add information_schema.constraint_column_usage view (#2270)

Author: jennifersp

server/functions/regtype.go

@@ -80,6 +80,9 @@ var regtypein = framework.Function1{
 		if typeName == "char" && schema == "" {
 			return id.NewType("pg_catalog", "bpchar").AsId(), nil
 		}
+		if typeName == "int" {
+			typeName = "int4"
+		}
 		if internalID, ok := pgtypes.NameToInternalID[typeName]; ok && (internalID.SchemaName() == schema || schema == "") {
 			return internalID.AsId(), nil
 		}

server/functions/setval.go

@@ -89,7 +89,8 @@ func parseRelationName(ctx *sql.Context, name string) (schema string, relation s
 		return "", "", errors.Errorf(`cannot parse relation: %s`, name)
 	}
 
-	// Trim any quotes from the relation name
+	// Trim any quotes from the schema and the relation name
+	schema = strings.Trim(schema, `"`)
 	relation = strings.Trim(relation, `"`)
 
 	return schema, relation, nil

server/tables/information_schema/constraint_column_usage_view.go

@@ -0,0 +1,72 @@
+// Copyright 2026 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 information_schema
+
+import (
+	"github.com/dolthub/go-mysql-server/sql"
+	"github.com/dolthub/go-mysql-server/sql/information_schema"
+
+	"github.com/dolthub/doltgresql/server/functions"
+)
+
+// ConstraintColumnUsageViewName is the name of the CONSTRAINT_COLUMN_USAGE view.
+const ConstraintColumnUsageViewName = "constraint_column_usage"
+
+// newConstraintColumnUsageView creates a new information_schema.CONSTRAINT_COLUMN_USAGE view.
+func newConstraintColumnUsageView() *information_schema.InformationSchemaTable {
+	return &information_schema.InformationSchemaTable{
+		TableName:   ConstraintColumnUsageViewName,
+		TableSchema: constraintColumnUsageSchema,
+		Reader:      constraintColumnUsageRowIter,
+	}
+}
+
+// constraintColumnUsage is the schema for the information_schema.CONSTRAINT_COLUMN_USAGE view.
+var constraintColumnUsageSchema = sql.Schema{
+	{Name: "table_catalog", Type: sql_identifier, Default: nil, Nullable: true, Source: ConstraintColumnUsageViewName},
+	{Name: "table_schema", Type: sql_identifier, Default: nil, Nullable: true, Source: ConstraintColumnUsageViewName},
+	{Name: "table_name", Type: sql_identifier, Default: nil, Nullable: true, Source: ConstraintColumnUsageViewName},
+	{Name: "column_name", Type: character_data, Default: nil, Nullable: true, Source: ConstraintColumnUsageViewName},
+	{Name: "constraint_catalog", Type: character_data, Default: nil, Nullable: true, Source: ConstraintColumnUsageViewName},
+	{Name: "constraint_schema", Type: yes_or_no, Default: nil, Nullable: true, Source: ConstraintColumnUsageViewName},
+	{Name: "constraint_name", Type: yes_or_no, Default: nil, Nullable: true, Source: ConstraintColumnUsageViewName},
+}
+
+// constraintColumnUsageRowIter implements the sql.RowIter for the information_schema.CONSTRAINT_COLUMN_USAGE view.
+func constraintColumnUsageRowIter(ctx *sql.Context, catalog sql.Catalog) (sql.RowIter, error) {
+	var rows []sql.Row
+
+	err := functions.IterateCurrentDatabase(ctx, functions.Callbacks{
+		Check: func(ctx *sql.Context, schema functions.ItemSchema, table functions.ItemTable, check functions.ItemCheck) (cont bool, err error) {
+
+			// TODO: Fill out the rest of the columns.
+			rows = append(rows, sql.Row{
+				schema.Item.Name(),       // table_catalog
+				schema.Item.SchemaName(), // table_schema
+				table.Item.Name(),        // table_name
+				nil,                      // column_name
+				nil,                      // constraint_catalog
+				nil,                      // constraint_schema
+				check.Item.Name,          // constraint_name
+			})
+			return true, nil
+		},
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return sql.RowsToRowIter(rows...), nil
+}

server/tables/information_schema/init.go

@@ -15,6 +15,7 @@
 package information_schema
 
 import (
+	"github.com/dolthub/go-mysql-server/sql"
 	"github.com/dolthub/go-mysql-server/sql/information_schema"
 )
 
@@ -25,4 +26,9 @@ func Init() {
 	information_schema.NewSchemataTable = newSchemataTable
 	information_schema.NewTablesTable = newTablesTable
 	information_schema.NewViewsTable = newViewsTable
+
+	// Postgres-specific tables/views to be added to information_schema database
+	information_schema.NewInformationSchemaTablesToAdd = map[string]sql.Table{
+		ConstraintColumnUsageViewName: newConstraintColumnUsageView(),
+	}
 }

testing/go/functions_test.go

@@ -780,6 +780,12 @@ func TestFunctionsOID(t *testing.T) {
 						{"integer"},
 					},
 				},
+				{
+					Query: `SELECT to_regtype(('int'::regtype)::text);`,
+					Expected: []sql.Row{
+						{"integer"},
+					},
+				},
 				{
 					Query: `SELECT to_regtype((('integer'::regtype)::oid)::text);`,
 					Expected: []sql.Row{
@@ -1393,6 +1399,11 @@ func TestSystemInformationFunctions(t *testing.T) {
 					ExpectedColNames: []string{"pg_get_serial_sequence"},
 					Expected:         []sql.Row{{"public.t1_id_seq"}},
 				},
+				{
+					Query:            `SELECT pg_get_serial_sequence('"public"."t1"', 'id');`,
+					ExpectedColNames: []string{"pg_get_serial_sequence"},
+					Expected:         []sql.Row{{"public.t1_id_seq"}},
+				},
 				{
 					// Test with no schema specified
 					Query:            `SELECT pg_get_serial_sequence('t1', 'id');`,

testing/go/session_test.go

@@ -69,3 +69,36 @@ func TestDiscard(t *testing.T) {
 		},
 	})
 }
+
+func TestRollback(t *testing.T) {
+	RunScripts(t, []ScriptTest{
+		{
+			Name: "Test rollback transaction",
+			SetUpScript: []string{
+				`BEGIN`,
+				`CREATE temporary TABLE test (a INT)`,
+				`insert into test values (1)`,
+			},
+			Assertions: []ScriptTestAssertion{
+				{
+					Query:    "select * from test",
+					Expected: []sql.Row{{1}},
+				},
+				{
+					Query:    "ROLLBACK",
+					Expected: []sql.Row{},
+				},
+				{
+					Query:       "select * from test",
+					ExpectedErr: "table not found",
+					Skip:        true, // temp table should be dropped after ROLLBACK
+				},
+				{
+					Query:    "create temp table test (b int)",
+					Expected: []sql.Row{},
+					Skip:     true, // temp table should be dropped after ROLLBACK
+				},
+			},
+		},
+	})
+}