BUG#22037930: INSERT IGNORE FAILS TO IGNORE FOREIGN KEY

              CONSTRAINT.

Analysis
=======

INSERT and UPDATE operations using the IGNORE keyword which
causes FOREIGN KEY constraint violations reports an error
despite using the IGNORE keyword.

Foreign key violation errors were not ignored and reported
as errors instead of warnings even when IGNORE was set.

Fix
===
Added code to ignore the foreign key violation errors and
report them as warnings when the IGNORE keyword is used.

mysql-test/r/insert.result

@@ -686,3 +686,41 @@ ERROR 42000: Column 'a' specified twice
 INSERT IGNORE t1 (a, a) SELECT 1,1 UNION SELECT 2,2;
 ERROR 42000: Column 'a' specified twice
 DROP TABLE t1;
+#
+# BUG#22037930: INSERT IGNORE FAILS TO IGNORE
+#               FOREIGN KEY CONSTRAINT
+# Setup.
+CREATE TABLE t1 (fld1 INT PRIMARY KEY) ENGINE=INNODB;
+CREATE TABLE t2 (fld2 INT, FOREIGN KEY (fld2) REFERENCES t1 (fld1))
+ENGINE=INNODB;
+INSERT INTO t1 VALUES(0);
+INSERT INTO t2 VALUES(0);
+# Without fix, an error is reported.
+INSERT IGNORE INTO t2 VALUES(1);
+Warnings:
+Warning	1452	`test`.`t2`, CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`fld2`) REFERENCES `t1` (`fld1`)
+UPDATE IGNORE t2 SET fld2=20 WHERE fld2=0;
+Warnings:
+Warning	1452	`test`.`t2`, CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`fld2`) REFERENCES `t1` (`fld1`)
+UPDATE IGNORE t1 SET fld1=20 WHERE fld1=0;
+Warnings:
+Warning	1451	`test`.`t2`, CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`fld2`) REFERENCES `t1` (`fld1`)
+# Test for multi update.
+UPDATE IGNORE t1, t2 SET t2.fld2= t2.fld2 + 3;
+Warnings:
+Warning	1452	`test`.`t2`, CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`fld2`) REFERENCES `t1` (`fld1`)
+UPDATE IGNORE t1, t2 SET t1.fld1= t1.fld1 + 3;
+Warnings:
+Warning	1451	`test`.`t2`, CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`fld2`) REFERENCES `t1` (`fld1`)
+# Reports an error since IGNORE is not used.
+INSERT INTO t2 VALUES(1);
+ERROR 23000: Cannot add or update a child row: a foreign key constraint fails (`test`.`t2`, CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`fld2`) REFERENCES `t1` (`fld1`))
+UPDATE t2 SET fld2=20 WHERE fld2=0;
+ERROR 23000: Cannot add or update a child row: a foreign key constraint fails (`test`.`t2`, CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`fld2`) REFERENCES `t1` (`fld1`))
+UPDATE t1 SET fld1=20 WHERE fld1=0;
+ERROR 23000: Cannot delete or update a parent row: a foreign key constraint fails (`test`.`t2`, CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`fld2`) REFERENCES `t1` (`fld1`))
+UPDATE t1, t2 SET t2.fld2= t2.fld2 + 3;
+ERROR 23000: Cannot add or update a child row: a foreign key constraint fails (`test`.`t2`, CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`fld2`) REFERENCES `t1` (`fld1`))
+UPDATE t1, t2 SET t1.fld1= t1.fld1 + 3;
+ERROR 23000: Cannot delete or update a parent row: a foreign key constraint fails (`test`.`t2`, CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`fld2`) REFERENCES `t1` (`fld1`))
+DROP TABLE t2, t1;

mysql-test/t/insert.test

@@ -550,3 +550,44 @@ INSERT IGNORE t1 (a, a) SELECT 1,1;
 INSERT IGNORE t1 (a, a) SELECT 1,1 UNION SELECT 2,2;
 
 DROP TABLE t1;
+
+
+--echo #
+--echo # BUG#22037930: INSERT IGNORE FAILS TO IGNORE
+--echo #               FOREIGN KEY CONSTRAINT
+
+--echo # Setup.
+CREATE TABLE t1 (fld1 INT PRIMARY KEY) ENGINE=INNODB;
+CREATE TABLE t2 (fld2 INT, FOREIGN KEY (fld2) REFERENCES t1 (fld1))
+ENGINE=INNODB;
+INSERT INTO t1 VALUES(0);
+INSERT INTO t2 VALUES(0);
+
+--echo # Without fix, an error is reported.
+--enable_warnings
+INSERT IGNORE INTO t2 VALUES(1);
+UPDATE IGNORE t2 SET fld2=20 WHERE fld2=0;
+UPDATE IGNORE t1 SET fld1=20 WHERE fld1=0;
+
+--echo # Test for multi update.
+UPDATE IGNORE t1, t2 SET t2.fld2= t2.fld2 + 3;
+UPDATE IGNORE t1, t2 SET t1.fld1= t1.fld1 + 3;
+--disable_warnings
+
+--echo # Reports an error since IGNORE is not used.
+--error ER_NO_REFERENCED_ROW_2
+INSERT INTO t2 VALUES(1);
+
+--error ER_NO_REFERENCED_ROW_2
+UPDATE t2 SET fld2=20 WHERE fld2=0;
+
+--error ER_ROW_IS_REFERENCED_2
+UPDATE t1 SET fld1=20 WHERE fld1=0;
+
+--error ER_NO_REFERENCED_ROW_2
+UPDATE t1, t2 SET t2.fld2= t2.fld2 + 3;
+
+--error ER_ROW_IS_REFERENCED_2
+UPDATE t1, t2 SET t1.fld1= t1.fld1 + 3;
+
+DROP TABLE t2, t1;

sql/handler.cc

-/* Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
+/* Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -5452,3 +5452,28 @@ fl_create_iterator(enum handler_iterator_type type,
   }
 }
 #endif /*TRANS_LOG_MGM_EXAMPLE_CODE*/
+
+
+/**
+   Report a warning for FK constraint violation.
+
+   @param  thd     Thread handle.
+   @param  table   table on which the operation is performed.
+   @param  error   handler error number.
+*/
+void warn_fk_constraint_violation(THD *thd,TABLE *table, int error)
+{
+  String str;
+  switch(error) {
+  case HA_ERR_ROW_IS_REFERENCED:
+    table->file->get_error_message(error, &str);
+    push_warning(thd, MYSQL_ERROR::WARN_LEVEL_WARN,
+                 ER_ROW_IS_REFERENCED_2, str.c_ptr_safe());
+    break;
+  case HA_ERR_NO_REFERENCED_ROW:
+    table->file->get_error_message(error, &str);
+    push_warning(thd, MYSQL_ERROR::WARN_LEVEL_WARN,
+                 ER_NO_REFERENCED_ROW_2, str.c_ptr_safe());
+    break;
+  }
+}

sql/handler.h

@@ -2,7 +2,7 @@
 #define HANDLER_INCLUDED
 
 /*
-   Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
+   Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License
@@ -303,6 +303,7 @@
 /* Flags for method is_fatal_error */
 #define HA_CHECK_DUP_KEY 1
 #define HA_CHECK_DUP_UNIQUE 2
+#define HA_CHECK_FK_ERROR 4
 #define HA_CHECK_DUP (HA_CHECK_DUP_KEY + HA_CHECK_DUP_UNIQUE)
 
 enum legacy_db_type
@@ -1485,7 +1486,10 @@ class handler :public Sql_alloc
     if (!error ||
         ((flags & HA_CHECK_DUP_KEY) &&
          (error == HA_ERR_FOUND_DUPP_KEY ||
-          error == HA_ERR_FOUND_DUPP_UNIQUE)))
+          error == HA_ERR_FOUND_DUPP_UNIQUE)) ||
+        ((flags & HA_CHECK_FK_ERROR) &&
+         (error == HA_ERR_ROW_IS_REFERENCED ||
+          error == HA_ERR_NO_REFERENCED_ROW)))
       return FALSE;
     return TRUE;
   }
@@ -2362,4 +2366,6 @@ inline const char *table_case_name(HA_CREATE_INFO *info, const char *name)
   return ((lower_case_table_names == 2 && info->alias) ? info->alias : name);
 }
 
+void warn_fk_constraint_violation(THD *thd, TABLE *table, int error);
+
 #endif /* HANDLER_INCLUDED */

sql/sql_insert.cc

 /*
-   Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.
+   Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -1522,7 +1522,7 @@ int write_record(THD *thd, TABLE *table,COPY_INFO *info)
       else
         table->file->insert_id_for_cur_row= insert_id_for_cur_row;
       bool is_duplicate_key_error;
-      if (table->file->is_fatal_error(error, HA_CHECK_DUP))
+      if (table->file->is_fatal_error(error, HA_CHECK_DUP | HA_CHECK_FK_ERROR))
 	goto err;
       is_duplicate_key_error= table->file->is_fatal_error(error, 0);
       if (!is_duplicate_key_error)
@@ -1620,7 +1620,8 @@ int write_record(THD *thd, TABLE *table,COPY_INFO *info)
               error != HA_ERR_RECORD_IS_THE_SAME)
           {
             if (info->ignore &&
-                !table->file->is_fatal_error(error, HA_CHECK_DUP_KEY))
+                !table->file->is_fatal_error(error, HA_CHECK_DUP_KEY |
+                                                    HA_CHECK_FK_ERROR))
             {
               goto ok_or_after_trg_err;
             }
@@ -1733,7 +1734,7 @@ int write_record(THD *thd, TABLE *table,COPY_INFO *info)
   {
     DEBUG_SYNC(thd, "write_row_noreplace");
     if (!info->ignore ||
-        table->file->is_fatal_error(error, HA_CHECK_DUP))
+        table->file->is_fatal_error(error, HA_CHECK_DUP | HA_CHECK_FK_ERROR))
       goto err;
     table->file->restore_auto_increment(prev_insert_id);
     goto ok_or_after_trg_err;
@@ -1751,6 +1752,9 @@ int write_record(THD *thd, TABLE *table,COPY_INFO *info)
     my_safe_afree(key,table->s->max_unique_length,MAX_KEY_LENGTH);
   if (!table->file->has_transactions())
     thd->transaction.stmt.modified_non_trans_table= TRUE;
+  if (info->ignore &&
+      !table->file->is_fatal_error(error, HA_CHECK_FK_ERROR))
+    warn_fk_constraint_violation(thd, table, error);
   DBUG_RETURN(trg_error);
 
 err:

sql/sql_update.cc

-/* Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
+/* Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -735,7 +735,8 @@ int mysql_update(THD *thd,
             error= 0;
 	}
  	else if (!ignore ||
-                 table->file->is_fatal_error(error, HA_CHECK_DUP_KEY))
+                 table->file->is_fatal_error(error, HA_CHECK_DUP_KEY |
+                                                    HA_CHECK_FK_ERROR))
 	{
           /*
             If (ignore && error is ignorable) we don't have to
@@ -743,7 +744,8 @@ int mysql_update(THD *thd,
           */
           myf flags= 0;
 
-          if (table->file->is_fatal_error(error, HA_CHECK_DUP_KEY))
+          if (table->file->is_fatal_error(error, HA_CHECK_DUP_KEY |
+                                                 HA_CHECK_FK_ERROR))
             flags|= ME_FATALERROR; /* Other handler errors are fatal */
 
           prepare_record_for_error_message(error, table);
@@ -751,6 +753,9 @@ int mysql_update(THD *thd,
 	  error= 1;
 	  break;
 	}
+        else if (ignore && !table->file->is_fatal_error(error,
+                                                        HA_CHECK_FK_ERROR))
+          warn_fk_constraint_violation(thd, table, error);
       }
 
       if (table->triggers &&
@@ -1883,7 +1888,8 @@ bool multi_update::send_data(List<Item> &not_used_values)
         {
           updated--;
           if (!ignore ||
-              table->file->is_fatal_error(error, HA_CHECK_DUP_KEY))
+              table->file->is_fatal_error(error, HA_CHECK_DUP_KEY |
+                                                 HA_CHECK_FK_ERROR))
           {
             /*
               If (ignore && error == is ignorable) we don't have to
@@ -1891,13 +1897,17 @@ bool multi_update::send_data(List<Item> &not_used_values)
             */
             myf flags= 0;
 
-            if (table->file->is_fatal_error(error, HA_CHECK_DUP_KEY))
+            if (table->file->is_fatal_error(error, HA_CHECK_DUP_KEY |
+                                                   HA_CHECK_FK_ERROR))
               flags|= ME_FATALERROR; /* Other handler errors are fatal */
 
             prepare_record_for_error_message(error, table);
             table->file->print_error(error,MYF(flags));
             DBUG_RETURN(1);
           }
+          else if (ignore && !table->file->is_fatal_error(error,
+                                                          HA_CHECK_FK_ERROR))
+            warn_fk_constraint_violation(thd, table, error);
         }
         else
         {
@@ -2138,8 +2148,12 @@ int multi_update::do_updates()
             local_error != HA_ERR_RECORD_IS_THE_SAME)
 	{
 	  if (!ignore ||
-              table->file->is_fatal_error(local_error, HA_CHECK_DUP_KEY))
+              table->file->is_fatal_error(local_error, HA_CHECK_DUP_KEY |
+                                                       HA_CHECK_FK_ERROR))
 	    goto err;
+          else if (ignore && !table->file->is_fatal_error(local_error,
+                                                          HA_CHECK_FK_ERROR))
+            warn_fk_constraint_violation(thd, table, local_error);
 	}
         if (local_error != HA_ERR_RECORD_IS_THE_SAME)
           updated++;