Perhaps someone can help me with an example I've come up with to help me to better understand how to build a relationship in Mysql. I have database name “members†and two table name “registered†and “Screen†Registered table: First name Last name User name Password Screen table: Title Category Date Comments What they do is that when member log in from registered table, then input information then send data to the Screen table. Now I have two questions: 1) How would or SHOULD I go about creating the database relationship to show that the screen table is come from right user name! 2) How do I create insert statement into the Screen table that come from right user name! Please help thanks. AM
Regarding #1, it depends on the relationship of the two entities. Will there be only 1 screen entry for each user? If so, a 1-to-1 relationship is appropriate. Will there be more than 1 screen entry per user, then you have a 1-to-many relationship, etc. Model to meet your requirements. Regarding #2, you should have the users rec id in the session or persisted in some temporary store after login. Use the value as needed to insert the record into the database. I just noticed that the Registered table does not have a numeric record identifier. I would suggest you add this unless you want to join on the VARCHAR username column (I recommend not doing so). Anyway, back to an example: Registered UserRecID FirstName LastName UserName Password Screen ScreenRecID UserRecID Title Category Date Comments After a user logs in, you should have the UserRecID value. When the user saves a Screen record your insert will look something like this ... INSERT into dbo.Screen (UserRecID, Title, Category, Date, Comments) VALUES (1234, "Some Title", "Some Category", 10-10-2008, "Some Comments"). The 1234 value is the UserRecID from the logged in user. I hope this makes sense and gets you moving in the right direction. I assumed a 1-to-many relationship, but the approach is the same. Just model and update the SQL as needed. Good luck.