MySQL: “Column 'column_name' in where clause is ambiguous”

Question

I JOIN 2 tables

for example

table_A
+---------+-----------+-----------+
| user_id | ticket_id | user_name |
+---------+-----------+-----------+

table_B
         


        

Answer 1

What SQL mode are your two servers in? I could imagine that one is set to be more strict than the other.