Bug #116997 select where 1=? 问题

• Submitted: 17 Dec 2024 10:15
• Modified: 17 Dec 2024 11:11
• Reporter: fanshuo meng
• Status: Not a Bug
• Category: MySQL Server: DML
• Severity: S3 (Non-critical)
• Version: 8.0.36
• OS: Any
• CPU Architecture: Any
• Tags: SELECT

[17 Dec 2024 10:15] fanshuo meng

Description:
SELECT * FROM your_table WHERE 1='1agavagag'

This sql can query data.

How to repeat:

Where 1='1 random string no number'

[17 Dec 2024 11:11] MySQL Verification Team

Hi Mr. meng,

Thank you for your bug report.

However, this is not a bug.

Your query:

SELECT * FROM your_table WHERE 1='1agavagag'

returns data, because when you compare an integer to a string, MySQL uses floating point number as a common denominator.

As 1 is always equal to 1, you will get a result set. Hence , this is expected behaviour.

But if you look at the warning, that this query returns, you will see why are results returned:

mysql> show warnings;
+---------+------+-----------------------------------------------+
| Level   | Code | Message                                       |
+---------+------+-----------------------------------------------+
| Warning | 1292 | Truncated incorrect DOUBLE value: '1agavagag' |
+---------+------+-----------------------------------------------+
1 row in set (0.00 sec)

Not a bug.