请求在SQL / Oracle上工作，但在Java Hibernate HQL上工作

Question

I have the following request which work fine in oracle :

SELECT SUM(col1_sum + col2_sum + col3_sum) AS sum_total FROM ( 
   SELECT 
      COUNT(CASE WHEN (col1 != 0) THEN 1 END) AS col1_sum, 
      COUNT(CASE WHEN (col2 IS NULL) THEN 1 END) AS col2_sum, 
      COUNT(CASE WHEN (col3 IS NULL OR col 3 < 0) THEN 1 END) AS col3_sum 
    FROM myTable)
;

It return the right sum according to all my condition

But when I translate it into HQL like this :

@Query("SELECT SUM(col1_sum + col2_sum + col3_sum) AS sum_total FROM ( "
   +"SELECT "
   +" COUNT(CASE WHEN (col1 != 0) THEN 1 END) AS col1_sum, "
   +" COUNT(CASE WHEN (col2 IS NULL) THEN 1 END) AS col2_sum, "
   +" COUNT(CASE WHEN (col3 IS NULL OR col 3 < 0) THEN 1 END) AS col3_sum "
   +"FROM myTable)")

I could compile my project without error, but when I launch it, I have the following error from hibernate :

2018-03-08 11:18:54.485 [NO_USER NO_SESSION] ERROR ohhiaErrorCounter : line 1:96: unexpected token: ( antlr.NoViableAltException: unexpected token: ( at org.hibernate.hql.internal.antlr.HqlBaseParser.fromRange(HqlBaseParser.java:1544) [....] Caused by: java.lang.IllegalArgumentException: org.hibernate.hql.internal.ast.QuerySyntaxException: unexpected token: ( near line 1, column 96 [...]

Apparently hibernate do not reconize my query after the FROM ( on the first line

Is there any way to correctly convert my Oracle/SQL request into Hibernate/HQL ?

Answer 1

使用SQL而不是HQL的本机查询的Hibernate批注是@NamedNativeQuery，而不是@Query。

Answer 2

That is because Hibernate doesn't support subquery in the FROM clause. Refer to the discussion Cannot use subqueries in from clause. Is there an alternativ .

You may need to use @NamedNativeQuery that allows you to pass Native SQL, that way you can use subquery in FROM clause or see you rewrite your query without subquery in the FROM clause.

Answer 3

Thanks for your answer, I have found a way to do it without using @NamedNativeQuery. I had refactor my SQL query and apparently now Hibernate understand it correctly.

Now, on my java code, the query look like :

@Query("SELECT ((COUNT(CASE WHEN (col1 != 0) THEN 1 END)) + "
        + "(COUNT(CASE WHEN (col2 IS NULL) THEN 1 END)) + "
        + "(COUNT(CASE WHEN (col3 IS NULL OR col3 < 0) THEN 1 END))) AS total "
        + "FROM myTable")

It's work fine with that. I think the issue was not the subquery in my requset (I have other request with subquery which work fine) but the "SUM" keyword.