MYSQL - 更新COLUMN中字符串的第一个字符串

Question

我想更新MYSQL中列的第一个字符

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

将第一个字符更改为“0”。

我创建了这个例子，并认为我在正确的轨道上......

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

Answer 1

MySQL SUBSTRING不是从0开始。

您可以使用：

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

尝试以下方法：

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

Answer 3

试试这个

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

一种方法是使用CONCAT

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