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mysql的in函数的反面是什么?_Mysql_Sql - Fatal编程技术网

mysql的in函数的反面是什么?

mysql的in函数的反面是什么?,mysql,sql,Mysql,Sql,使用in函数,我可以找到具有指定值的行: SELECT * FROM table1 WHERE value IN (1,3,4); 但我如何选择不是1,3,4的值: SELECT * FROM table1 WHERE value != (1,3,4); 我想你要找的是而不是: SELECT * FROM table1 WHERE value NOT IN (1,3,4); 我想你要找的是而不是: SELECT * FROM table1 WHERE value NOT IN (1,3,4

使用in函数,我可以找到具有指定值的行:

SELECT * FROM table1 WHERE value IN (1,3,4);
但我如何选择不是1,3,4的值:

SELECT * FROM table1 WHERE value != (1,3,4);

我想你要找的是
而不是

SELECT * FROM table1 WHERE value NOT IN (1,3,4);

我想你要找的是
而不是

SELECT * FROM table1 WHERE value NOT IN (1,3,4);
说明:

  • 在中删除重复项和空值:
    (a,b,b,NULL)
    -->
    (a,b)
  • 将NULL与值进行比较会产生
    false
  • 将NULL与NULL进行比较也会产生
    false
因此:

SELECT COUNT(*) FROM mytable WHERE color IN ('red', 'blue');

不必计算到:

SELECT COUNT(*) FROM mytable;
说明:

  • 在中删除重复项和空值:
    (a,b,b,NULL)
    -->
    (a,b)
  • 将NULL与值进行比较会产生
    false
  • 将NULL与NULL进行比较也会产生
    false
因此:

SELECT COUNT(*) FROM mytable WHERE color IN ('red', 'blue');

不必计算到:

SELECT COUNT(*) FROM mytable;

out-no,不可能的重复out-no,不可能的重复out-no,不可能的重复