A string function that returns the integer ASCII code value of the first (leftmost) character of a string expression.

ASCII(string-expression)
{fn ASCII(string-expression)}

ASCII returns NULL if passed a NULL or an empty string value. The returning of NULL for empty string is consistent with SQL Server.

Note that ASCII can be invoked as an ODBC scalar function (with the curly brace syntax) or as an SQL general function.

The following examples both returns 90, which is the ASCII value of the character Z:

SELECT ASCII('Z') AS AsciiCode

SELECT {fn ASCII('ZEBRA')} AS AsciiCode 

InterSystems SQL converts numerics to canonical form before performing ASCII conversion. The following example returns 55, which is the ASCII value of the number 7:

SELECT ASCII(+007) AS AsciiCode

This number parsing is not done if the numeric is presented as a string. The following example returns 43, which is the ASCII value of the plus (+) character:

SELECT ASCII('+007') AS AsciiCode