MySQL的 - 計算與某些條件在主表中的行和等於特定值

Question

我有兩個表，並首次命名表1：

ID | Name | Type | isActive | isDeleted | 
----------------------------------------------- 
1 | item 1 | 4 | 1  | 0  | 
2 | item 2 | 2 | 1  | 0  | 
3 | item 3 | 1 | 1  | 1  | 
4 | item 4 | 1 | 1  | 0  | 
5 | item 5 | 1 | 1  | 0  | 
6 | item 6 | 3 | 1  | 0  | 
7 | item 7 | 1 | 1  | 0  | 
8 | item 8 | 2 | 1  | 0  | 
9 | item 9 | 1 | 1  | 0  | 
10 | item 10 | 1 | 1  | 0  | 

和第二名爲table1_meta：

ID | table1_id | options | value 
------------------------------------ 
1 | 1   | dont_ask | 1 
2 | 2   | dont_ask | 1 
3 | 5   | dont_ask | 1 
4 | 6   | dont_ask | 1 
5 | 8   | alwasys_ask| 1 
6 | 9   | alwasys_ask| 1 
7 | 1   | is_flagged | 1 
8 | 2   | is_flagged | 0 
9 | 3   | is_flagged | 0 
10 | 4   | is_flagged | 0 
11 | 5   | is_flagged | 0 
12 | 6   | is_flagged | 1 
13 | 7   | is_flagged | 0 
14 | 8   | is_flagged | 0 
15 | 9   | is_flagged | 0 
16 | 10   | is_flagged | 0 

我試圖對表1中的行進行計數，其中某些特定條件得到滿足，其中一些條件。

WHERE條件必須包含以下條件：

table1.type = 1 and table1.isActive = 1 and table1.isDeleted = 0 and table1_meta.options = 'is_flagged' and table1_meta.value = 0 

這：

table1_meta.options = 'dont_ask' and table1_meta.value = 1 

這：

table1_meta.options = 'always_ask' and table1_meta.value = 1 

所以，我該怎麼辦呢？

SQLFiddle鏈接：http://sqlfiddle.com/#!2/2eb27b

感謝。

Answer 1

我想我找到了我的問題的答案。

查詢是：

SELECT Count(*) AS total FROM 
     (SELECT Count(*) 
     FROM table1 t1, 
       table1_meta t1meta 
     WHERE t1.type = 1 
       AND t1.isactive = 1 
       AND t1.isdeleted = 0 
       AND t1meta.options = 'is_flagged' 
       AND t1meta.value = 0 
       AND t1.id NOT IN (SELECT table1_id 
           FROM table1_meta tm 
           WHERE tm.options = 'dont_ask' 
             AND tm.value = 1) 
     UNION 
     SELECT Count(*) 
     FROM table1_meta tm, 
       table1 t1 
     WHERE t1.id = tm.table1_id 
       AND tm.options = 'always_ask' 
       AND tm.value = 1) x 

還是要謝謝你，戈登。

Answer 2

我假設您正在嘗試對第一個表中的行進行計數。以下是使用子查詢的一種方法：

select count(*) 
from table1 t1 
where t1.type = 1 and t1.isActive = 1 and t1.IsDeleted = 0 and 
     exists (select 1 
       from table1_meta tm 
       where t1.id = tm.table1_id and tm.options = 'is_flagged' and tm.value = 0 
      ) and 
     not exists (select 1 
        from table1_meta tm 
        where t1.id = tm.table1_id and 
         tm.options = 'dont_ask' and tm.value = 1 
       ) and 
     exists (select 1 
       from table1_meta tm 
       where t1.id = tm.table1_id and 
        tm.options = 'always_ask' and tm.value = 1 
      ); 

這對元表中的每個條件都有單獨的子查詢。