MDEV-12325 Unexpected data type and truncation when using CTE

When creating a recursive CTE, the column types are taken from the non recursive part of the CTE (this is according to the SQL standard). This patch adds code to abort the CTE if the calculated values in the recursive part does not fit in the fields in the created temporary table. The new code only affects recursive CTE, so it should not cause any notable problems for old applications. Other things: - Fixed that we get correct row numbers for warnings generated with WITH RECURSIVE Reviewer: Alexander Barkov <bar@mariadb.com>
MariaDB · Aug 8, 2022 · a5a9fcd · a5a9fcd
1 parent 43c7f6a
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diff --git a/mysql-test/main/cte_recursive.result b/mysql-test/main/cte_recursive.result
@@ -4873,4 +4873,149 @@ a
 0
 NULL
 DROP TABLE t1;
+#
+# MDEV-12325 Unexpected data type and truncation when using CTE
+#
+CREATE TABLE t1
+(
+id INT, mid INT, name TEXT
+);
+INSERT INTO t1 VALUES (0,NULL,'Name'),(1,0,'Name1'),(2,0,'Name2'),(11,1,'Name11'),(12,1,'Name12');
+WITH RECURSIVE
+cteReports (level, id, mid, name) AS
+(
+SELECT 1, id, mid, name FROM t1 WHERE mid IS NULL
+UNION ALL
+SELECT r.level + 1, e.id, e.mid + 1000000000000, e.name FROM t1 e
+INNER JOIN cteReports r ON e.mid = r.id
+)
+SELECT
+level, id, mid, name,
+(SELECT name FROM t1 WHERE id= cteReports.mid) AS mname
+FROM cteReports ORDER BY level, mid;
+ERROR 22003: Out of range value for column 'mid' at row 2
+create table t2 as WITH RECURSIVE
+cteReports (level, id, mid, name) AS
+(
+SELECT 1, id, mid, name FROM t1 WHERE mid IS NULL
+UNION ALL
+SELECT r.level + 1, e.id, e.mid + 1000000000000, e.name FROM t1 e
+INNER JOIN cteReports r ON e.mid = r.id
+)
+SELECT
+level, id, mid, name,
+(SELECT name FROM t1 WHERE id= cteReports.mid) AS mname
+FROM cteReports ORDER BY level, mid;;
+ERROR 22003: Out of range value for column 'mid' at row 2
+create table t2 ignore as WITH RECURSIVE
+cteReports (level, id, mid, name) AS
+(
+SELECT 1, id, mid, name FROM t1 WHERE mid IS NULL
+UNION ALL
+SELECT r.level + 1, e.id, e.mid + 1000000000000, e.name FROM t1 e
+INNER JOIN cteReports r ON e.mid = r.id
+)
+SELECT
+level, id, mid, name,
+(SELECT name FROM t1 WHERE id= cteReports.mid) AS mname
+FROM cteReports ORDER BY level, mid;;
+Warnings:
+Warning	1264	Out of range value for column 'mid' at row 2
+Warning	1264	Out of range value for column 'mid' at row 3
+Warning	1264	Out of range value for column 'mid' at row 4
+Warning	1264	Out of range value for column 'mid' at row 5
+show create table t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `level` int(1) DEFAULT NULL,
+  `id` int(11) DEFAULT NULL,
+  `mid` int(11) DEFAULT NULL,
+  `name` text DEFAULT NULL,
+  `mname` text DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+insert into t2 WITH RECURSIVE
+cteReports (level, id, mid, name) AS
+(
+SELECT 1, id, mid, name FROM t1 WHERE mid IS NULL
+UNION ALL
+SELECT r.level + 1, e.id, e.mid + 1000000000000, e.name FROM t1 e
+INNER JOIN cteReports r ON e.mid = r.id
+)
+SELECT
+level, id, mid, name,
+(SELECT name FROM t1 WHERE id= cteReports.mid) AS mname
+FROM cteReports ORDER BY level, mid;;
+ERROR 22003: Out of range value for column 'mid' at row 2
+insert ignore into t2 WITH RECURSIVE
+cteReports (level, id, mid, name) AS
+(
+SELECT 1, id, mid, name FROM t1 WHERE mid IS NULL
+UNION ALL
+SELECT r.level + 1, e.id, e.mid + 1000000000000, e.name FROM t1 e
+INNER JOIN cteReports r ON e.mid = r.id
+)
+SELECT
+level, id, mid, name,
+(SELECT name FROM t1 WHERE id= cteReports.mid) AS mname
+FROM cteReports ORDER BY level, mid;;
+Warnings:
+Warning	1264	Out of range value for column 'mid' at row 2
+Warning	1264	Out of range value for column 'mid' at row 3
+Warning	1264	Out of range value for column 'mid' at row 4
+Warning	1264	Out of range value for column 'mid' at row 5
+drop table t2;
+set @@sql_mode="";
+WITH RECURSIVE
+cteReports (level, id, mid, name) AS
+(
+SELECT 1, id, mid, name FROM t1 WHERE mid IS NULL
+UNION ALL
+SELECT r.level + 1, e.id, e.mid + 1000000000000, e.name FROM t1 e
+INNER JOIN cteReports r ON e.mid = r.id
+)
+SELECT
+level, id, mid, name,
+(SELECT name FROM t1 WHERE id= cteReports.mid) AS mname
+FROM cteReports ORDER BY level, mid;
+level	id	mid	name	mname
+1	0	NULL	Name	NULL
+2	1	2147483647	Name1	NULL
+2	2	2147483647	Name2	NULL
+3	11	2147483647	Name11	NULL
+3	12	2147483647	Name12	NULL
+Warnings:
+Warning	1264	Out of range value for column 'mid' at row 2
+Warning	1264	Out of range value for column 'mid' at row 3
+Warning	1264	Out of range value for column 'mid' at row 4
+Warning	1264	Out of range value for column 'mid' at row 5
+create table t2 as WITH RECURSIVE
+cteReports (level, id, mid, name) AS
+(
+SELECT 1, id, mid, name FROM t1 WHERE mid IS NULL
+UNION ALL
+SELECT r.level + 1, e.id, e.mid + 1000000000000, e.name FROM t1 e
+INNER JOIN cteReports r ON e.mid = r.id
+)
+SELECT
+level, id, mid, name,
+(SELECT name FROM t1 WHERE id= cteReports.mid) AS mname
+FROM cteReports ORDER BY level, mid;;
+Warnings:
+Warning	1264	Out of range value for column 'mid' at row 2
+Warning	1264	Out of range value for column 'mid' at row 3
+Warning	1264	Out of range value for column 'mid' at row 4
+Warning	1264	Out of range value for column 'mid' at row 5
+show create table t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `level` int(1) DEFAULT NULL,
+  `id` int(11) DEFAULT NULL,
+  `mid` int(11) DEFAULT NULL,
+  `name` text DEFAULT NULL,
+  `mname` text DEFAULT NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+set @@sql_mode=default;
+drop table t1,t2;
+#
 # End of 10.3 tests
+#
diff --git a/mysql-test/main/cte_recursive.test b/mysql-test/main/cte_recursive.test
@@ -3165,4 +3165,47 @@ SELECT * FROM cte;
 
 DROP TABLE t1;
 
+--echo #
+--echo # MDEV-12325 Unexpected data type and truncation when using CTE
+--echo #
+
+CREATE TABLE t1
+(
+  id INT, mid INT, name TEXT
+);
+INSERT INTO t1 VALUES (0,NULL,'Name'),(1,0,'Name1'),(2,0,'Name2'),(11,1,'Name11'),(12,1,'Name12');
+
+let $query=
+WITH RECURSIVE
+cteReports (level, id, mid, name) AS
+(
+  SELECT 1, id, mid, name FROM t1 WHERE mid IS NULL
+  UNION ALL
+  SELECT r.level + 1, e.id, e.mid + 1000000000000, e.name FROM t1 e
+  INNER JOIN cteReports r ON e.mid = r.id
+)
+SELECT
+  level, id, mid, name,
+  (SELECT name FROM t1 WHERE id= cteReports.mid) AS mname
+FROM cteReports ORDER BY level, mid;
+
+--error ER_WARN_DATA_OUT_OF_RANGE
+--eval $query
+--error ER_WARN_DATA_OUT_OF_RANGE
+--eval create table t2 as $query;
+--eval create table t2 ignore as $query;
+show create table t2;
+--error ER_WARN_DATA_OUT_OF_RANGE
+--eval insert into t2 $query;
+--eval insert ignore into t2 $query;
+drop table t2;
+set @@sql_mode="";
+--eval $query
+--eval create table t2 as $query;
+show create table t2;
+set @@sql_mode=default;
+drop table t1,t2;
+
+--echo #
 --echo # End of 10.3 tests
+--echo #
diff --git a/sql/sql_class.h b/sql/sql_class.h
@@ -5691,10 +5691,12 @@ class select_union_recursive :public select_unit
     or for the unit specifying a CTE that mutually recursive with this CTE.
   */
   uint cleanup_count;
+  long row_counter;
 
   select_union_recursive(THD *thd_arg):
     select_unit(thd_arg),
-    incr_table(0), first_rec_table_to_update(0), cleanup_count(0)
+      incr_table(0), first_rec_table_to_update(0), cleanup_count(0),
+      row_counter(0)
   { incr_table_param.init(); };
 
   int send_data(List<Item> &items);

diff --git a/sql/sql_error.h b/sql/sql_error.h
@@ -722,6 +722,13 @@ class Warning_info
   /** Reset the current row counter. Start counting from the first row. */
   void reset_current_row_for_warning() { m_current_row_for_warning= 1; }
 
+  ulong set_current_row_for_warning(ulong row)
+  {
+    ulong old_row= m_current_row_for_warning;
+    m_current_row_for_warning= row;
+    return old_row;
+  }
+
   /** Return the current counter value. */
   ulong current_row_for_warning() const { return m_current_row_for_warning; }
 
@@ -1099,6 +1106,9 @@ class Diagnostics_area: public Sql_state_errno,
   void opt_clear_warning_info(ulonglong query_id)
   { get_warning_info()->opt_clear(query_id); }
 
+  long set_current_row_for_warning(long row)
+  { return get_warning_info()->set_current_row_for_warning(row); }
+
   ulong current_row_for_warning() const
   { return get_warning_info()->current_row_for_warning(); }
 

diff --git a/sql/sql_union.cc b/sql/sql_union.cc
@@ -297,7 +297,27 @@ bool select_unit::send_eof()
 
 int select_union_recursive::send_data(List<Item> &values)
 {
-  int rc= select_unit::send_data(values);
+
+  int rc;
+  bool save_abort_on_warning= thd->abort_on_warning;
+  enum_check_fields save_count_cuted_fields= thd->count_cuted_fields;
+  long save_counter;
+
+  /*
+    For recursive CTE's give warnings for wrong field info
+    However, we don't do that for CREATE TABLE ... SELECT or INSERT ... SELECT
+    as the upper level code for these handles setting of abort_on_warning
+    depending on if 'IGNORE' is used.
+  */
+  if (thd->lex->sql_command != SQLCOM_CREATE_TABLE &&
+      thd->lex->sql_command != SQLCOM_INSERT_SELECT)
+    thd->abort_on_warning= thd->is_strict_mode();
+  thd->count_cuted_fields= CHECK_FIELD_WARN;
+  save_counter= thd->get_stmt_da()->set_current_row_for_warning(++row_counter);
+  rc= select_unit::send_data(values);
+  thd->get_stmt_da()->set_current_row_for_warning(save_counter);
+  thd->count_cuted_fields= save_count_cuted_fields;
+  thd->abort_on_warning= save_abort_on_warning;
 
   if (rc == 0 &&
       write_err != HA_ERR_FOUND_DUPP_KEY &&
@@ -476,6 +496,7 @@ void select_union_recursive::cleanup()
     thd->rec_tables= tab;
     tbl->derived_result= 0;
   }
+  row_counter= 0;
 }
 
 

diff --git a/sql/sql_yacc.yy b/sql/sql_yacc.yy
@@ -15373,7 +15373,6 @@ with_clause:
                MYSQL_YYABORT;
              Lex->derived_tables|= DERIVED_WITH;
              Lex->with_cte_resolution= true;
-             Lex->with_cte_resolution= true;
              Lex->curr_with_clause= with_clause;
              with_clause->add_to_list(Lex->with_clauses_list_last_next);
           }