java - 如何在 hibernate 中使用 UNION 执行查询

Question

我正在通过 hibernate 执行 SQL 查询，如下所示:

@Query("(select category from Category category where category.isDelete=false and category.status='A' AND " +
        "category.id in (select cat.id from Category cat where cat.isDelete=false and cat.status='A' and cat.parentCategory IS NOT NULL))" +
        "UNION" +
        "(select category from Category category where category.isDelete=false and category.status='A' and category.parentCategory IS NOT NULL)")

但它显示错误

Caused by: java.lang.IllegalArgumentException: node to traverse cannot be null!

Answer 1

您的查询在 sql 级别没有问题，但在 Hibernate 的情况下您将面临此异常

Caused by: java.lang.IllegalArgumentException: node to traverse cannot be null!

所以转换这个查询

@Query("(select category from Category category where category.isDelete=false and category.status='A' AND " +
    "category.id in (select cat.id from Category cat where cat.isDelete=false and cat.status='A' and cat.parentCategory IS NOT NULL))" +
    "UNION" +
    "(select category from Category category where category.isDelete=false and category.status='A' and category.parentCategory IS NOT NULL)")

分为两个查询

@Query("select category from Category category where category.isDelete=false and category.status='A' AND " +
    "category.id in (select cat.id from Category cat where cat.isDelete=false and cat.status='A' and cat.parentCategory IS NOT NULL)")

@Query("select category from Category category where category.isDelete=false and category.status='A' and category.parentCategory IS NOT NULL")

并通过不同的方法调用它们。