MySQL查询IF条件和分组依据

Question

SELECT      ps.job_no, ps.booking_no,
            ps.type,ps.shipped_by, ps.invoice_no,
            ps.transporters_id,ps.clients_id,ps.return_terminal,
            ps.destinations_id,ps.forwarder_name,              
            containers.container_size,containers.container_no,
            containers.truck_no,
            ps.driver_cell_no,ps.shipping_line_name,
            containers.cro_no,vessels.vessel_name,vessels.eta,
            containers.empty_pickup_point,containers.loading_point,
            ps.particular 
  FROM      planning_sheet AS ps 
                LEFT JOIN vessels 
                    ON vessels.bookingno= ps.booking_no
                LEFT JOIN containers 
                    ON containers.bookingno = ps.booking_no
GROUP BY ps.clients_id 

我是构建此类复杂查询的新手，查询定义如下，我希望此查询中针对“ clients_id”的所有记录我针对此查询得到一条记录。

我也想在“类型= 0”中的“类型”列中写入“空气”或“类型= 1”而不是“海洋”。

Answer 1

在使用GROUP BY子句之前，您必须先聚合一些列。 有关某些汇总功能，请参见此处。 但是，如果要修改type的输出，则可以使用inLine Case语句。

SELECT  ....,
        CASE ps.`type`
           when 0 then 'Air'
           when 1 then 'Sea'
        END as `type`,
        ....
FROM    .... 

Answer 2

您可以将其放入查询中

select
CASE type 
      when '0' then 'Air'
      when '1' then 'Sea'
END as type 

Answer 3

尝试这个：：

SELECT      ps.job_no, ps.booking_no,
            ps.type,ps.shipped_by, ps.invoice_no,
            ps.transporters_id,ps.clients_id,ps.return_terminal,
            ps.destinations_id,ps.forwarder_name,              
            containers.container_size,containers.container_no,
            containers.truck_no,
            ps.driver_cell_no,ps.shipping_line_name,
            containers.cro_no,vessels.vessel_name,vessels.eta,
            containers.empty_pickup_point,containers.loading_point,
            ps.particular ,
           CASE ps.type when '0' then 'Air'
when '1' then 'Sea'
END as type
  FROM      planning_sheet AS ps 
                LEFT JOIN vessels 
                    ON vessels.bookingno= ps.booking_no
                LEFT JOIN containers 
                    ON containers.bookingno = ps.booking_no

Answer 4

尝试这个..

SELECT      ps.job_no, ps.booking_no,
            CASE ps.type WHEN 0 THEN 'Air' WHEN 1 THEN 'Sea' ELSE 'None' END 
            as PLAN_TYPE,
            ps.shipped_by, ps.invoice_no,
            ps.transporters_id,ps.clients_id,ps.return_terminal,
            ps.destinations_id,ps.forwarder_name,              
            containers.container_size,containers.container_no,
            containers.truck_no,
            ps.driver_cell_no,ps.shipping_line_name,
            containers.cro_no,vessels.vessel_name,vessels.eta,
            containers.empty_pickup_point,containers.loading_point,
            ps.particular 
  FROM      planning_sheet AS ps 
                LEFT JOIN vessels 
                    ON vessels.bookingno= ps.booking_no
                LEFT JOIN containers 
                    ON containers.bookingno = ps.booking_no

根据ps.type数据类型使用

CASE ps.type WHEN 0 THEN 'Air' WHEN 1 THEN 'Sea' ELSE 'None' END

要么

CASE ps.type WHEN '0' THEN 'Air' WHEN '1' THEN 'Sea' ELSE 'None' END