Bug #82189 DELETE via the alias of fully qualified table reference fails with ERROR 1046
Submitted: 11 Jul 2016 21:19 Modified: 12 Jul 2016 9:15
Reporter: Daniel Fisher Email Updates:
Status: Verified Impact on me:
None 
Category:MySQL Server: DML Severity:S3 (Non-critical)
Version:5.7.12 MySQL Community Server (GPL), 5.6.31, 5.7.13 OS:Any
Assigned to: CPU Architecture:Any
Tags: ERROR 1046, No database selected

[11 Jul 2016 21:19] Daniel Fisher
Description:
A DELETE FROM ... USING ... JOIN ... WHERE ... statement that targets a table via an alias established in a USING . . . JOIN clause fails with ERROR 1046. This occurs in a session in which no default database has beenestalbished. The equivalent DELETE ... FROM ... JOIN ... WHERE ... produces the same error.

How to repeat:
Create the following databse and tables:

CREATE DATABASE test;

CREATE TABLE test.testA (
    colA INT PRIMARY KEY
);

CREATE TABLE test.testB (
    colB INT PRIMARY KEY,
    colA INT NOT NULL,
    deleteMe INT NOT NULL,
    CONSTRAINT fk_B_A FOREIGN KEY (colA) REFERENCES test.testA (colA)
);

In a fresh session in which no default database has been established, either of these DELETE statements wil produce ERROR 1046: 

DELETE FROM B
USING test.testA A
JOIN test.testB B ON A.colA = B.colB
WHERE B.deleteMe <> 0;
# ERROR 1046

DELETE B
FROM test.testA A
JOIN test.testB B ON A.colA = B.colB
WHERE B.deleteMe <> 0;
# ERROR 1046

The error is no longer thrown if one precedes the DELETE with any proper USE database statement. However, if the default database is dropped, the error will occur again:

CREATE DATABASE FOO;

USE FOO:

DELETE FROM B
USING test.testA A
JOIN test.testB B ON A.colA = B.colB
WHERE B.deleteMe <> 0;
# This works

DROP DATABASE FOO;

DELETE FROM B
USING test.testA A
JOIN test.testB B ON A.colA = B.colB
WHERE B.deleteMe <> 0;
# ERROR 1046
[11 Jul 2016 21:23] Daniel Fisher
In the how to repeat section, the "USE FOO:" line should read "USE FOO;". This mistake occurred in entering the report and not in reproducing the problem. Sorry.
[12 Jul 2016 9:15] Umesh Shastry
Hello Daniel Fisher,

Thank you for the report and test case.
Observed with 5.7.13/5.6.31 builds.

Thanks,
Umesh