MySQL Bugs: #94586: SELECT WHERE valid without FROM

Bug #94586	SELECT WHERE valid without FROM
Submitted:	7 Mar 2019 8:02	Modified:	7 Mar 2019 14:28
Reporter:	James Smith	Email Updates:
Status:	Not a Bug	Impact on me:	None
Category:	MySQL Server	Severity:	S3 (Non-critical)
Version:	5.7.25	OS:	MacOS (macOS 10.14.x Mojave x86_64)
Assigned to:		CPU Architecture:	Any
Tags:	WBBugReporter

Description:
Supposed I have a table SomeTable with a single INT column.

This query works fine:

```
INSERT INTO SomeTable
SELECT 1 WHERE true
UNION
SELECT 2 FROM SomeTable WHERE true
```
https://i.imgur.com/uTr2ZR9.gif

But this gives a syntax error:

```
INSERT INTO SomeTable
(SELECT 1 WHERE true) 
UNION
(SELECT 2 WHERE true) 
```

> Error Code: 1064. You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'WHERE true)' at line 4

How to repeat:
Create SomeTable with a single INT column and run the 2 queries above.

Suggested fix:
The above queries should either be both valid or both invalid.

Hi,

Thank you for your report. However, this is not a bug.

This is SQL not C or Java. 

Hence, you can not use:

WHERE true

as it makes no sense.

You can use :

WHERE 1=1

or with some BOOLEAN COLUMN:

WHERE Some_Boolean_Column IS TRUE.