table #1:
| Field | Type | Null | Key | Default | Extra |
|---|---|---|---|---|---|
| UserID | int(11) | NO | PRI | NULL | auto_increment |
| Password | varchar(20) | NO | |||
| Username | varchar(25) | NO | |||
| varchar(60) | NO |
table #2:
| Field | Type | Null | Key | Default | Extra |
|---|---|---|---|---|---|
| UserID | int(11) | NO | MUL | ||
| PostID | int(11) | NO | PRI | NULL | auto_increment |
| Title | varchar(50) | NO | |||
| Summary | varchar(500) | NO |
Error:
com.mysql.jdbc.exceptions.MySQLIntegrityConstraintViolationException:
Cannot add or update a child row: a foreign key constraint fails
(myapp/table2, CONSTRAINTtable2_ibfk_1FOREIGN KEY (UserID)
REFERENCEStable1(UserID))
What have I done wrong? I read http://www.w3schools.com/Sql/sql_foreignkey.asp and I don’t see what’s wrong.