当MySQL查询与查询条件不匹配时，它返回第0行

Question

I have a table with a primary key:

Type:INT Length:11 Default:NULL Extra:auto_increment

The table contains 3 records - 0, 1 and 4

When I try...

SELECT the_key FROM the_table WHERE the_key='someRandomString'

...it returns 1 record (primary key 0)

I can solve it with a PHP is_numeric() but why doesn't it return 0 records?

Answer 1

It looks like you're comparing an int column against a string value? It looks like MySQL is converting the string to an int, coming up with 0, and matching that row.

Two options:

1. Don't do that. Don't write comparisons of incompatible types.
2. See if MySQL has an option to go into a stricter mode where it doesn't convert incompatible types automatically.