根据条件确定要连接的表 [英] Determine table to join based on the condition

问题描述

我不确定我是否错过了正确的搜索，但我无法得到确切的问题，因为我的



这是类似但不准确的



确定要加入的表格



实际上我想根据哪个表决定加入哪个表格场地价值基础



种类



从表1中选择*

左连接（table1.field = 1时的情况，然后是Table2，否则Table3结束）最终
Table1.Col1 = final.Col1上的




表2和表3有相同的结构







这是我的桌面细节，

i有3个表employee_master，employee_timing和designation_timing。现在，员工主人中有一个字段，即自定义时间。我想在employee_timing和designation_timing的基础上计算员工的时间，但是如果employee_master的字段customtime为true，那么在加入此表时有一个条件，那么我必须与表employee_timing一起加入其他明智的与assign_timing

I am not sure if I have missed to search properly, but I couldn't get the exact question as mine

This is something similar but not exact

DETERMINING WHICH TABLE TO JOIN TO

Actually I want to decide with which table to join based on the bases of field value

Kind of

select * from Table1
left join (case when table1.field=1 Then Table2 else Table3 end) final
on Table1.Col1 = final.Col1

Table2 and Table3 has same structure



Here is my table detail,
i had 3 tables employee_master ,employee_timing & designation_timing. now, there is one field in employee master i.e customizedtime. I want to calculate the time of employee on the bases of employee_timing & designation_timing but there is one condition while joining this table if employee_master's field customizedtime is true then i have to join with table employee_timing other wise with designation_timing

推荐答案

这里可以找到一个非常好的答案..

http://stackoverflow.com/questions/15989593/determine-table-to-join-based-on-the-condition [ ^ ]

A very good answer can be found here..
http://stackoverflow.com/questions/15989593/determine-table-to-join-based-on-the-condition[^]

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