在同一个表上组合两个SQL SELECT语句 [英] Combining two SQL SELECT statements on the same table

问题描述

我想合并这两个SQL查询：

I would like to combine these two SQL queries:

SELECT * FROM "Contracts" WHERE 
"productType" = 'RINsell' AND
"clearTime" IS NULL AND
"holdTime" IS NOT NULL 
 ORDER BY "generationTime";

和

SELECT * FROM "Contracts" WHERE 
"productType" = 'RINsell' AND
"clearTime" IS NULL AND
"holdTime" IS NULL 
 ORDER BY "contractLimitPrice";

当我运行每个语句时，我得到了我想要的结果， 。我的第一个想法是使用UNION ALL，因为这个选择是不相交的，但我发现你不能在 ORDER BY 后使用 UNION code>。我搜索了很多，大多数人建议在 UNION 之后执行 ORDER BY ，但每个查询有不同的 ORDER BY 条件。

When I run each statement, I get exactly the results I want, I would just like both results sequentially. My first thought was to use UNION ALL since this selections will be disjoint but I found that you can't use a UNION after an ORDER BY. I've searched quite a bit and most people suggest doing the ORDER BY after the UNION but each query has different ORDER BY conditions.

推荐答案

如果您想要第一个查询在第二个结果之前，您可以从where子句中删除 holdtime ，并使用类似

If you want the results of the first query before the results of the second, you can remove holdtime from the where clause, and use an order by like

order by
  case when holdTime is not null then 0 else 1 end, --first query comes first
  case when holdTime is not null --different orders for queries
       then generationTime
       else contractLimitPrice
  end

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