Question

我不确定为什么以下查询会给出＆＃34;单行子查询返回多行＆＃34;如果我遗失任何东西，请告诉我。

CASE
  WHEN s.servprov_gid = 'IFFCO.CAR-60041'
  THEN
    (SELECT E.EQUIPMENT_NUMBER
    FROM S_EQUIPMENT SE,
      EQUIPMENT E,
      SHIPMENT_S_EQUIPMENT_JOIN SSEJ,
      SHIPMENT S
    WHERE SSEJ.SHIPMENT_GID = 'IFFCO/LOGISTICS.L171203007'
    AND SE.S_EQUIPMENT_GID  = SSEJ.S_EQUIPMENT_GID
    AND E.EQUIPMENT_GID     = SE.EQUIPMENT_GID
    AND SSEJ.SHIPMENT_GID   = S.SHIPMENT_GID
    )
  ELSE
    (SELECT MIN(se.equipment_number)
    FROM shipment_s_equipment_join ssej,
      s_equipment se
    WHERE ssej.shipment_gid  = 'IFFCO/LOGISTICS.L171203007'
    AND ssej.s_equipment_gid = se.s_equipment_gid
    AND se.equipment_number IS NOT NULL
    )
END

Answer 1

错误消息非常清楚地告知，在关键字＆＃34;然后＆＃34;之后从子查询返回多行。您可以添加＆＃34; Top 1＆＃34;在SQL Serve4的第一个SELECT关键字之后。或者以＆＃34;和rownum = 1＆＃34;结束子查询结束对于Oracle。以下内容适用于SQL Server。

CASE
  WHEN s.servprov_gid = 'IFFCO.CAR-60041'
  THEN
    (SELECT TOP 1 E.EQUIPMENT_NUMBER
    FROM S_EQUIPMENT SE,
      EQUIPMENT E,
      SHIPMENT_S_EQUIPMENT_JOIN SSEJ,
      SHIPMENT S
    WHERE SSEJ.SHIPMENT_GID = 'IFFCO/LOGISTICS.L171203007'
    AND SE.S_EQUIPMENT_GID  = SSEJ.S_EQUIPMENT_GID
    AND E.EQUIPMENT_GID     = SE.EQUIPMENT_GID
    AND SSEJ.SHIPMENT_GID   = S.SHIPMENT_GID
    )
  ELSE
    (SELECT MIN(se.equipment_number)
    FROM shipment_s_equipment_join ssej,
      s_equipment se
    WHERE ssej.shipment_gid  = 'IFFCO/LOGISTICS.L171203007'
    AND ssej.s_equipment_gid = se.s_equipment_gid
    AND se.equipment_number IS NOT NULL
    )
END

查询正在返回＆＃34;单行子查询返回多行＆＃34;

1 个答案: