Question

in SQL, char() converts an integer to a character (e.g., char(101) returns ‘e’). What’s the reverse function of char() (e.g., convert ‘e’ to 101)?

Answer 1

ORD() or ASCII(), though they’re not strictly a reverse since they will only handle the first character of the string passed in whereas CHAR() can build a string from a list of digits.

As per Michael Buen’s answer it’s worth noting that ORD() is MySql-only, whereas ASCII() is more widely supported but doesn’t handle multi-byte characters.

mysql> SELECT CHAR(104), ASCII('h'), ORD('h');
+-----------+------------+----------+
| CHAR(104) | ASCII('h') | ORD('h') |
+-----------+------------+----------+
| h         |        104 |      104 |
+-----------+------------+----------+