How do I check to see if a value is an integer in MySQL?

mysql
Craig Nakamoto picture Craig Nakamoto · Sep 16, 2008 · Viewed 152.9k times · Source

I see that within MySQL there are Cast() and Convert() functions to create integers from values, but is there any way to check to see if a value is an integer? Something like is_int() in PHP is what I am looking for.

Answer

Jumpy picture Jumpy · Sep 16, 2008

I'll assume you want to check a string value. One nice way is the REGEXP operator, matching the string to a regular expression. Simply do

select field from table where field REGEXP '^-?[0-9]+$';

this is reasonably fast. If your field is numeric, just test for

ceil(field) = field

instead.

Related questions

How do I import an SQL file using the command line in MySQL?

I have a .sql file with an export from phpMyAdmin. I want to import it into a different server using the command line. I have a Windows Server 2008 R2 installation. I placed the .sql file on the C drive, and …

Read More
How can I prevent SQL injection in PHP?

If user input is inserted without modification into an SQL query, then the application becomes vulnerable to SQL injection, like in the following example: $unsafe_variable = $_POST['user_input']; mysql_query("INSERT INTO `table` (`column`) VALUES ('$unsafe_variable')"); That's …

Read More
MySQL error code: 1175 during UPDATE in MySQL Workbench

I'm trying to update the column visited to give it the value 1. I use MySQL workbench, and I'm writing the statement in the SQL editor from inside the workbench. I'm writing the following command: UPDATE tablename SET columnname=1; It gives …

Read More