First establish the main table sys_student, the owner can choose the following user
Input columns, P primary key, M non-empty
Double-arrow part, each column can be edited
Set the primary key
Click, the primary key is provided in detail, which select a specific column as a primary key
Select specific options are listed in columns
Click OK to complete, vc_stuid column have a <pk> item back, as shown below
Establishing sub-table, the sub-table primary key is also required to establish a method as above, select the column of the primary table as a foreign key
The main parent table is connected
