Question

使用某些包含性条件获取所有数据时，例如列名等于“ blue”或“ yellow”而“ colorval”等于“ 100”时

> mysql> select * from Colors where colorname is not null;
+-----------+----------+
| colorname | colorval |
+-----------+----------+
| blue      | 100      |
| blue      | 200      |
| blue      | 300      |
| red       | 200      |
| red       | 300      |
| red       | 100      |
| red       | 400      |
| yellow    | 100      |
| yellow    | 200      |
| yellow    | 300      |
+-----------+----------+

我希望结果是

> 
+-----------+----------+
| colorname | colorval |
+-----------+----------+
| blue      | 200      |
| blue      | 300      |
| red       | 200      |
| red       | 300      |
| red       | 100      |
| red       | 400      |
| yellow    | 200      |
| yellow    | 300      |
+-----------+----------+

Answer 1

这是需要的条件：

select * from colors 
where colorname is not null and (colorval <> 100 or colorname not in ('blue', 'yellow'))

您需要的是colorval不等于100，并且colorname不应该是同一行中的“ blue”，“ yellow”中的任何一个。
请参见demo。
结果：

| colorname | colorval |
| --------- | -------- |
| blue      | 200      |
| blue      | 300      |
| red       | 200      |
| red       | 300      |
| red       | 100      |
| red       | 400      |
| yellow    | 200      |
| yellow    | 300      |

如果只有这三种颜色，则可以这样简化：

select * from colors 
where colorname is not null and (colorval <> 100 or colorname = 'red')

Answer 2

因此您的查询应该是

a_threads = []
secondList = []
for k in range(20):

    firstList = []

    for n in range(0, 200): 
        thread = threading.Thread(target=functionA,args=(n, ))
        thread.start()
        a_threads.append(thread)

    for thread in a_threads:
        thread.join()

    a_threads = []    

    thread = threading.Thread(target=functionB,args=(m, ))
    thread.start()
    a_threads.append(thread)

Answer 3

select * from Colors where colorname is not null and (colorname ='blue' or colorname='yellow') and colorval <> 100;

MySQL获取所有包含匹配其他条件的数据

3 个答案: