There are three tables
Table 1:
MedID MedName MedProductArea
1 test CS

Table 2:
MedID Row Column SubNum
1 2 1 2

Table 3:
MedID MedName MedValidDate
1 to test the 2020-04-09


1. Table 1 MedName known as the "test", how to acquire the MedValidDate table 3 fields content?

2. Known Row of table 2 to 2, the Column is 1, SubNum to 2, how to acquire the MedValidDate table 3 fields content?

CodePudding user response:

Associated with the luo

CodePudding user response:

reference 1st floor weixin_41985389 response:

associated the luo

Is the associative table, I just don't know how to write this query