MYSQL - 列

Question

串的UPDATE第一個字符我想更新的列的第一個字符在MYSQL

WHERE the format of the string is LIKE '1-%' 

變化的第一個字符爲「0」。

我創造了這個例子，認爲我是在正確的軌道......

UPDATE products 
SET 
    has_roundel = REPLACE(has_roundel, SUBSTRING(has_roundel, 0, 1),'0') 
WHERE 
    has_roundel like '1-%'; 

Answer 1

的MySQL SUBSTRING心不是從0

開始可以使用：

UPDATE products 
SET 
    has_roundel = REPLACE(has_roundel, SUBSTRING(has_roundel, 1, 1),'0') 
WHERE 
    has_roundel like '1-%'; 

或者：

UPDATE products 
SET 
    has_roundel = REPLACE(has_roundel, SUBSTRING(has_roundel, 1),'0') 
WHERE 
    has_roundel like '1-%'; 

Answer 2

嘗試以下操作：

update products 
set 
    has_roundel = concat('0', substring(has_roundel, 2)) 
where 
    has_roundel like '1-%'; 

Answer 3

試試這個

UPDATE products 
SET 
    has_roundel = REPLACE(has_roundel, LEFT(has_roundel,1),'0') 
WHERE 
    has_roundel like '1-%'; 

或者：

UPDATE products 
    SET 
     has_roundel = Concat('0',SUBSTR(data, 2)) 
    WHERE 
     has_roundel like '1-%'; 

Answer 4

的一種方法是利用CONCAT

UPDATE products 
SET 
    has_roundel = CONCAT('0-', substring(has_roundel, 3)) 
WHERE 
    has_roundel like '1-%';