Question

我在下面运行了查询

SELECT 
    SUBSTRING_INDEX(prim_key ,":" , 1) prim_key, 
    SUBSTRING_INDEX(prim_key ,":" , -1) urid, 
    CASE WHEN basicname = 'Q914'  THEN 'SHC'
         WHEN basicname = 'QP913'  THEN 'PHC'
         WHEN basicname = 'QC1214'  THEN 'CHC'
         WHEN basicname = 'QD1014'  THEN 'DH/SDH'
         ELSE 'UNKOWN' 
    END AS Status 
FROM facility_data 
WHERE 1 = 1
    AND basicname in ( 'Q914'  , 'QP913' , 'QC1214' , 'QD1014' ) 
    and prim_key like  '3_10_%' 
ORDER BY  prim_key ASC

我需要略微修改，我希望它显示SHC，DH，PHC和CHC的总数。

所以请告诉我怎么做才能显示shc，dh，phc和chc的总数。

Answer 1

SELECT status
     , Count(*)
FROM   (
        SELECT CASE basicname
                 WHEN 'Q914'   THEN 'SHC'
                 WHEN 'QP913'  THEN 'PHC'
                 WHEN 'QC1214' THEN 'CHC'
                 WHEN 'QD1014' THEN 'DH/SDH'
               END AS status
        FROM   facility_data 
        WHERE  basicname in ('Q914', 'QP913', 'QC1214', 'QD1014' )
        AND    prim_key like  '3_10_%'
       ) As x
GROUP
    BY status

如果您希望按prim_key和urid分组

SELECT prim_key
     , urid
     , status
     , Count(*)
FROM   (
        SELECT SUBSTRING_INDEX(prim_key, ':', +1) As prim_key
             , SUBSTRING_INDEX(prim_key, ':', -1) As urid
             , CASE basicname
                 WHEN 'Q914'   THEN 'SHC'
                 WHEN 'QP913'  THEN 'PHC'
                 WHEN 'QC1214' THEN 'CHC'
                 WHEN 'QD1014' THEN 'DH/SDH'
               END AS status
        FROM   facility_data 
        WHERE  basicname in ('Q914', 'QP913', 'QC1214', 'QD1014' )
        AND    prim_key like  '3_10_%'
       ) As x
GROUP
    BY prim_key
     , urid
     , status

Answer 2

如果仅使用计数获得一行（您使用SUM），则可以在IF内部使用where语句。

 SELECT
     sum(if(basicname = 'Q914',1,0)) as SHC,
     sum(if(basicname = 'QP913',1,0)) as PHC,
     sum(if(basicname = 'QC1214',1,0)) as CHC,
     sum(if(basicname = 'QD1014',1,0)) as DH
 FROM facility_data 
 WHERE
     basicname in ( 'Q914'  , 'QP913' , 'QC1214' , 'QD1014' ) 
     and prim_key like  '3_10_%' 
 ORDER BY  prim_key ASC

如果您想要多行（需要GROUP BY），则使用Using temporary; Using filesort：

 SELECT
     CASE WHEN basicname = 'Q914'  THEN 'SHC'
          WHEN basicname = 'QP913'  THEN 'PHC'
          WHEN basicname = 'QC1214'  THEN 'CHC'
          WHEN basicname = 'QD1014'  THEN 'DH/SDH'
          ELSE 'UNKOWN' 
     END AS Status,
     COUNT(*) as `count`
 FROM facility_data 
 WHERE
     basicname in ( 'Q914'  , 'QP913' , 'QC1214' , 'QD1014' ) 
     and prim_key like  '3_10_%' 
 GROUP BY basicname
 ORDER BY  prim_key ASC

如何从mysql查询中获取多条记录的记录总数

2 个答案: