String To Integer

-- SQL cast string to integer

SELECT intValue = CAST ('123456' as INT)

-- Result: 123456

-- SQL convert string to integer 

SELECT intValue = CONVERT (INT, '00123456')

-- Result: 123456              

SELECT intValue = CAST ('123,456' as INT)

/* Error 

Msg 245, Level 16, State 1, Line 5

Conversion failed when converting the varchar value '123,456' to data type int.

*/