hi there I want update a field plus one.
嗨,我想要更新一个字段加一个。
for example:
if 0 -> 0+1
if 1 -> 1+1
if do it with this code:
如果使用此代码:
UPDATE article SET likehits = '+1' WHERE id ='129'
for all result, the result is 1.
对于所有结果,结果是1。
what's the wrong?
怎么了?
1 个解决方案
#1
1
likehits = '+1' will not actually adds one to a field instead it will just assign literal +1 to likehits column value.
likehits ='+ 1'实际上不会向字段添加一个,而只是将字面值+1分配给likehits列值。
In order to add 1 try this
为了添加1尝试这个
UPDATE article
SET likehits = likehits + 1
WHERE id ='129'
However, it looks like likehits column is of type nvarchar, if so then try this (assuming likehits column stores only numbers)
但是,看起来likehits列的类型为nvarchar,如果是,那么试试这个(假设likehits列只存储数字)
UPDATE article
SET likehits = CAST((CAST(likehits AS INT) + 1) AS nvarchar(64))
WHERE id ='129'
#1
1
likehits = '+1' will not actually adds one to a field instead it will just assign literal +1 to likehits column value.
likehits ='+ 1'实际上不会向字段添加一个,而只是将字面值+1分配给likehits列值。
In order to add 1 try this
为了添加1尝试这个
UPDATE article
SET likehits = likehits + 1
WHERE id ='129'
However, it looks like likehits column is of type nvarchar, if so then try this (assuming likehits column stores only numbers)
但是,看起来likehits列的类型为nvarchar,如果是,那么试试这个(假设likehits列只存储数字)
UPDATE article
SET likehits = CAST((CAST(likehits AS INT) + 1) AS nvarchar(64))
WHERE id ='129'