I have two table. 1. User_login 2. User_detail user_login table has: 1. user_id 2. username 3. password user_detail table has: 1. key 2. value I have made mistake when I stored data. I stored name with user_id example: firstname_1 --> Dani firstname_2 --> Alex Now I would like to get firstnames how can I concatenate 'firstname' with get value of userid?