mysql - 如何在 postgres 的这个查询中使用函数计数

Question

我需要为每个“Tecnico”计算“Estado de solicitud”，我的意思是，对于每个“Tecnico”我有多少“Abiertos”或“En espera”

这是我的

SELECT ti.FIRST_NAME AS "Técnico", std.STATUSNAME AS "Estado de solicitud"  
FROM WorkOrder wo 
LEFT JOIN WorkOrderStates wos ON wo.WORKORDERID=wos.WORKORDERID 
LEFT JOIN SDUser td ON wos.OWNERID=td.USERID 
LEFT JOIN AaaUser ti ON td.USERID=ti.USER_ID 
LEFT JOIN StatusDefinition std ON wos.STATUSID=std.STATUSID 
WHERE ( std.STATUSID != 3  ) AND (std.STATUSID != 4)

Answer 1

您可以使用条件聚合来做到这一点:

SELECT ti.FIRST_NAME AS "Técnico",
       COUNT(*) FILTER (WHERE std.STATUSNAME = 'Abierto') as abiertos,
       COUNT(*) FILTER (WHERE std.STATUSNAME = 'En Espera') as en_esperas
FROM WorkOrder wo LEFT JOIN
     WorkOrderStates wos
     ON wo.WORKORDERID = wos.WORKORDERID LEFT JOIN
     SDUser td
     ON wos.OWNERID = td.USERID LEFT JOIN
     AaaUser ti
     ON td.USERID = ti.USER_ID LEFT JOIN
     StatusDefinition std
     ON wos.STATUSID = std.STATUSID 
WHERE std.STATUSID NOT IN (3, 4)
GROUP BY ti.FIRST_NAME