MySQL Bugs: #79873: DROP TRIGGER after RENAME TABLE results in Error Code 1146: table doesn't exist.

Bug #79873	DROP TRIGGER after RENAME TABLE results in Error Code 1146: table doesn't exist.
Submitted:	7 Jan 2016 14:11	Modified:	3 Oct 2016 18:11
Reporter:	Michael Vaughan	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: DML	Severity:	S3 (Non-critical)
Version:	5.7.10	OS:	MacOS (10.11.2)
Assigned to:		CPU Architecture:	Any

Description:
If a table that has an existing trigger is renamed via a RENAME TABLE statement, attempting to drop the existing trigger will result in a "Table doesn't exist" error. This bug appears to result in triggers that can't be dropped.

How to repeat:
CREATE SCHEMA testschema DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci ;

USE testschema;

CREATE TABLE Test(
  id  int not null primary key auto_increment,
  name varchar(255)
);

delimiter //
CREATE TRIGGER TEST_TRIGGER
BEFORE INSERT ON Test
FOR EACH ROW 
BEGIN
   SET NEW.name = CONCAT(NEW.name, '_X');
END//
delimiter ;

RENAME TABLE Test TO TestRenamed;

DROP TRIGGER TEST_TRIGGER;

Executing the script above will give the following response:

"Error Code: 1146. Table 'testschema.TestRenamed' doesn't exist"

However executing the following query returns a row showing the table was successfully renamed.

SELECT * from information_schema.TABLES WHERE TABLE_SCHEMA = 'testschema' AND TABLE_NAME = 'TestRenamed';

Suggested fix:
The expected behavior would be to drop the trigger. The current functionality appears to result in a trigger that can't be deleted.

This bug appears to be specific to OSX. The bug has been verified on the following environments:
- OSX 10.11.2/MySQL 5.7.10
- OSX 10.11.1/MySQL 5.6.19

The test script has worked as desired in the following environments:
- Linux Mint 17.2 Cinnamon 64 bit/MySQL 5.5.46-0ubuntu0.14.04.2.

On Windows:

C:\dbs>c:\dbs\5.7\bin\mysql -uroot -p --port=3570 --prompt="mysql 5.7 > "
Enter password: ******
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 7
Server version: 5.7.11 Source distribution PULL: 2015-DEC-27

Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql 5.7 > CREATE SCHEMA testschema DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci ;
Query OK, 1 row affected (0.00 sec)

mysql 5.7 >
mysql 5.7 > USE testschema;
Database changed
mysql 5.7 >
mysql 5.7 > CREATE TABLE Test(
    ->   id  int not null primary key auto_increment,
    ->   name varchar(255)
    -> );
Query OK, 0 rows affected (0.03 sec)

mysql 5.7 >
mysql 5.7 > delimiter //
mysql 5.7 > CREATE TRIGGER TEST_TRIGGER
    -> BEFORE INSERT ON Test
    -> FOR EACH ROW
    -> BEGIN
    ->    SET NEW.name = CONCAT(NEW.name, '_X');
    -> END//
Query OK, 0 rows affected (0.02 sec)

mysql 5.7 > delimiter ;
mysql 5.7 >
mysql 5.7 > RENAME TABLE Test TO TestRenamed;
Query OK, 0 rows affected (0.03 sec)

mysql 5.7 > DROP TRIGGER TEST_TRIGGER;
Query OK, 0 rows affected (0.02 sec)

Repeatable with 5.7.9. I will test 5.7.10 too:

Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.7.9 MySQL Community Server (GPL)

Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> CREATE SCHEMA testschema DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci ;
Query OK, 1 row affected (0.00 sec)

mysql>
mysql> USE testschema;
Database changed
mysql>
mysql> CREATE TABLE Test(
    ->   id  int not null primary key auto_increment,
    ->   name varchar(255)
    -> );
Query OK, 0 rows affected (0.06 sec)

mysql>
mysql> delimiter //
mysql> CREATE TRIGGER TEST_TRIGGER
    -> BEFORE INSERT ON Test
    -> FOR EACH ROW
    -> BEGIN
    ->    SET NEW.name = CONCAT(NEW.name, '_X');
    -> END//
Query OK, 0 rows affected (0.34 sec)

mysql> delimiter ;
mysql>
mysql> RENAME TABLE Test TO TestRenamed;
Query OK, 0 rows affected (0.29 sec)

mysql>
mysql> DROP TRIGGER TEST_TRIGGER;
ERROR 1146 (42S02): Table 'testschema.TestRenamed' doesn't exist
mysql> show variables like "%versio%";
+-------------------------+------------------------------+
| Variable_name           | Value                        |
+-------------------------+------------------------------+
| innodb_version          | 5.7.9                        |
| protocol_version        | 10                           |
| slave_type_conversions  |                              |
| version                 | 5.7.9                        |
| version_comment         | MySQL Community Server (GPL) |
| version_compile_machine | x86_64                       |
| version_compile_os      | osx10.9                      |
+-------------------------+------------------------------+
7 rows in set (0.00 sec)

Thank you for the bug report.

miguel:~ miguel$ mysql -uroot -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 34
Server version: 5.7.10 MySQL Community Server (GPL)

Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> CREATE SCHEMA testschema DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci ;
Query OK, 1 row affected (0.00 sec)

mysql>
mysql> USE testschema;
Database changed
mysql>
mysql> CREATE TABLE Test(
    ->   id  int not null primary key auto_increment,
    ->   name varchar(255)
    -> );
Query OK, 0 rows affected (0.08 sec)

mysql>
mysql> delimiter //
mysql> CREATE TRIGGER TEST_TRIGGER
    -> BEFORE INSERT ON Test
    -> FOR EACH ROW
    -> BEGIN
    ->    SET NEW.name = CONCAT(NEW.name, '_X');
    -> END//
Query OK, 0 rows affected (0.38 sec)

mysql> delimiter ;
mysql>
mysql> RENAME TABLE Test TO TestRenamed;
Query OK, 0 rows affected (0.32 sec)

mysql>
mysql> DROP TRIGGER TEST_TRIGGER;
ERROR 1146 (42S02): Table 'testschema.TestRenamed' doesn't exist
mysql> SHOW VARIABLES LIKE "%version%";
+-------------------------+------------------------------+
| Variable_name           | Value                        |
+-------------------------+------------------------------+
| innodb_version          | 5.7.10                       |
| protocol_version        | 10                           |
| slave_type_conversions  |                              |
| tls_version             | TLSv1,TLSv1.1                |
| version                 | 5.7.10                       |
| version_comment         | MySQL Community Server (GPL) |
| version_compile_machine | x86_64                       |
| version_compile_os      | osx10.9                      |
+-------------------------+------------------------------+
8 rows in set (0.03 sec)

Posted by developer:
 
Noted in 5.7.17, 8.0.1 changelogs.

On macOS, if a table with an associated trigger was renamed to a new
name containing both lowercase and uppercase uppercase characters, 
DROP TRIGGER for the trigger resulted in an ER_NO_SUCH_TABLE error
for the table.