将复杂的嵌套 SQL 子查询转换为 JOOQ

Question

我在将 SQL 查询转换为 JOOQ 时遇到了一些问题。所以 join 子句中的别名 sugActive 是未知的。可能有更好的方法来写这个。所以，我仍然无法弄清楚出了什么问题。我感谢任何提示，在此先感谢。

1. The SQL query:

        select
        count(campId) as 'campCount',
        count(case when targetTest != 0 then campId else null end) as 'targetTestSet',
        count(case when targetTest = 0 then campId else null end) as 'targetTestNotSet',
        coalesce(sum(sugActive), 0) as 'sugActive',
        coalesce(sum(sugApproved), 0) as 'sugApproved',
    from (
        select 
            c.venId,
            c.name,
            s.*
        from campTable c
        join (select s.campId,
                    count(case when s.status = 'ACTIVE'
                        then id end) as 'sugActive',
                    count(case when s.status = 'APPROVED'
                        then id end) as 'sugApproved',
                from sugTable s
                group by s.campId
            ) s on c.campId = s.campId
        where c.state = 'enabled'
    ) a;

返回

2. The JOOQ query:

    Field<Integer> sugActive = igDb
    .select(
        count(when(
            sugTable.status.eq("ACTIVE"), sugTable.campId)
            .as("sugActive")))
    .from(sugTable).asField("sugActive");
Field<Integer> sugApproved = igDb
    .select(
            count(when(
                sugTable.status.eq("APPROVED"), sugTable.campId)
                .as("sugApproved")))
    .from(sugTable).asField("sugApproved");
IgOrgSumRecord result = igDb
    .select(
        count(campTable.venId).as("venIdCount"),
        count(sugTable.campId).as("campCount"),
        count(when(
            campTable.targetTest.notEqual(BigDecimal.ZERO), sugTable.campId
            ).otherwise("")).as("targetTestSet"),
        count(when(
            campTable.targetTest.eq(BigDecimal.ZERO), sugTable.campId
            ).otherwise("")).as("targetTestNotSet"),
        coalesce(sum(sugActive)).as("sugActive"),
        coalesce(sum(sugApproved)).as("sugApproved"))
    .from(select(
        campTable.venId,
        campTable.name,
        sugTable.asterisk()
    )
        .from(campTable.as("c"))
        .join(
            select(
                sugTable.campId,
                count(when(
                    sugTable.status.eq("ACTIVE"), sugTable.campId)
                    .as("sugActive")),
                count(when(
                    sugTable.status.eq("APPROVED"), sugTable.campId)
                    .as("sugApproved"))
            )
                .from(sugTable)
                .groupBy(sugTable.campId)
        )
        .on(campTable.campId.eq(sugTable.campId))
        .where(campTable.state.eq("enabled"))
    )
.fetchOneInto(IgOrgSumRecord.class);

返回

我得到的错误：“字段列表”中的未知列“sugActive”。

Answer 1

问题是这样的：

Field<Integer> sugActive = igDb
    .select(
        count(when(
            sugTable.status.eq("ACTIVE"), sugTable.campId)
            .as("sugActive")))
    .from(sugTable).asField("sugActive");

这不仅仅是一个列表达式，它是一个别名声明（或引用）。然后，当您真正想要使用表达式时，您将使用别名引用，重新为其设置别名：

coalesce(sum(sugActive)).as("sugActive"),

相反，像这样声明您的 sugActive 变量：

Field<Integer> sugActive = field(igDb
    .select(
        count(when(
            sugTable.status.eq("ACTIVE"), sugTable.campId)
            .as("sugActive")))
    .from(sugTable));

另请参阅此处的说明：https://github.com/jOOQ/jOOQ/issues/10119