Finding number position in string

Question

Below is what I have in table myTable

+++++++++++++++
+ id + myWord +
+++++++++++++++
+  1 + AB123  +
+  2 + A413D  +
+  3 + X5231  +
+  4 + ABE         


        

Answer 1

If you do this often with MySQL, you better make a Stored Function using the string functions SUBSTRING() and ASCII().

DELIMITER //;
CREATE FUNCTION find_first_int(pData CHAR(10))
  RETURNS INT
BEGIN
  DECLARE vPos INT DEFAULT 1;
  DECLARE vRes INT DEFAULT 0;
  DECLARE vChar INT;
  WHILE vPos <= LENGTH(pData) DO
    SET vChar = ASCII(SUBSTR(pData, vPos, 1));
    IF vChar BETWEEN 48 AND 57 THEN
      RETURN vPos;
    END IF;
    SET vPos = vPos + 1;
  END WHILE;
  RETURN NULL;
END//
DELIMITER ;//

The result:

mysql> SELECT id, myWord, find_first_int(myWord) AS myPos FROM t1;
+------+--------+-------+
| id   | myWord | myPos |
+------+--------+-------+
|    1 | AB123  |     3 |
|    2 | A413D  |     2 |
|    3 | X5231  |     2 |
|    4 | ABE921 |     4 |
|    5 | ABC    |  NULL |
+------+--------+-------+

The NULL result can be changed using the function IFNULL().

Note that the function only accepts CHAR(10), so you might want to change that for longer data.