Syntax error when creating procedure in mysql - mysql

Question

I have this query.
SELECT distinct c.reportingDate, c.clientId
FROM clients AS c
WHERE NOT EXISTS
( SELECT 1
FROM accounts_europe AS e
WHERE e.reportingDate = c.reportingDate
AND e.clientId = c.clientId
union
SELECT 1 -- line A. unexpected select error
FROM accounts_usa AS u
WHERE u.reportingDate = c.reportingDate
AND u.clientId = c.clientId
) ;
when executing it at mysql workbench it displays a syntax error which says "unexpected select" at line A.
However, since the query is right, when I execute it, it indeed executes and returns the correct results.
When I try to create a procedure that contains the exact same thing, it cannot be compiled. The source code is this:
CREATE PROCEDURE `proc_sample`()
BEGIN
SELECT distinct c.reportingDate, c.clientId
FROM clients AS c
WHERE NOT EXISTS
( SELECT 1
FROM accounts_europe AS e
WHERE e.reportingDate = c.reportingDate
AND e.clientId = c.clientId
union
SELECT 1 -- line A. unexpected select error
FROM accounts_usa AS u
WHERE u.reportingDate = c.reportingDate
AND u.clientId = c.clientId
) ;
END
The message displayed is "The object's DDL statement contains syntax errors."
Is it something I am doing wrong about this or is it a bug of the mysql workbench?

Answer 1

This error comes up because of a MySQL grammar bug* that has been fixed meanwhile. Try the latest Workbench version instead (currently WB 8.0.11 RC, see "Development Releases" on the download page). That should work for you.
(*) MySQL Workbench uses ANTLR4 for parsing SQL code. That requires a MySQL grammar to generate the parser.

Answer 2

Your query is correct syntactically. It's maybe a workbench's bug. Coming to Stored Procedure, you should be able to create it with that query. Try creating SP using below query. In my case, I am able to create SP using this. Copy this query open a new query editor in the workbench and paste it there, select all and press Ctrl + Shift + Enter
USE `YOUR_DB`;
DROP procedure IF EXISTS `proc_sample`;
DELIMITER $$
USE `YOUR_DB`$$
CREATE DEFINER=`admin`#`%` PROCEDURE `proc_sample`()
BEGIN
SELECT distinct c.reportingDate, c.clientId
FROM clients AS c
WHERE NOT EXISTS
( SELECT 1
FROM accounts_europe AS e
WHERE e.reportingDate = c.reportingDate
AND e.clientId = c.clientId
union
SELECT 1
FROM accounts_usa AS u
WHERE u.reportingDate = c.reportingDate
AND u.clientId = c.clientId
) ;
END$$
DELIMITER ;