Mysql error 1215

I'm guessing that Clients.Case_Number and/or Staff.Emp_ID are not exactly the same data type as Clients_has_Staff.Clients_Case_Number and Clients_has_Staff.Staff_Emp_ID.

Perhaps the columns in the parent tables are INT UNSIGNED?

They need to be exactly the same data type in both tables.

Mysql error 1215

When you are trying to reference a key on parent table which is not a candidate key (either a primary key or a unique key) you may get the error code: 1215 cannot add foreign key constraint. ... It does not necessarily to be a primary key. MySQL requires index on corresponding referenced key, so you need a unique key

Similar codes

2 votes196 views1 answer
Sql as
SQL
5 votes188 views1 answer
Oracle asynchronous query
SQL
13 votes187 views2 answers
Sql join
SQL
0 vote205 views1 answer
SQL SELECT TOP Equivalent in MySQL
SQL
0 vote206 views1 answer
MySQL get all previous date record
SQL
0 vote241 views3 answers
Mysql CAST(amount as float)
SQL
3 votes194 views3 answers
Django.db.utils.OperationalError: no such table:
SQL
1 vote207 views1 answer
Oracle grant select on schema
SQL
0 vote190 views2 answers
Mysql disable foreign key checks
SQL
0 vote194 views1 answer
Mysql cast null to string
SQL