Merge #39785

39785: sql: fix has_column_privilege builtin r=yuzefovich a=yuzefovich Previously, has_column_privilege would treat its second argument (when it is an integer) that specifies the column to check the privileges on as an ordinal index of the column, but when a column is dropped from the table, ordinal indices are adjusted, so ordinal_position of information_schema.columns would contain a different from attnum of pg_catalog.pg_attribute number. Now this is fixed. Fixes: #39703. Release note: None Co-authored-by: Yahor Yuzefovich <[email protected]>
cockroachdb · Aug 21, 2019 · 3f1fcb3 · 3f1fcb3
2 parents 93860e6 + 1e2b25b
commit 3f1fcb3
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diff --git a/pkg/sql/logictest/testdata/logic_test/privilege_builtins b/pkg/sql/logictest/testdata/logic_test/privilege_builtins
@@ -951,3 +951,36 @@ query B
 SELECT has_type_privilege('bar', 'text'::REGTYPE::OID, 'USAGE')
 ----
 true
+
+# Regression test for #39703.
+
+statement ok
+DROP TABLE IF EXISTS hcp_test; CREATE TABLE hcp_test (a INT8, b INT8, c INT8)
+
+statement ok
+ALTER TABLE hcp_test DROP COLUMN b
+
+query TI
+SELECT attname, attnum FROM pg_attribute WHERE attrelid = 'hcp_test'::REGCLASS
+----
+a     1
+c     3
+rowid 4
+
+query B
+SELECT has_column_privilege('hcp_test'::REGCLASS, 1, 'SELECT')
+----
+true
+
+statement error column 2 of relation hcp_test does not exist
+SELECT has_column_privilege('hcp_test'::REGCLASS, 2, 'SELECT')
+
+query B
+SELECT has_column_privilege('hcp_test'::REGCLASS, 3, 'SELECT')
+----
+true
+
+query B
+SELECT has_column_privilege('hcp_test'::REGCLASS, 4, 'SELECT')
+----
+true
diff --git a/pkg/sql/sem/builtins/pg_builtins.go b/pkg/sql/sem/builtins/pg_builtins.go
@@ -1031,19 +1031,23 @@ SELECT description
 				colArg := tree.UnwrapDatum(ctx, args[1])
 				switch t := colArg.(type) {
 				case *tree.DString:
-					colPred = "column_name = $1"
+					// When colArg is a string, it specifies the attribute name.
+					colPred = "attname = $1"
 				case *tree.DInt:
-					colPred = "ordinal_position = $1"
+					// When colArg is an integer, it specifies the attribute number.
+					colPred = "attnum = $1"
 				default:
-					log.Fatalf(ctx.Ctx(), "expected arg type %T", t)
+					log.Fatalf(ctx.Ctx(), "unexpected arg type %T", t)
 				}
 
 				if r, err := ctx.InternalExecutor.QueryRow(
 					ctx.Ctx(), "has-column-privilege",
 					ctx.Txn,
 					fmt.Sprintf(`
-					SELECT column_name FROM information_schema.columns
-					WHERE %s AND %s`, pred, colPred), colArg); err != nil {
+					SELECT attname FROM pg_attribute
+					 WHERE attrelid = '%s.%s.%s'::REGCLASS AND %s`,
+						tn.CatalogName, tn.SchemaName, tn.TableName, colPred), colArg,
+				); err != nil {
 					return nil, err
 				} else if r == nil {
 					return nil, pgerror.Newf(pgcode.UndefinedColumn,