Add comment information system functions

server/functions/col_description.go

@@ -0,0 +1,41 @@
+// 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 functions
+
+import (
+	"github.com/dolthub/go-mysql-server/sql"
+
+	"github.com/dolthub/doltgresql/server/functions/framework"
+	pgtypes "github.com/dolthub/doltgresql/server/types"
+)
+
+// initColDescription registers the functions to the catalog.
+func initColDescription() {
+	framework.RegisterFunction(col_description)
+}
+
+// col_description represents the PostgreSQL function of the same name, taking the same parameters.
+var col_description = framework.Function2{
+	Name:               "col_description",
+	Return:             pgtypes.Text,
+	Parameters:         [2]pgtypes.DoltgresType{pgtypes.Oid, pgtypes.Int32},
+	IsNonDeterministic: true,
+	Strict:             true,
+	Callable: func(ctx *sql.Context, _ [3]pgtypes.DoltgresType, val1 any, val2 any) (any, error) {
+		// TODO: When we support comments this should return the comment for a table
+		// column, which is specified by the OID of its table and its column number
+		return "", nil
+	},
+}

server/functions/init.go

@@ -36,6 +36,7 @@ func Init() {
 	initCeil()
 	initCharLength()
 	initChr()
+	initColDescription()
 	initCos()
 	initCosd()
 	initCosh()
@@ -64,6 +65,7 @@ func Init() {
 	initMinScale()
 	initMod()
 	initNextVal()
+	initObjDescription()
 	initOctetLength()
 	initPi()
 	initPower()
@@ -78,6 +80,7 @@ func Init() {
 	initRtrim()
 	initScale()
 	initSetVal()
+	initShobjDescription()
 	initSign()
 	initSin()
 	initSind()

server/functions/obj_description.go

@@ -0,0 +1,42 @@
+// 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 functions
+
+import (
+	"github.com/dolthub/go-mysql-server/sql"
+
+	"github.com/dolthub/doltgresql/server/functions/framework"
+	pgtypes "github.com/dolthub/doltgresql/server/types"
+)
+
+// initObjDescription registers the functions to the catalog.
+func initObjDescription() {
+	framework.RegisterFunction(obj_description)
+}
+
+// obj_description represents the PostgreSQL function of the same name, taking the same parameters.
+var obj_description = framework.Function2{
+	Name:               "obj_description",
+	Return:             pgtypes.Text,
+	Parameters:         [2]pgtypes.DoltgresType{pgtypes.Oid, pgtypes.Name},
+	IsNonDeterministic: true,
+	Strict:             true,
+	Callable: func(ctx *sql.Context, _ [3]pgtypes.DoltgresType, val1 any, val2 any) (any, error) {
+		// TODO: When we support comments this should return the comment for a
+		// database object specified by its OID and the name of the containing
+		// system catalog.
+		return "", nil
+	},
+}

server/functions/shobj_description.go

@@ -0,0 +1,42 @@
+// 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 functions
+
+import (
+	"github.com/dolthub/go-mysql-server/sql"
+
+	"github.com/dolthub/doltgresql/server/functions/framework"
+	pgtypes "github.com/dolthub/doltgresql/server/types"
+)
+
+// initShobjDescription registers the functions to the catalog.
+func initShobjDescription() {
+	framework.RegisterFunction(shobj_description)
+}
+
+// shobj_description represents the PostgreSQL function of the same name, taking the same parameters.
+var shobj_description = framework.Function2{
+	Name:               "shobj_description",
+	Return:             pgtypes.Text,
+	Parameters:         [2]pgtypes.DoltgresType{pgtypes.Oid, pgtypes.Name},
+	IsNonDeterministic: true,
+	Strict:             true,
+	Callable: func(ctx *sql.Context, _ [3]pgtypes.DoltgresType, val1 any, val2 any) (any, error) {
+		// TODO: When we support comments this should return the comment for a
+		// shared database object specified by its OID and the name of the
+		// containing system catalog.
+		return "", nil
+	},
+}

testing/go/functions_test.go

@@ -434,5 +434,98 @@ func TestSystemInformationFunctions(t *testing.T) {
 				},
 			},
 		},
+		{
+			Name: "col_description",
+			Assertions: []ScriptTestAssertion{
+				{
+					Query: `SELECT col_description(100, 1);`,
+					Cols:  []string{"col_description"},
+					Expected: []sql.Row{
+						{""},
+					},
+				},
+				{
+					Query:       `SELECT col_description('not_a_table'::regclass, 1);`,
+					ExpectedErr: `relation "not_a_table" does not exist`,
+				},
+				{
+					Query:    `CREATE TABLE test_table (id INT);`,
+					Expected: []sql.Row{},
+				},
+				{
+					Skip:     true, // TODO: Implement column comments
+					Query:    `COMMENT ON COLUMN test_table.id IS 'This is col id';`,
+					Expected: []sql.Row{},
+				},
+				{
+					Skip:  true, // TODO: Implement column object comments
+					Query: `SELECT col_description('test_table'::regclass, 1);`,
+					Cols:  []string{"col_description"},
+					Expected: []sql.Row{
+						{"This is col id"},
+					},
+				},
+			},
+		},
+		{
+			Name: "obj_description",
+			Assertions: []ScriptTestAssertion{
+				{
+					Query: `SELECT obj_description(100, 'pg_class');`,
+					Cols:  []string{"obj_description"},
+					Expected: []sql.Row{
+						{""},
+					},
+				},
+				{
+					Query:       `SELECT obj_description('does-not-exist'::regproc, 'pg_class');`,
+					ExpectedErr: `function "does-not-exist" does not exist`,
+				},
+				{
+					Skip:  true, // TODO: Implement database object comments
+					Query: `SELECT obj_description('sinh'::regproc, 'pg_proc');`,
+					Cols:  []string{"col_description"},
+					Expected: []sql.Row{
+						{"hyperbolic sine"},
+					},
+				},
+			},
+		},
+		{
+			Name: "shobj_description",
+			Assertions: []ScriptTestAssertion{
+				{
+					Query: `SELECT shobj_description(100, 'pg_class');`,
+					Cols:  []string{"shobj_description"},
+					Expected: []sql.Row{
+						{""},
+					},
+				},
+				{
+					Query:       `SELECT shobj_description('does-not-exist'::regproc, 'pg_class');`,
+					ExpectedErr: `function "does-not-exist" does not exist`,
+				},
+				{
+					Skip:     true, // TODO: Implement tablespaces
+					Query:    `CREATE TABLESPACE tblspc_2 LOCATION '/';`,
+					Expected: []sql.Row{},
+				},
+				{
+					Skip:     true, // TODO: Implement shared database object comments
+					Query:    `COMMENT ON TABLESPACE tblspc_2 IS 'Store a few of the things';`,
+					Expected: []sql.Row{},
+				},
+				{
+					Skip: true, // TODO: Implement shared database object comments
+					Query: `SELECT shobj_description(
+                 (SELECT oid FROM pg_tablespace WHERE spcname = 'tblspc_2'),
+                 'pg_tablespace');`,
+					Cols: []string{"shobj_description"},
+					Expected: []sql.Row{
+						{"Store a few of the things"},
+					},
+				},
+			},
+		},
 	})
 }

testing/go/information_schema_test.go

@@ -51,9 +51,48 @@ func TestInfoSchemaTables(t *testing.T) {
 						{"postgres", "public"},
 					},
 				},
+				{
+					Query: `SELECT table_catalog, table_schema, table_name FROM information_schema.tables WHERE table_schema='public';`,
+					Expected: []sql.Row{
+						{"postgres", "public", "test_table"},
+					},
+				},
+				{
+					Query:    `CREATE SCHEMA test_schema;`,
+					Expected: []sql.Row{},
+				},
+				{
+					Query:    `SET SEARCH_PATH TO test_schema;`,
+					Expected: []sql.Row{},
+				},
+				{
+					Query:    `CREATE TABLE test_table2 (id INT);`,
+					Expected: []sql.Row{},
+				},
+				{
+					Query: `SELECT DISTINCT table_schema FROM information_schema.tables order by table_schema;`,
+					Expected: []sql.Row{
+						{"information_schema"}, {"pg_catalog"}, {"public"}, {"test_schema"},
+					},
+				},
+				{
+					Query: `SELECT table_catalog, table_schema FROM information_schema.tables group by table_catalog, table_schema order by table_schema;`,
+					Expected: []sql.Row{
+						{"postgres", "information_schema"},
+						{"postgres", "pg_catalog"},
+						{"postgres", "public"},
+						{"postgres", "test_schema"},
+					},
+				},
+				{
+					Query: `SELECT table_catalog, table_schema, table_name FROM information_schema.tables WHERE table_schema='test_schema';`,
+					Expected: []sql.Row{
+						{"postgres", "test_schema", "test_table2"},
+					},
+				},
 				{
 					Skip:     true, // TODO: need ENUM type for table_type column
-					Query:    "SELECT * FROM PG_catalog.pg_AGGREGATE ORDER BY aggfnoid;",
+					Query:    "SELECT * FROM information_schema.tables ORDER BY table_name;",
 					Expected: []sql.Row{},
 				},
 			},