The string converted to an integer. If the string is a number then the absolute value of the literal will be returned as an integer. Otherwise 0 is returned.
atoi returns its argument as an integer. If the string cannot be parsed and converted to a valid integer, a value 0 is returned.
SQL> select atoi('1.23456789');
callret
INTEGER
_______________________________________________________________________________
1
1 Rows. -- 5 msec.
SQL> select atoi ('Cadena de los patos amarillos');
callret
INTEGER
_______________________________________________________________________________
0
1 Rows. -- 4 msec.