MySQL默认值选型是空,还是 NULL-爱可生
2020年6月17日 - 网易
1)字段是字符时,你无法一目了然的区分这个值到底是NULL,还是字符串'NULL'insertintot1(name,number)values('NULL',5);insertintot1(number)values(6);select*fromt1wherenumberin(5,6);+---+---+---+|id|name|number|+---+---+---+|5|...
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1)字段是字符时,你无法一目了然的区分这个值到底是NULL,还是字符串'NULL'insertintot1(name,number)values('NULL',5);insertintot1(number)values(6);select*fromt1wherenumberin(5,6);+---+---+---+|id|name|number|+---+---+---+|5|...