chore: import upstream snapshot with attribution

server/ast/constraint_table_def.go

@@ -0,0 +1,136 @@
+// Copyright 2024 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 ast
+
+import (
+	"github.com/cockroachdb/errors"
+
+	vitess "github.com/dolthub/vitess/go/vt/sqlparser"
+
+	"github.com/dolthub/doltgresql/postgres/parser/sem/tree"
+)
+
+// nodeCheckConstraintTableDef converts a tree.CheckConstraintTableDef instance
+// into a vitess.DDL instance that can be executed by GMS. |tableName| identifies
+// the table being altered, and |ifExists| indicates whether the IF EXISTS clause
+// was specified. |notValid| reflects whether the NOT VALID clause was present.
+func nodeCheckConstraintTableDef(
+	ctx *Context,
+	node *tree.CheckConstraintTableDef,
+	tableName vitess.TableName,
+	ifExists bool,
+	notValid bool) (*vitess.DDL, error) {
+
+	if node.NoInherit {
+		return nil, errors.Errorf("NO INHERIT is not yet supported for check constraints")
+	}
+
+	expr, err := nodeExpr(ctx, node.Expr)
+	if err != nil {
+		return nil, err
+	}
+
+	return &vitess.DDL{
+		Action:           "alter",
+		Table:            tableName,
+		IfExists:         ifExists,
+		ConstraintAction: "add",
+		TableSpec: &vitess.TableSpec{
+			Constraints: []*vitess.ConstraintDefinition{
+				{
+					Name: node.Name.String(),
+					Details: &vitess.CheckConstraintDefinition{
+						Expr:     expr,
+						Enforced: true,
+						NotValid: notValid,
+					},
+				},
+			},
+		},
+	}, nil
+}
+
+// nodeAlterTableDropConstraint converts a tree.AlterTableDropConstraint instance
+// into a vitess.DDL instance that can be executed by GMS. |tableName| identifies
+// the table being altered, and |ifExists| indicates whether the IF EXISTS clause
+// was specified.
+func nodeAlterTableDropConstraint(
+	ctx *Context,
+	node *tree.AlterTableDropConstraint,
+	tableName vitess.TableName,
+	ifExists bool) (*vitess.DDL, error) {
+
+	if node.DropBehavior == tree.DropCascade {
+		return nil, errors.Errorf("CASCADE is not yet supported for drop constraint")
+	}
+
+	return &vitess.DDL{
+		Action:             "alter",
+		Table:              tableName,
+		IfExists:           ifExists,
+		ConstraintAction:   "drop",
+		ConstraintIfExists: node.IfExists,
+		TableSpec: &vitess.TableSpec{
+			Constraints: []*vitess.ConstraintDefinition{
+				{Name: node.Constraint.String()},
+			},
+		},
+	}, nil
+}
+
+// nodeUniqueConstraintTableDef converts a tree.UniqueConstraintTableDef instance
+// into a vitess.DDL instance that can be executed by GMS. |tableName| identifies
+// the table being altered, and |ifExists| indicates whether the IF EXISTS clause
+// was specified.
+func nodeUniqueConstraintTableDef(
+	ctx *Context,
+	node *tree.UniqueConstraintTableDef,
+	tableName vitess.TableName,
+	ifExists bool) (*vitess.DDL, error) {
+
+	if len(node.IndexParams.StorageParams) > 0 {
+		return nil, errors.Errorf("STORAGE parameters not yet supported for indexes")
+	}
+
+	if node.IndexParams.Tablespace != "" {
+		return nil, errors.Errorf("TABLESPACE is not yet supported")
+	}
+
+	if node.NullsNotDistinct {
+		return nil, errors.Errorf("NULLS NOT DISTINCT is not yet supported")
+	}
+
+	indexFields, err := nodeIndexElemList(ctx, node.Columns)
+	if err != nil {
+		return nil, err
+	}
+
+	indexType := "unique"
+	if node.PrimaryKey {
+		indexType = "primary"
+	}
+
+	return &vitess.DDL{
+		Action:   "alter",
+		Table:    tableName,
+		IfExists: ifExists,
+		IndexSpec: &vitess.IndexSpec{
+			ToName: vitess.NewColIdent(bareIdentifier(node.Name)),
+			Action: "create",
+			Type:   indexType,
+			Fields: indexFields,
+		},
+	}, nil
+}