MySQL 在mysql中用null替换0
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replace 0 with null in mysql
提问by ben
I want to replace 0's in mysql table with 'NULL'. I have read that querying the following way would replace 'NULL' with 0
我想用'NULL'替换mysql表中的0。我已经读过查询以下方式会将“NULL”替换为 0
SELECT COALESCE(null_column, 0) AS null_column FROM whatever;
But how to the other way?
但是反过来呢？
回答by LittleBobbyTables - Au Revtheitroad
You can use NULLIF, which will return NULLif the value in the first parameter matches the value in the second parameter.
您可以使用NULLIF,NULL如果第一个参数中的值与第二个参数中的值匹配，它将返回。
SELECT NULLIF(null_column, 0) AS null_column FROM whatever
回答by Hawili
update `whatever` set `null_column` = null where null_column = 0;
回答by Giulio Muscarello
Just use an UPDATEquery, it's way faster: UPDATE table SET value=NULL WHERE value=0.
只需使用UPDATE查询，它的方式更快：UPDATE table SET value=NULL WHERE value=0。
回答by Siddharth
I used
我用了
UPDATE userDetails set fame=0 where fame IS NULL;
UPDATE userDetails 设置成名= 0，其中成名为空；
if it to work. Since =did not work for me.
如果它工作。因为=对我不起作用。
