php - Mysql中根据列值和分组进行减法

Question

这是我的表结构

我需要根据 GROUP BY Bank 减去存款和取款

预期输出

Bank  balance

1     1000.00

2     300.00

3     500.00

Answer 1

你可以用 case when

    select  bank,  sum( case when  bankType ='Withdrawal' 
                          then -BankRs 
                          else  BankRs  end ) balance
    from your_table  
    group by bank