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

4 votes328 views3 answers
Mysql get column names from table
SQL
0 vote275 views1 answer
How to find columns with null values in sql
SQL
3 votes262 views1 answer
Mysql set field unique
SQL
2 votes263 views1 answer
Oracle log files
SQL
1 vote265 views1 answer
User privileges postgresql information_schema
SQL
2 votes254 views1 answer
Mysql list users on ubuntu
SQL
0 vote288 views1 answer
Multiple replace value mssql
SQL
1 vote295 views3 answers
Psql: error: FATAL: role "postgres" does not exist
SQL
1 vote289 views1 answer
Sqlstate[imssp]: the active result for the query contains no fields.
SQL
0 vote342 views1 answer
Python get backup of sql
SQL