sql: add unimplemented support for drop type

This PR adds unimplemented support for the DROP TYPE command,
as well as adding some missing help/annotations for the CREATE
TYPE command.

Release note: None

docs/generated/sql/bnf/drop_stmt.bnf

@@ -4,4 +4,5 @@ drop_stmt ::=
 	| drop_table_stmt
 	| drop_view_stmt
 	| drop_sequence_stmt
+	| drop_type_stmt
 	| drop_role_stmt

docs/generated/sql/bnf/stmt_block.bnf

@@ -343,6 +343,7 @@ create_ddl_stmt ::=
 	| create_schema_stmt
 	| create_table_stmt
 	| create_table_as_stmt
+	| create_type_stmt
 	| create_view_stmt
 	| create_sequence_stmt
 
@@ -381,6 +382,7 @@ drop_ddl_stmt ::=
 	| drop_table_stmt
 	| drop_view_stmt
 	| drop_sequence_stmt
+	| drop_type_stmt
 
 drop_role_stmt ::=
 	'DROP' role_or_group_or_user string_or_placeholder_list
@@ -1028,6 +1030,9 @@ create_table_as_stmt ::=
 	'CREATE' opt_temp_create_table 'TABLE' table_name create_as_opt_col_list 'AS' select_stmt
 	| 'CREATE' opt_temp_create_table 'TABLE' 'IF' 'NOT' 'EXISTS' table_name create_as_opt_col_list 'AS' select_stmt
 
+create_type_stmt ::=
+	'CREATE' 'TYPE' type_name 'AS' 'ENUM' '(' opt_enum_val_list ')'
+
 create_view_stmt ::=
 	'CREATE' opt_temp 'VIEW' view_name opt_column_list 'AS' select_stmt
 	| 'CREATE' 'OR' 'REPLACE' opt_temp 'VIEW' view_name opt_column_list 'AS' select_stmt
@@ -1093,6 +1098,10 @@ drop_sequence_stmt ::=
 	'DROP' 'SEQUENCE' table_name_list opt_drop_behavior
 	| 'DROP' 'SEQUENCE' 'IF' 'EXISTS' table_name_list opt_drop_behavior
 
+drop_type_stmt ::=
+	'DROP' 'TYPE' type_name_list opt_drop_behavior
+	| 'DROP' 'TYPE' 'IF' 'EXISTS' type_name_list opt_drop_behavior
+
 explain_option_name ::=
 	non_reserved_word
 
@@ -1439,6 +1448,13 @@ create_as_opt_col_list ::=
 	'(' create_as_table_defs ')'
 	| 
 
+type_name ::=
+	db_object_name
+
+opt_enum_val_list ::=
+	enum_val_list
+	| 
+
 opt_temp ::=
 	'TEMPORARY'
 	| 'TEMP'
@@ -1491,6 +1507,9 @@ table_index_name_list ::=
 table_name_list ::=
 	( table_name ) ( ( ',' table_name ) )*
 
+type_name_list ::=
+	( type_name ) ( ( ',' type_name ) )*
+
 non_reserved_word ::=
 	'identifier'
 	| unreserved_keyword
@@ -1789,6 +1808,9 @@ partition_by ::=
 create_as_table_defs ::=
 	( column_name create_as_col_qual_list ) ( ( ',' column_name create_as_col_qual_list | ',' family_def | ',' create_as_constraint_def ) )*
 
+enum_val_list ::=
+	( 'SCONST' ) ( ( ',' 'SCONST' ) )*
+
 common_table_expr ::=
 	table_alias_name opt_column_list 'AS' '(' preparable_stmt ')'
 

pkg/sql/create_type.go

@@ -38,3 +38,4 @@ func (n *createTypeNode) startExec(params runParams) error {
 func (n *createTypeNode) Next(params runParams) (bool, error) { return false, nil }
 func (n *createTypeNode) Values() tree.Datums                 { return tree.Datums{} }
 func (n *createTypeNode) Close(ctx context.Context)           {}
+func (n *createTypeNode) ReadingOwnWrites()                   {}

pkg/sql/drop_type.go

@@ -0,0 +1,41 @@
+// Copyright 2020 The Cockroach Authors.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+package sql
+
+import (
+	"context"
+
+	"github.com/cockroachdb/cockroach/pkg/sql/sem/tree"
+	"github.com/cockroachdb/cockroach/pkg/util/errorutil/unimplemented"
+	"github.com/cockroachdb/errors"
+)
+
+type dropTypeNode struct {
+	n *tree.DropType
+}
+
+// Use to satisfy the linter.
+var _ planNode = &dropTypeNode{n: nil}
+
+func (p *planner) DropType(ctx context.Context, n *tree.DropType) (planNode, error) {
+	return nil, unimplemented.NewWithIssue(27793, "DROP TYPE")
+}
+
+func (n *dropTypeNode) startExec(params runParams) error {
+	return errors.AssertionFailedf(
+		"should not be calling startExec on DROP TYPE node",
+	)
+}
+
+func (n *dropTypeNode) Next(params runParams) (bool, error) { return false, nil }
+func (n *dropTypeNode) Values() tree.Datums                 { return tree.Datums{} }
+func (n *dropTypeNode) Close(ctx context.Context)           {}
+func (n *dropTypeNode) ReadingOwnWrites()                   {}

pkg/sql/logictest/testdata/logic_test/enums

@@ -1,2 +1,8 @@
 statement error pq: unimplemented: CREATE TYPE
 CREATE TYPE mytype AS ENUM ('val1', 'val2')
+
+statement error pq: unimplemented: DROP TYPE
+DROP TYPE mytype
+
+statement error pq: unimplemented: DROP TYPE
+DROP TYPE IF EXISTS mytype

pkg/sql/opaque.go

@@ -89,6 +89,8 @@ func buildOpaque(
 		plan, err = p.DropRole(ctx, n)
 	case *tree.DropTable:
 		plan, err = p.DropTable(ctx, n)
+	case *tree.DropType:
+		plan, err = p.DropType(ctx, n)
 	case *tree.DropView:
 		plan, err = p.DropView(ctx, n)
 	case *tree.DropSequence:
@@ -180,6 +182,7 @@ func init() {
 		&tree.DropDatabase{},
 		&tree.DropIndex{},
 		&tree.DropTable{},
+		&tree.DropType{},
 		&tree.DropView{},
 		&tree.DropRole{},
 		&tree.DropSequence{},

pkg/sql/parser/help_test.go

@@ -125,6 +125,9 @@ func TestContextualHelp(t *testing.T) {
 		{`CREATE TABLE blah AS (SELECT 1) ??`, `CREATE TABLE`},
 		{`CREATE TABLE blah AS SELECT 1 ??`, `SELECT`},
 
+		{`CREATE TYPE blah AS ENUM ??`, `CREATE TYPE`},
+		{`DROP TYPE ??`, `DROP TYPE`},
+
 		{`CREATE SCHEMA IF ??`, `CREATE SCHEMA`},
 		{`CREATE SCHEMA IF NOT ??`, `CREATE SCHEMA`},
 		{`CREATE SCHEMA bli ??`, `CREATE SCHEMA`},

pkg/sql/parser/parse_test.go

@@ -341,6 +341,14 @@ func TestParse(t *testing.T) {
 		{`CREATE TYPE a.b AS ENUM ('a', 'b', 'c')`},
 		{`CREATE TYPE a.b.c AS ENUM ('a', 'b', 'c')`},
 
+		{`DROP TYPE a`},
+		{`DROP TYPE a, b, c`},
+		{`DROP TYPE db.sc.a, sc.a`},
+		{`DROP TYPE IF EXISTS db.sc.a, sc.a`},
+		{`DROP TYPE db.sc.a, sc.a CASCADE`},
+		{`DROP TYPE IF EXISTS db.sc.a, sc.a CASCADE`},
+		{`DROP TYPE IF EXISTS db.sc.a, sc.a RESTRICT`},
+
 		{`DELETE FROM a`},
 		{`EXPLAIN DELETE FROM a`},
 		{`DELETE FROM a.b`},
@@ -3210,7 +3218,6 @@ func TestUnimplementedSyntax(t *testing.T) {
 		{`DROP SUBSCRIPTION a`, 0, `drop subscription`, ``},
 		{`DROP TEXT SEARCH a`, 7821, `drop text`, ``},
 		{`DROP TRIGGER a`, 28296, `drop`, ``},
-		{`DROP TYPE a`, 27793, `drop type`, ``},
 
 		{`DISCARD PLANS`, 0, `discard plans`, ``},
 		{`DISCARD SEQUENCES`, 0, `discard sequences`, ``},

pkg/sql/parser/sql.y

@@ -160,6 +160,9 @@ func (u *sqlSymUnion) unresolvedName() *tree.UnresolvedName {
 func (u *sqlSymUnion) unresolvedObjectName() *tree.UnresolvedObjectName {
     return u.val.(*tree.UnresolvedObjectName)
 }
+func (u *sqlSymUnion) unresolvedObjectNames() []*tree.UnresolvedObjectName {
+    return u.val.([]*tree.UnresolvedObjectName)
+}
 func (u *sqlSymUnion) functionReference() tree.FunctionReference {
     return u.val.(tree.FunctionReference)
 }
@@ -743,6 +746,7 @@ func newNameFromStr(s string) *tree.Name {
 %type <tree.Statement> drop_index_stmt
 %type <tree.Statement> drop_role_stmt
 %type <tree.Statement> drop_table_stmt
+%type <tree.Statement> drop_type_stmt
 %type <tree.Statement> drop_view_stmt
 %type <tree.Statement> drop_sequence_stmt
 
@@ -867,6 +871,7 @@ func newNameFromStr(s string) *tree.Name {
 %type <str> family_name opt_family_name table_alias_name constraint_name target_name zone_name partition_name collation_name
 %type <str> db_object_name_component
 %type <*tree.UnresolvedObjectName> table_name standalone_index_name sequence_name type_name view_name db_object_name simple_db_object_name complex_db_object_name
+%type <[]*tree.UnresolvedObjectName> type_name_list
 %type <str> schema_name
 %type <*tree.UnresolvedName> table_pattern complex_table_pattern
 %type <*tree.UnresolvedName> column_path prefixed_column_path column_path_with_star
@@ -2268,7 +2273,7 @@ comment_text:
 // %Text:
 // CREATE DATABASE, CREATE TABLE, CREATE INDEX, CREATE TABLE AS,
 // CREATE USER, CREATE VIEW, CREATE SEQUENCE, CREATE STATISTICS,
-// CREATE ROLE
+// CREATE ROLE, CREATE TYPE
 create_stmt:
   create_role_stmt     // EXTEND WITH HELP: CREATE ROLE
 | create_ddl_stmt      // help texts in sub-rule
@@ -2329,7 +2334,6 @@ drop_unsupported:
 | DROP SERVER error { return unimplemented(sqllex, "drop server") }
 | DROP SUBSCRIPTION error { return unimplemented(sqllex, "drop subscription") }
 | DROP TEXT error { return unimplementedWithIssueDetail(sqllex, 7821, "drop text") }
-| DROP TYPE error { return unimplementedWithIssueDetail(sqllex, 27793, "drop type") }
 | DROP TRIGGER error { return unimplementedWithIssueDetail(sqllex, 28296, "drop") }
 
 create_ddl_stmt:
@@ -2341,7 +2345,7 @@ create_ddl_stmt:
 | create_table_as_stmt // EXTEND WITH HELP: CREATE TABLE
 // Error case for both CREATE TABLE and CREATE TABLE ... AS in one
 | CREATE opt_temp_create_table TABLE error   // SHOW HELP: CREATE TABLE
-| create_type_stmt     { /* SKIP DOC */ }
+| create_type_stmt     // EXTEND WITH HELP: CREATE TYPE
 | create_view_stmt     // EXTEND WITH HELP: CREATE VIEW
 | create_sequence_stmt // EXTEND WITH HELP: CREATE SEQUENCE
 
@@ -2534,7 +2538,7 @@ discard_stmt:
 // %Category: Group
 // %Text:
 // DROP DATABASE, DROP INDEX, DROP TABLE, DROP VIEW, DROP SEQUENCE,
-// DROP USER, DROP ROLE
+// DROP USER, DROP ROLE, DROP TYPE
 drop_stmt:
   drop_ddl_stmt      // help texts in sub-rule
 | drop_role_stmt     // EXTEND WITH HELP: DROP ROLE
@@ -2547,6 +2551,7 @@ drop_ddl_stmt:
 | drop_table_stmt    // EXTEND WITH HELP: DROP TABLE
 | drop_view_stmt     // EXTEND WITH HELP: DROP VIEW
 | drop_sequence_stmt // EXTEND WITH HELP: DROP SEQUENCE
+| drop_type_stmt     // EXTEND WITH HELP: DROP TYPE
 
 // %Help: DROP VIEW - remove a view
 // %Category: DDL
@@ -2641,6 +2646,41 @@ drop_database_stmt:
   }
 | DROP DATABASE error // SHOW HELP: DROP DATABASE
 
+// %Help: DROP TYPE - remove a type
+// %Category: DDL
+// %Text: DROP TYPE [IF EXISTS] <type_name> [, ...] [CASCASE | RESTRICT]
+// %SeeAlso: WEBDOCS/drop-type.html
+drop_type_stmt:
+  DROP TYPE type_name_list opt_drop_behavior
+  {
+    $$.val = &tree.DropType{
+      Names: $3.unresolvedObjectNames(),
+      IfExists: false,
+      DropBehavior: $4.dropBehavior(),
+    }
+  }
+| DROP TYPE IF EXISTS type_name_list opt_drop_behavior
+  {
+    $$.val = &tree.DropType{
+      Names: $5.unresolvedObjectNames(),
+      IfExists: true,
+      DropBehavior: $6.dropBehavior(),
+    }
+  }
+| DROP TYPE error // SHOW HELP: DROP TYPE
+
+
+type_name_list:
+  type_name
+  {
+    $$.val = []*tree.UnresolvedObjectName{$1.unresolvedObjectName()}
+  }
+| type_name_list ',' type_name
+  {
+    $$.val = append($1.unresolvedObjectNames(), $3.unresolvedObjectName())
+  }
+
+
 // %Help: DROP ROLE - remove a user
 // %Category: Priv
 // %Text: DROP ROLE [IF EXISTS] <user> [, ...]
@@ -5412,20 +5452,24 @@ opt_view_recursive:
   /* EMPTY */ { /* no error */ }
 | RECURSIVE { return unimplemented(sqllex, "create recursive view") }
 
-// CREATE TYPE/DOMAIN is not yet supported by CockroachDB but we
-// want to report it with the right issue number.
+
+// %Help: CREATE TYPE -- create a type
+// %Category: DDL
+// %Text: CREATE TYPE <type_name> AS ENUM (...)
+// %SeeAlso: WEBDOCS/create-type.html
 create_type_stmt:
-  // Record/Composite types.
-  CREATE TYPE type_name AS '(' error      { return unimplementedWithIssue(sqllex, 27792) }
   // Enum types.
-| CREATE TYPE type_name AS ENUM '(' opt_enum_val_list ')'
+  CREATE TYPE type_name AS ENUM '(' opt_enum_val_list ')'
   {
     $$.val = &tree.CreateType{
       TypeName: $3.unresolvedObjectName(),
       Variety: tree.Enum,
       EnumLabels: $7.strs(),
     }
   }
+| CREATE TYPE error // SHOW HELP: CREATE TYPE
+  // Record/Composite types.
+| CREATE TYPE type_name AS '(' error      { return unimplementedWithIssue(sqllex, 27792) }
   // Range types.
 | CREATE TYPE type_name AS RANGE error    { return unimplementedWithIssue(sqllex, 27791) }
   // Base (primitive) types.

pkg/sql/plan.go

@@ -167,6 +167,7 @@ var _ planNode = &createIndexNode{}
 var _ planNode = &createSequenceNode{}
 var _ planNode = &createStatsNode{}
 var _ planNode = &createTableNode{}
+var _ planNode = &createTypeNode{}
 var _ planNode = &CreateRoleNode{}
 var _ planNode = &createViewNode{}
 var _ planNode = &delayedNode{}
@@ -177,6 +178,7 @@ var _ planNode = &dropDatabaseNode{}
 var _ planNode = &dropIndexNode{}
 var _ planNode = &dropSequenceNode{}
 var _ planNode = &dropTableNode{}
+var _ planNode = &dropTypeNode{}
 var _ planNode = &DropRoleNode{}
 var _ planNode = &dropViewNode{}
 var _ planNode = &errorIfRowsNode{}
@@ -237,8 +239,10 @@ var _ planNodeReadingOwnWrites = &alterTableNode{}
 var _ planNodeReadingOwnWrites = &createIndexNode{}
 var _ planNodeReadingOwnWrites = &createSequenceNode{}
 var _ planNodeReadingOwnWrites = &createTableNode{}
+var _ planNodeReadingOwnWrites = &createTypeNode{}
 var _ planNodeReadingOwnWrites = &createViewNode{}
 var _ planNodeReadingOwnWrites = &changePrivilegesNode{}
+var _ planNodeReadingOwnWrites = &dropTypeNode{}
 var _ planNodeReadingOwnWrites = &setZoneConfigNode{}
 
 // planNodeRequireSpool serves as marker for nodes whose parent must

pkg/sql/sem/tree/drop.go

@@ -163,3 +163,30 @@ func (node *DropRole) Format(ctx *FmtCtx) {
 	}
 	ctx.FormatNode(&node.Names)
 }
+
+// DropType represents a DROP TYPE command.
+type DropType struct {
+	Names        []*UnresolvedObjectName
+	IfExists     bool
+	DropBehavior DropBehavior
+}
+
+var _ Statement = &DropType{}
+
+// Format implements the NodeFormatter interface.
+func (node *DropType) Format(ctx *FmtCtx) {
+	ctx.WriteString("DROP TYPE ")
+	if node.IfExists {
+		ctx.WriteString("IF EXISTS ")
+	}
+	for i := range node.Names {
+		if i > 0 {
+			ctx.WriteString(", ")
+		}
+		ctx.FormatNode(node.Names[i])
+	}
+	if node.DropBehavior != DropDefault {
+		ctx.WriteByte(' ')
+		ctx.WriteString(node.DropBehavior.String())
+	}
+}