true
+			if err = mce.handleDropFunction(requestCtx, st); err != nil {
+				goto handleFailed
+			}
 		case *tree.Grant:
 			selfHandle = true
 			ses.InvalidatePrivilegeCache()
@@ -3704,6 +3725,7 @@ func (mce *MysqlCmdExecutor) doComQuery(requestCtx context.Context, sql string)
 			*tree.CreateIndex, *tree.DropIndex, *tree.Insert, *tree.Update,
 			*tree.CreateView, *tree.DropView, *tree.Load, *tree.MoDump,
 			*tree.CreateAccount, *tree.DropAccount, *tree.AlterAccount,
+			*tree.CreateFunction, *tree.DropFunction,
 			*tree.CreateUser, *tree.DropUser, *tree.AlterUser,
 			*tree.CreateRole, *tree.DropRole, *tree.Revoke, *tree.Grant,
 			*tree.SetDefaultRole, *tree.SetRole, *tree.SetPassword, *tree.Delete, *tree.TruncateTable, *tree.Use,

pkg/sql/parsers/dialect/mysql/keywords.go

@@ -526,5 +526,7 @@ func init() {
 		"preceding":                PRECEDING,
 		"following":                FOLLOWING,
 		"groups":                   GROUPS,
+		"returns":                  RETURNS,
+		"extension":                EXTENSION,
 	}
 }