SQL临时向返回的结果集添加了Count列

下面的代码将两个不同的表连接在一起，并提供所需的离散数据列。问题是我还需要一个列来统计另一个表中的另一个实例。请参见select语句附近的指针引用

  SELECT 
  //count(of records returned from below query and duplicates of those found in outc table),
  outage_duration.dgroup,
  outage_duration.cause,
  outage_duration.cdts,
  outage_duration.cust_minutes,
  outage_duration.evntnum,
  outage_duration.num_cust,
  outage_duration.outage_type,
  outage_duration.substation,
  outage_duration.feeder,
  outage_duration.out_minutes
  FROM outage_duration,
  aeven
  WHERE outage_duration.evntnum    = aeven.num_1
  AND aeven.outage_type            = 'T'
  AND aeven.cdts                  >= '20110101060000UT'
  AND aeven.curent                 = 'T'
  AND aeven.open_and_curent        = 'F'
  AND aeven.ag_id NOT             IN    ('MEMT','MTRRDR','MTRTECH','GRDLT','FSRSR','ELECOPS','AMS','REVSEC')
  AND outage_duration.out_minutes >= '240'
  AND outage_duration.curent = 'T' 
  GROUP BY outage_duration.dgroup, outage_duration.cause, outage_duration.cdts, outage_duration.cust_minutes, outage_duration.evntnum, outage_duration.num_cust, outage_duration.outage_type, outage_duration.substation, outage_duration.feeder, outage_duration.out_minutes
  ORDER BY outage_duration.evntnum

样本AEVEN，大修持续时间表

num_1
T344490
T344410
T344480

outage_duration
T344490
T344410

这将返回T344490和T44410，这就是上面的搜索所做的。现在，有了这些结果，我需要从另一个表中获取一个计数，并将该计数作为它自己的列显示在该表中发生的事件数旁边

outc（第1列=唯一id，第2列=evntnum）

预期结果如下：

 1. T344410, 5, "other columns that were specified"
 2. T344490, 2, "other columns that were specified"

我如何做到这一点

SELECT 
  COUNT(*), --this
  outage_duration.dgroup,
  outage_duration.cause,
  outage_duration.cdts,
  outage_duration.cust_minutes,
  outage_duration.evntnum,
  outage_duration.num_cust,
  outage_duration.outage_type,
  outage_duration.substation,
  outage_duration.feeder,
  outage_duration.out_minutes
  FROM
      outage_duration
      JOIN
      aeven ON outage_duration.evntnum    = aeven.num_1
      JOIN
      outc ON outage_duration.evntnum = outc. --insert column here
  WHERE 
  AND aeven.outage_type            = 'T'
  AND aeven.cdts                  >= '20110101060000UT'
  AND aeven.curent                 = 'T'
  AND aeven.open_and_curent        = 'F'
  AND aeven.ag_id NOT             IN           ('MEMT','MTRRDR','MTRTECH','GRDLT','FSRSR','ELECOPS','AMS','REVSEC')
  AND outage_duration.out_minutes >= '240'
  AND outage_duration.curent = 'T' 
  GROUP BY outage_duration.dgroup, outage_duration.cause, outage_duration.cdts, outage_duration.cust_minutes, outage_duration.evntnum, outage_duration.num_cust, outage_duration.outage_type, outage_duration.substation, outage_duration.feeder, outage_duration.out_minutes
  ORDER BY outage_duration.evntnum

只需将COUNT（*）添加到SELECT位，将表outc添加到FROM

---

您已经有了一个GROUP BY，所以应该在sqldeveloper中设置itn

，它会在我复制粘贴时自动添加。

SELECT 
  COUNT(*), --this
  outage_duration.dgroup,
  outage_duration.cause,
  outage_duration.cdts,
  outage_duration.cust_minutes,
  outage_duration.evntnum,
  outage_duration.num_cust,
  outage_duration.outage_type,
  outage_duration.substation,
  outage_duration.feeder,
  outage_duration.out_minutes
  FROM
      outage_duration
      JOIN
      aeven ON outage_duration.evntnum    = aeven.num_1
      JOIN
      outc ON outage_duration.evntnum = outc. --insert column here
  WHERE 
  AND aeven.outage_type            = 'T'
  AND aeven.cdts                  >= '20110101060000UT'
  AND aeven.curent                 = 'T'
  AND aeven.open_and_curent        = 'F'
  AND aeven.ag_id NOT             IN           ('MEMT','MTRRDR','MTRTECH','GRDLT','FSRSR','ELECOPS','AMS','REVSEC')
  AND outage_duration.out_minutes >= '240'
  AND outage_duration.curent = 'T' 
  GROUP BY outage_duration.dgroup, outage_duration.cause, outage_duration.cdts, outage_duration.cust_minutes, outage_duration.evntnum, outage_duration.num_cust, outage_duration.outage_type, outage_duration.substation, outage_duration.feeder, outage_duration.out_minutes
  ORDER BY outage_duration.evntnum