比較運(yùn)算符

比較對(duì)象 比較運(yùn)算符 子查詢

mysql> SELECT * FROM 運(yùn)算符例子;

+----+------+

| id | 數(shù)值 |

+----+------+

| 1 | 1 |

| 2 | 3 |

| 3 | 5 |

| 4 | 7 |

| 5 | 9 |

| 6 | 11 |

| 7 | 13 |

+----+------+

7 rows in set (0.01 sec)

mysql> SELECT * FROM 運(yùn)算符例子2;

+----+------+

| id | 數(shù)值 |

+----+------+

| 1 | 2 |

| 2 | 4 |

| 3 | 6 |

| 4 | 8 |

| 5 | 10 |

| 6 | 12 |

| 7 | 14 |

+----+------+

7 rows in set (0.00 sec)

#查找 運(yùn)算符例子表中 數(shù)值小于 運(yùn)算符例子2表中 id=5(10)的數(shù)據(jù)

mysql> SELECT id,數(shù)值 FROM 運(yùn)算符例子 WHERE 數(shù)值 < (SELECT 數(shù)值 FROM 運(yùn)算符例子2 WHERE id=5);

+----+------+

| id | 數(shù)值 |

+----+------+

| 1 | 1 |

| 2 | 3 |

| 3 | 5 |

| 4 | 7 |

| 5 | 9 |

+----+------+

5 rows in set (0.00 sec)

#10>9=1(true)

mysql> SELECT (SELECT 數(shù)值 FROM 運(yùn)算符例子2 WHERE id=5) > (SELECT 數(shù)值 FROM 運(yùn)算符例子 WHERE id = 1) AS 比較;

+------+

| 比較 |

+------+

| 1 |

+------+

1 row in set (0.00 sec)

#10<9=0(false)

mysql> SELECT (SELECT 數(shù)值 FROM 運(yùn)算符例子2 WHERE id=5) < (SELECT 數(shù)值 FROM 運(yùn)算符例子 WHERE id = 1) AS 比較;

+------+

| 比較 |

+------+

| 0 |

+------+

1 row in set (0.00 sec)

用ANY、SOME或ALL修飾的比較運(yùn)算符

運(yùn)算符/關(guān)鍵字

ANY

SOME

ALL

>、>=

最小值

最小值

最大值

最大值

最大值

最小值

=

任意值

任意值

<>、!=、

任意值

比較對(duì)象 比較運(yùn)算符 ANY(子查詢)

假設(shè)子查詢返回結(jié)果為值1,值2,值3舉例:

值 > ANY(...)

實(shí)際上等于 值 > 值1 OR 值>值2 OR 值>值3

相當(dāng)于 或

ANY

比較對(duì)象 比較運(yùn)算符 SOME(子查詢)

和ANY一樣也相當(dāng)于 或

SOME

比較對(duì)象 比較運(yùn)算符 ALL(子查詢)

假設(shè)子查詢返回結(jié)果為值1,值2,值3舉例:

值 > SOME(...)

實(shí)際上等于 值 > 值1 AND 值>值2 AND 值>值3

相當(dāng)于 與

ALL

[NOT] IN

這個(gè)就相當(dāng)于Python中的find,用來確認(rèn)是兩組數(shù)據(jù)是否相同或不同

值 運(yùn)算符 [NOT] IN (子查詢)

=ANY運(yùn)算符與IN等效

!= ALL或者<>ALL運(yùn)算與NOT IN等效

mysql> select * from 運(yùn)算符例子;

+----+------+

| id | 數(shù)值 |

+----+------+

| 1 | 1 |

| 2 | 3 |

| 3 | 5 |

| 4 | 7 |

| 5 | 9 |

| 6 | 11 |

| 7 | 13 |

+----+------+

7 rows in set (0.00 sec)

mysql> select * from 運(yùn)算符例子2;

+----+------+

| id | 數(shù)值 |

+----+------+

| 1 | 2 |

| 2 | 4 |

| 3 | 6 |

| 4 | 8 |

| 5 | 10 |

| 6 | 12 |

| 7 | 14 |

| 8 | 13 |

+----+------+

8 rows in set (0.00 sec)

mysql> select id,數(shù)值 from 運(yùn)算符例子 WHERE 數(shù)值 != ALL(select 數(shù)值 from 運(yùn)算符例子2 WHERE 數(shù)值);

+----+------+

| id | 數(shù)值 |

+----+------+

| 1 | 1 |

| 2 | 3 |

| 3 | 5 |

| 4 | 7 |

| 5 | 9 |

| 6 | 11 |

+----+------+

6 rows in set (0.00 sec)

mysql> select id,數(shù)值 from 運(yùn)算符例子 WHERE 數(shù)值 NOT IN(select 數(shù)值 from 運(yùn)算符例子2 WHERE 數(shù)值);

+----+------+

| id | 數(shù)值 |

+----+------+

| 1 | 1 |

| 2 | 3 |

| 3 | 5 |

| 4 | 7 |

| 5 | 9 |

| 6 | 11 |

+----+------+

6 rows in set (0.00 sec)

mysql> select id,數(shù)值 from 運(yùn)算符例子 WHERE 數(shù)值 = ANY(select 數(shù)值 from 運(yùn)算符例子2 WHERE 數(shù)值);

+----+------+

| id | 數(shù)值 |

+----+------+

| 7 | 13 |

+----+------+

1 row in set (0.00 sec)

mysql> select id,數(shù)值 from 運(yùn)算符例子 WHERE 數(shù)值 IN (select 數(shù)值 from 運(yùn)算符例子2 WHERE 數(shù)值);

+----+------+

| id | 數(shù)值 |

+----+------+

| 7 | 13 |

+----+------+

1 row in set (0.00 sec)

總結(jié)

以上是生活随笔為你收集整理的larval+mysql+不等于_MySQL学习日记(19)比较运算符的全部?jī)?nèi)容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網(wǎng)站內(nèi)容還不錯(cuò)，歡迎將生活随笔推薦給好友。