sql: add SHOW FUNCTIONS command

Release note (sql change): Added the SHOW FUNCTIONS command, which lists user-defined functions. The SHOW FUNCTIONS FROM <schema> syntax is supported too.
cockroachdb · Oct 10, 2022 · a84835a · a84835a
1 parent bfbd07b
commit a84835a
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Showing 15 changed files with 226 additions and 2 deletions.
diff --git a/docs/generated/sql/bnf/BUILD.bazel b/docs/generated/sql/bnf/BUILD.bazel
@@ -216,6 +216,7 @@ FILES = [
     "show_default_privileges_stmt",
     "show_enums",
     "show_full_scans",
+    "show_functions_stmt",
     "show_grants_stmt",
     "show_indexes_stmt",
     "show_jobs",

diff --git a/docs/generated/sql/bnf/show_functions_stmt.bnf b/docs/generated/sql/bnf/show_functions_stmt.bnf
@@ -0,0 +1,4 @@
+show_functions_stmt ::=
+	'SHOW' 'FUNCTIONS' 'FROM' name '.' name
+	| 'SHOW' 'FUNCTIONS' 'FROM' name
+	| 'SHOW' 'FUNCTIONS'
diff --git a/docs/generated/sql/bnf/show_var.bnf b/docs/generated/sql/bnf/show_var.bnf
@@ -9,6 +9,7 @@ show_stmt ::=
 	| show_databases_stmt
 	| show_enums_stmt
 	| show_types_stmt
+	| show_functions_stmt
 	| show_grants_stmt
 	| show_indexes_stmt
 	| show_partitions_stmt

diff --git a/docs/generated/sql/bnf/stmt_block.bnf b/docs/generated/sql/bnf/stmt_block.bnf
@@ -270,6 +270,7 @@ show_stmt ::=
 	| show_databases_stmt
 	| show_enums_stmt
 	| show_types_stmt
+	| show_functions_stmt
 	| show_grants_stmt
 	| show_indexes_stmt
 	| show_partitions_stmt
@@ -809,6 +810,11 @@ show_enums_stmt ::=
 show_types_stmt ::=
 	'SHOW' 'TYPES'
 
+show_functions_stmt ::=
+	'SHOW' 'FUNCTIONS' 'FROM' name '.' name
+	| 'SHOW' 'FUNCTIONS' 'FROM' name
+	| 'SHOW' 'FUNCTIONS'
+
 show_grants_stmt ::=
 	'SHOW' 'GRANTS' opt_on_targets_roles for_grantee_clause
 	| 'SHOW' 'SYSTEM' 'GRANTS' for_grantee_clause

diff --git a/pkg/gen/bnf.bzl b/pkg/gen/bnf.bzl
@@ -216,6 +216,7 @@ BNF_SRCS = [
   "//docs/generated/sql/bnf:show_default_privileges_stmt.bnf",
   "//docs/generated/sql/bnf:show_enums.bnf",
   "//docs/generated/sql/bnf:show_full_scans.bnf",
+  "//docs/generated/sql/bnf:show_functions_stmt.bnf",
   "//docs/generated/sql/bnf:show_grants_stmt.bnf",
   "//docs/generated/sql/bnf:show_indexes_stmt.bnf",
   "//docs/generated/sql/bnf:show_jobs.bnf",

diff --git a/pkg/gen/diagrams.bzl b/pkg/gen/diagrams.bzl
@@ -214,6 +214,7 @@ DIAGRAMS_SRCS = [
   "//docs/generated/sql/bnf:show_default_privileges.html",
   "//docs/generated/sql/bnf:show_enums.html",
   "//docs/generated/sql/bnf:show_full_scans.html",
+  "//docs/generated/sql/bnf:show_functions.html",
   "//docs/generated/sql/bnf:show_grants.html",
   "//docs/generated/sql/bnf:show_indexes.html",
   "//docs/generated/sql/bnf:show_jobs.html",

diff --git a/pkg/gen/docs.bzl b/pkg/gen/docs.bzl
@@ -228,6 +228,7 @@ DOCS_SRCS = [
   "//docs/generated/sql/bnf:show_default_privileges_stmt.bnf",
   "//docs/generated/sql/bnf:show_enums.bnf",
   "//docs/generated/sql/bnf:show_full_scans.bnf",
+  "//docs/generated/sql/bnf:show_functions_stmt.bnf",
   "//docs/generated/sql/bnf:show_grants_stmt.bnf",
   "//docs/generated/sql/bnf:show_indexes_stmt.bnf",
   "//docs/generated/sql/bnf:show_jobs.bnf",

diff --git a/pkg/sql/delegate/BUILD.bazel b/pkg/sql/delegate/BUILD.bazel
@@ -15,6 +15,7 @@ go_library(
         "show_enums.go",
         "show_full_table_scans.go",
         "show_function.go",
+        "show_functions.go",
         "show_grants.go",
         "show_jobs.go",
         "show_partitions.go",

diff --git a/pkg/sql/delegate/delegate.go b/pkg/sql/delegate/delegate.go
@@ -127,6 +127,9 @@ func TryDelegate(
 	case *tree.ShowSyntax:
 		return d.delegateShowSyntax(t)
 
+	case *tree.ShowFunctions:
+		return d.delegateShowFunctions(t)
+
 	case *tree.ShowTables:
 		return d.delegateShowTables(t)
 

diff --git a/pkg/sql/delegate/show_functions.go b/pkg/sql/delegate/show_functions.go
@@ -0,0 +1,83 @@
+// Copyright 2022 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 delegate
+
+import (
+	"fmt"
+
+	"github.com/cockroachdb/cockroach/pkg/sql/lexbase"
+	"github.com/cockroachdb/cockroach/pkg/sql/opt/cat"
+	"github.com/cockroachdb/cockroach/pkg/sql/sem/catconstants"
+	"github.com/cockroachdb/cockroach/pkg/sql/sem/tree"
+)
+
+// delegateShowFunctions implements SHOW FUNCTIONS which returns all the
+// user-defined functions.
+// Privileges: None.
+//
+//	Notes: postgres does not have a SHOW FUNCTIONS statement.
+func (d *delegator) delegateShowFunctions(n *tree.ShowFunctions) (tree.Statement, error) {
+	flags := cat.Flags{AvoidDescriptorCaches: true}
+	_, name, err := d.catalog.ResolveSchema(d.ctx, flags, &n.ObjectNamePrefix)
+	if err != nil {
+		return nil, err
+	}
+	// If we're resolved a one-part name into <db>.public (which is the behavior
+	// of ResolveSchema, not for any obviously good reason), rework the resolved
+	// name to have an explicit catalog but no explicit schema. This would arise
+	// when doing SHOW FUNCTIONS FROM <db>. Without this logic, we would not show the
+	// tables from other schemas than public.
+	if name.ExplicitSchema && name.ExplicitCatalog && name.SchemaName == tree.PublicSchemaName &&
+		n.ExplicitSchema && !n.ExplicitCatalog && n.SchemaName == name.CatalogName {
+		name.SchemaName, name.ExplicitSchema = "", false
+	}
+	var schemaClause string
+	if name.ExplicitSchema {
+		schema := lexbase.EscapeSQLString(name.Schema())
+		if name.Schema() == catconstants.PgTempSchemaName {
+			schema = lexbase.EscapeSQLString(d.evalCtx.SessionData().SearchPath.GetTemporarySchemaName())
+		}
+		schemaClause = fmt.Sprintf("AND n.nspname = %s", schema)
+	} else {
+		// These must be custom defined until the sql <-> sql/delegate cyclic dependency
+		// is resolved. When we have that, we should read the names off "virtualSchemas" instead.
+		schemaClause = "AND n.nspname NOT IN ('information_schema', 'pg_catalog', 'crdb_internal', 'pg_extension')"
+	}
+
+	const getFunctionsQuery = `
+SELECT n.nspname as schema_name,
+  p.proname as function_name,
+  pg_catalog.pg_get_function_result(p.oid) as result_data_type,
+  pg_catalog.pg_get_function_identity_arguments(p.oid) as argument_data_types,
+  CASE p.prokind
+	  WHEN 'a' THEN 'agg'
+	  WHEN 'w' THEN 'window'
+	  WHEN 'p' THEN 'proc'
+    ELSE 'func'
+  END as function_type,
+  CASE
+    WHEN p.provolatile = 'i' THEN 'immutable'
+    WHEN p.provolatile = 's' THEN 'stable'
+    WHEN p.provolatile = 'v' THEN 'volatile'
+  END as volatility
+FROM %[1]s.pg_catalog.pg_proc p
+LEFT JOIN %[1]s.pg_catalog.pg_namespace n ON n.oid = p.pronamespace
+WHERE true
+%[2]s
+ORDER BY 1, 2, 4;
+`
+	query := fmt.Sprintf(
+		getFunctionsQuery,
+		&name.CatalogName,
+		schemaClause,
+	)
+	return parse(query)
+}
diff --git a/pkg/sql/logictest/testdata/logic_test/udf b/pkg/sql/logictest/testdata/logic_test/udf
@@ -637,6 +637,70 @@ test           public         100137       test_priv_f1()      root     EXECUTE
 test           public         100138       test_priv_f2(int8)  root     EXECUTE         true
 test           test_priv_sc1  100139       test_priv_f3()      root     EXECUTE         true
 
+query TTTTTT colnames
+SHOW FUNCTIONS
+----
+schema_name    function_name  result_data_type  argument_data_types  function_type  volatility
+public         a              int8              int8                 func           volatile
+public         b              int8              int8                 func           volatile
+public         c              int8              int8, int8           func           volatile
+public         d              int4              int2                 func           volatile
+public         f              int8              notmyworkday         func           immutable
+public         f_no_ref       int8              int8                 func           immutable
+public         proc_f         int8              int8                 func           volatile
+public         proc_f         text              text, int8           func           immutable
+public         test_priv_f1   int8              ·                    func           volatile
+public         test_priv_f2   int8              int8                 func           volatile
+public         test_tbl_f     int8              ·                    func           immutable
+public         test_vf_f      text              ·                    func           volatile
+public         test_vf_g      text              ·                    func           volatile
+sc             proc_f_2       text              text                 func           volatile
+test_priv_sc1  test_priv_f3   int8              ·                    func           volatile
+
+query TTTTTT colnames
+SHOW FUNCTIONS FROM public
+----
+schema_name  function_name  result_data_type  argument_data_types  function_type  volatility
+public       a              int8              int8                 func           volatile
+public       b              int8              int8                 func           volatile
+public       c              int8              int8, int8           func           volatile
+public       d              int4              int2                 func           volatile
+public       f              int8              notmyworkday         func           immutable
+public       f_no_ref       int8              int8                 func           immutable
+public       proc_f         int8              int8                 func           volatile
+public       proc_f         text              text, int8           func           immutable
+public       test_priv_f1   int8              ·                    func           volatile
+public       test_priv_f2   int8              int8                 func           volatile
+public       test_tbl_f     int8              ·                    func           immutable
+public       test_vf_f      text              ·                    func           volatile
+public       test_vf_g      text              ·                    func           volatile
+
+query TTTTTT colnames
+SHOW FUNCTIONS FROM test_priv_sc1
+----
+schema_name    function_name  result_data_type  argument_data_types  function_type  volatility
+test_priv_sc1  test_priv_f3   int8              ·                    func           volatile
+
+query TTTTTT colnames
+SHOW FUNCTIONS FROM test
+----
+schema_name    function_name  result_data_type  argument_data_types  function_type  volatility
+public         a              int8              int8                 func           volatile
+public         b              int8              int8                 func           volatile
+public         c              int8              int8, int8           func           volatile
+public         d              int4              int2                 func           volatile
+public         f              int8              notmyworkday         func           immutable
+public         f_no_ref       int8              int8                 func           immutable
+public         proc_f         int8              int8                 func           volatile
+public         proc_f         text              text, int8           func           immutable
+public         test_priv_f1   int8              ·                    func           volatile
+public         test_priv_f2   int8              int8                 func           volatile
+public         test_tbl_f     int8              ·                    func           immutable
+public         test_vf_f      text              ·                    func           volatile
+public         test_vf_g      text              ·                    func           volatile
+sc             proc_f_2       text              text                 func           volatile
+test_priv_sc1  test_priv_f3   int8              ·                    func           volatile
+
 statement ok
 GRANT EXECUTE ON FUNCTION test_priv_f1(), test_priv_f2(int), test_priv_sc1.test_priv_f3 TO udf_test_user WITH GRANT OPTION;
 

diff --git a/pkg/sql/parser/help_test.go b/pkg/sql/parser/help_test.go
@@ -370,6 +370,10 @@ func TestContextualHelp(t *testing.T) {
 		{`SHOW ENUMS ??`, `SHOW ENUMS`},
 		{`SHOW TYPES ??`, `SHOW TYPES`},
 
+		{`SHOW FUNCTIONS ??`, `SHOW FUNCTIONS`},
+		{`SHOW FUNCTIONS FROM ??`, `SHOW FUNCTIONS`},
+		{`SHOW FUNCTIONS FROM blah ??`, `SHOW FUNCTIONS`},
+
 		{`SHOW GRANTS ON ??`, `SHOW GRANTS`},
 		{`SHOW GRANTS ON foo FOR ??`, `SHOW GRANTS`},
 		{`SHOW GRANTS ON foo FOR bar ??`, `SHOW GRANTS`},

diff --git a/pkg/sql/parser/sql.y b/pkg/sql/parser/sql.y
@@ -1189,6 +1189,7 @@ func (u *sqlSymUnion) functionObjs() tree.FuncObjs {
 %type <tree.Statement> show_default_privileges_stmt
 %type <tree.Statement> show_enums_stmt
 %type <tree.Statement> show_fingerprints_stmt
+%type <tree.Statement> show_functions_stmt
 %type <tree.Statement> show_grants_stmt
 %type <tree.Statement> show_histogram_stmt
 %type <tree.Statement> show_indexes_stmt
@@ -6228,8 +6229,8 @@ zone_value:
 // %Text:
 // SHOW BACKUP, SHOW CLUSTER SETTING, SHOW COLUMNS, SHOW CONSTRAINTS,
 // SHOW CREATE, SHOW CREATE SCHEDULES, SHOW DATABASES, SHOW ENUMS, SHOW
-// FUNCTION, SHOW HISTOGRAM, SHOW INDEXES, SHOW PARTITIONS, SHOW JOBS, SHOW
-// STATEMENTS, SHOW RANGE, SHOW RANGES, SHOW REGIONS, SHOW SURVIVAL GOAL,
+// FUNCTION, SHOW FUNCTIONS, SHOW HISTOGRAM, SHOW INDEXES, SHOW PARTITIONS, SHOW JOBS,
+// SHOW STATEMENTS, SHOW RANGE, SHOW RANGES, SHOW REGIONS, SHOW SURVIVAL GOAL,
 // SHOW ROLES, SHOW SCHEMAS, SHOW SEQUENCES, SHOW SESSION, SHOW SESSIONS,
 // SHOW STATISTICS, SHOW SYNTAX, SHOW TABLES, SHOW TRACE, SHOW TRANSACTION,
 // SHOW TRANSACTIONS, SHOW TRANSFER, SHOW TYPES, SHOW USERS, SHOW LAST QUERY STATISTICS,
@@ -6247,6 +6248,7 @@ show_stmt:
 | show_enums_stmt            // EXTEND WITH HELP: SHOW ENUMS
 | show_types_stmt            // EXTEND WITH HELP: SHOW TYPES
 | show_fingerprints_stmt
+| show_functions_stmt        // EXTEND WITH HELP: SHOW FUNCTIONS
 | show_grants_stmt           // EXTEND WITH HELP: SHOW GRANTS
 | show_histogram_stmt        // EXTEND WITH HELP: SHOW HISTOGRAM
 | show_indexes_stmt          // EXTEND WITH HELP: SHOW INDEXES
@@ -7173,6 +7175,34 @@ show_tables_stmt:
   }
 | SHOW TABLES error // SHOW HELP: SHOW TABLES
 
+// %Help: SHOW FUNCTIONS - list functions
+// %Category: DDL
+// %Text: SHOW FUNCTIONS [FROM <databasename> [ . <schemaname> ] ]
+show_functions_stmt:
+  SHOW FUNCTIONS FROM name '.' name
+  {
+    $$.val = &tree.ShowFunctions{ObjectNamePrefix:tree.ObjectNamePrefix{
+        CatalogName: tree.Name($4),
+        ExplicitCatalog: true,
+        SchemaName: tree.Name($6),
+        ExplicitSchema: true,
+    }}
+  }
+| SHOW FUNCTIONS FROM name
+  {
+    $$.val = &tree.ShowFunctions{ObjectNamePrefix:tree.ObjectNamePrefix{
+        // Note: the schema name may be interpreted as database name,
+        // see name_resolution.go.
+        SchemaName: tree.Name($4),
+        ExplicitSchema: true,
+    }}
+  }
+| SHOW FUNCTIONS
+  {
+    $$.val = &tree.ShowFunctions{}
+  }
+| SHOW FUNCTIONS error // SHOW HELP: SHOW FUNCTIONS
+
 // %Help: SHOW TRANSACTIONS - list open client transactions across the cluster
 // %Category: Misc
 // %Text: SHOW [ALL] [CLUSTER | LOCAL] TRANSACTIONS

diff --git a/pkg/sql/sem/tree/show.go b/pkg/sql/sem/tree/show.go
@@ -439,6 +439,20 @@ func (node *ShowTables) Format(ctx *FmtCtx) {
 	}
 }
 
+// ShowFunctions represents a SHOW FUNCTIONS statement.
+type ShowFunctions struct {
+	ObjectNamePrefix
+}
+
+// Format implements the NodeFormatter interface.
+func (node *ShowFunctions) Format(ctx *FmtCtx) {
+	ctx.WriteString("SHOW FUNCTIONS")
+	if node.ExplicitSchema {
+		ctx.WriteString(" FROM ")
+		ctx.FormatNode(&node.ObjectNamePrefix)
+	}
+}
+
 // ShowTransactions represents a SHOW TRANSACTIONS statement
 type ShowTransactions struct {
 	All     bool

diff --git a/pkg/sql/sem/tree/stmt.go b/pkg/sql/sem/tree/stmt.go
@@ -1761,6 +1761,15 @@ func (*ShowTables) StatementType() StatementType { return TypeDML }
 // StatementTag returns a short string identifying the type of statement.
 func (*ShowTables) StatementTag() string { return "SHOW TABLES" }
 
+// StatementReturnType implements the Statement interface.
+func (*ShowFunctions) StatementReturnType() StatementReturnType { return Rows }
+
+// StatementType implements the Statement interface.
+func (*ShowFunctions) StatementType() StatementType { return TypeDML }
+
+// StatementTag returns a short string identifying the type of statement.
+func (*ShowFunctions) StatementTag() string { return "SHOW FUNCTIONS" }
+
 // StatementReturnType implements the Statement interface
 func (*ShowTransactions) StatementReturnType() StatementReturnType { return Rows }
 
@@ -2131,6 +2140,7 @@ func (n *ShowEnums) String() string                           { return AsString(
 func (n *ShowFullTableScans) String() string                  { return AsString(n) }
 func (n *ShowCreateFunction) String() string                  { return AsString(n) }
 func (n *ShowCreateExternalConnections) String() string       { return AsString(n) }
+func (n *ShowFunctions) String() string                       { return AsString(n) }
 func (n *ShowGrants) String() string                          { return AsString(n) }
 func (n *ShowHistogram) String() string                       { return AsString(n) }
 func (n *ShowSchedules) String() string                       { return AsString(n) }