Question

我有两个表需要输出到不可编辑的表单中。我需要查询的语法。

TableOne has fields id, customer_id, date, type_id.  
TableTwo has fields type_id, type_name.

我有：

SELECT * FROM TableOne WHERE customer_id=someVariable

但它只是为type_id输出一个数字。我需要它打印出与type_id相关联的type_name，而不是打印出数字。如何更改SQL的语法以使其执行此操作？

Answer 1

只使用LEFT JOIN或INNER JOIN

即使你在t2中没有相应的type_id，LEFT JOIN也会给你所有t1 INNER JOIN仅检索t1和t2中存在相应type_id的结果。

select t1.Id, t1.customer_id, t1.date, t2.type_name
FROM TableOne t1
LEFT JOIN TableTwo t2 on t1.type_id = t2.type_id;

Answer 2

SELECT 
    cus.CustomerID,
    cus.Name,
    cus.Email,
    cus.MobileNo,
    cus.OtherNo,
    bloc.Block,
    flor.FlooerNo,
    flat.FlateNo 
FROM 
    ((Customer cus inner join BuildingBlocks bloc on cus.Block=bloc.BlockId) inner join BuildingFloors flor on cus.Flooler=flor.FlooerID)inner join BuildingFlateNo flat on cus.FlateNo=flat.FlateId 
WHERE
    cus.Isdeleted=false

ms访问查询连接两个表

2 个答案: