NOT, !

Logical NOT. 逻辑非。Evaluates to 1 if the operand is 0, to 0 if the operand is nonzero, and NOT NULL returns NULL.如果操作数为0，则计算结果为1；如果操作数为非零，则计算结果为0，而NOT NULL则返回NULL。

mysql> SELECT NOT 10;
        -> 0
mysql> SELECT NOT 0;
        -> 1
mysql> SELECT NOT NULL;
        -> NULL
mysql> SELECT ! (1+1);
        -> 0
mysql> SELECT ! 1+1;
        -> 1

The last example produces 1 because the expression evaluates the same way as (!1)+1.上一个示例生成1，因为表达式的计算方式与(!1)+1相同。

The !, operator is a nonstandard MySQL extension. 这个!运算符是一个非标准的MySQL扩展。As of MySQL 8.0.17, this operator is deprecated; expect it to be removed in a future version of MySQL. 从MySQL8.0.17开始，这个运算符就被弃用了；希望在MySQL的未来版本中删除它。Applications should be adjusted to use the standard SQL NOT operator.应用程序应该调整为使用标准SQL的NOT运算符。

AND, &&

Logical AND. 逻辑与。Evaluates to 1 if all operands are nonzero and not NULL, to 0 if one or more operands are 0, otherwise NULL is returned.如果所有操作数均为非零且不为NULL，则计算结果为1；如果一个或多个操作数为0，则计算结果为0，否则返回NULL。

mysql> SELECT 1 AND 1;
        -> 1
mysql> SELECT 1 AND 0;
        -> 0
mysql> SELECT 1 AND NULL;
        -> NULL
mysql> SELECT 0 AND NULL;
        -> 0
mysql> SELECT NULL AND 0;
        -> 0

The &&, operator is a nonstandard MySQL extension. &&运算符是一个非标准的MySQL扩展。As of MySQL 8.0.17, this operator is deprecated; expect support for it to be removed in a future version of MySQL. 从MySQL8.0.17开始，这个操作符就被弃用了；在MySQL的未来版本中，对它的支持可能会被删除。Applications should be adjusted to use the standard SQL AND operator.应用程序应该调整为使用标准SQL的AND运算符。

OR, ||

Logical OR. 逻辑或。When both operands are non-NULL, the result is 1 if any operand is nonzero, and 0 otherwise. 当两个操作数都非NULL时，如果任何操作数都非零，则结果为1，否则为0。With a NULL operand, the result is 1 if the other operand is nonzero, and NULL otherwise. 对于NULL操作数，如果另一个操作数不为零，则结果为1，否则为NULL。If both operands are NULL, the result is NULL.如果两个操作数都为NULL，则结果为NULL。

mysql> SELECT 1 OR 1;
        -> 1
mysql> SELECT 1 OR 0;
        -> 1
mysql> SELECT 0 OR 0;
        -> 0
mysql> SELECT 0 OR NULL;
        -> NULL
mysql> SELECT 1 OR NULL;
        -> 1

The ||, operator is a nonstandard MySQL extension. ||运算符是一个非标准的MySQL扩展。As of MySQL 8.0.17, this operator is deprecated; expect support for it to be removed in a future version of MySQL. 从MySQL8.0.17开始，这个运算符就被弃用了；在MySQL的未来版本中，对它的支持可能会被删除。Applications should be adjusted to use the standard SQL OR operator. 应用程序应该调整为使用标准SQL的OR运算符。Exception: Deprecation does not apply if PIPES_AS_CONCAT is enabled because, in that case, || signifies string concatentation.例外情况：如果启用了PIPES_AS_CONCAT，则不适用弃用，因为在这种情况下，||表示字符串串联。

XOR

Logical XOR. 逻辑异或。Returns NULL if either operand is NULL. 如果任一操作数为NULL，则返回NULL。For non-NULL operands, evaluates to 1 if an odd number of operands is nonzero, otherwise 0 is returned.对于非NULL操作数，如果奇数个操作数为非零，则计算结果为1，否则返回0。

mysql> SELECT 1 XOR 1;
        -> 0
mysql> SELECT 1 XOR 0;
        -> 1
mysql> SELECT 1 XOR NULL;
        -> NULL
mysql> SELECT 1 XOR 1 XOR 1;
        -> 1

a XOR b is mathematically equal to (a AND (NOT b)) OR ((NOT a) and b).a XOR b在数学上等于(a AND (NOT b)) OR ((NOT a) and b)。