mysql 判斷字符串是否數字

MySQL判斷字符串是不是數字

2012/8/31 10:10:30

查詢表table_name中col_name（字符串類型）的值是數字的記錄 
SELECT col_name,CAST(col_name AS UNSIGNED INTEGER) AS val 
FROM table_name 
WHERE col_name="0" OR col_name>0 
HAVING CHAR_LENGTH(col_name)=CHAR_LENGTH(val);