Question

我有三张表如下所示。

usedetails [ID，first_name，last_name，telephone，email]
地址[ID，streetnumber，streetname，town，county，postcode，userdetailsID]
预订[ID，customerID，pickup_address_id，dropoff_address_id，charge，no_of_passenger]

地址表包含两种类型的地址，即拾取和丢弃。我想将两个地址中的每一个显示为一个字符串。以下是我的查询。

query = "SELECT A.streetnumber,
                        A.streetname,
                        A.town,
                        A.postcode
                    AS pickup_point
                        AB.streetnumber,
                        AB.streetname,
                        AB.town,
                        AB.postcode
                    AS  dropoff_point
                        UD.first_name,
                        UD.last_name,
                        UD.telephone,
                        UD.email
                    FROM userdetails UD 
                    INNER JOIN booking B
                    ON B.customerID = UD.ID
                    INNER JOIN address A
                    ON B.pickup_address_id = A.ID
                    INNER JOIN address AB
                    ON AB.drop_off_address_id = A.ID
                    WHERE UD.ID = A.userdetailsID OR UD.ID = AB.userdetailsID";

Answer 1

尝试CONCAT功能：

SELECT CONCAT(A.streetnumber,
              ' ',
              A.streetname,
              ' ',
              A.town,
              ' ',
              A.postcode) AS pickup_point, ...

或CONCAT_WS函数将分隔符作为第一个参数传递：

SELECT CONCAT_WS(' ',
                 A.streetnumber,
                 A.streetname,
                 A.town,
                 A.postcode) AS pickup_point, ...

SQL在查询多个表时组合同一个表中的多个列

1 个答案: