SQL_CALC_FOUND_ROWS / FOUND_ROWS() does not work in PHP

Question

I use SQL_CALC_FOUND_ROWS in Mysql SELECT statement, to get the number of lines my SELECT would return without a LIMIT clause.

$sql = new mysqli         


        

Answer 1

Are you using a MySQL query method that allows for multiple queries.

From MySQL documentation.

To obtain this row count, include a SQL_CALC_FOUND_ROWS option in the SELECT statement, and then invoke FOUND_ROWS() afterward

Example:

mysql> SELECT SQL_CALC_FOUND_ROWS * FROM tbl_name
    -> WHERE id > 100 LIMIT 10;
mysql> SELECT FOUND_ROWS();

Also just for fun, there's a great discussion about the race condition of FOUND_ROWS()'s usage here.