摘要:
多表查询/*基本连接*/select a.Name,b.Namefrom T_Employee a,T_Department bwhere a.DepartmentId=b.Id/*内连接,消除没有匹配连接条件的项*/select a.Name,b.Namefrom T_Employee a inn... 阅读全文
摘要:
单表操作select Name,Major,InDate from T_Employeeselect 12*12select 12*12 as 计算结果select Name as 姓名,Major,InDate from T_Employeeselect * from T_Employeesele... 阅读全文