java - 使用条件和 sqlProjection 连接表

Question

我有以下函数来构建 Hibernate Criteria 以生成分箱数据:

private Criteria getCustomBinResultCriteriaSQL(double binSizeX, double binSizeY, String xVar, String yVar, String customBinQuery) {
    return createCriteria(Residue.class)
            .setProjection(Projections.projectionList()
                    .add(Projections.sqlGroupProjection(
                            "floor(" + xVar + " / " + binSizeX + ") * " + binSizeX + " as xBin, " +
                                    "floor(" + yVar + " / " + binSizeY + ") * " + binSizeY + " as yBin, " +
                                    "CAST (" + customBinQuery + " AS DOUBLE PRECISION) as customBinResult",
                            "xBin, yBin",
                            new String[] { "xBin", "yBin", "customBinResult" },
                            new Type[] { Hibernate.DOUBLE, Hibernate.DOUBLE, Hibernate.DOUBLE })))
            .setResultTransformer(Transformers.aliasToBean(CustomBinResult.class));
}

对于同一个表(残差)中的数据来说，这一切都非常有效，但假设我的数据结构是这样的:

pdbentry:idpdbvarexpmethod:idexpvarresidue:idresvar

pdbentry has a one-to-one relation with expmethod, and a one-to-many relation with residue.

How would I go about joining the residue table with expmethod, based on the criteria-builder above. So in other words: what do I need to add to the criteria to be able to have "expvar" as xVar?

I tried adding something like:

.setFetchMode("pdbentry", FetchMode.JOIN);
.setFetchMode("expmethod", FetchMode.JOIN);

最后，但我仍然无法将“expvar”或“expmethod.expvar”作为xVar。

有什么想法吗？

Answer 1

我通过别名连接表

.createCriteria("rootEntity.foreignEntity", "someAlias")

这使得 rootEntity.foreignEntity.someProperty 可作为 someAlias.someProperty 供 Criteria 查询使用(通常我选择“someAlias”与“foreignEntity”相同)。

由于我通常需要急切获取，因此我倾向于在 createCriteria 调用中使用 Criteria.INNER_JOIN 或 Criteria.LEFT_JOIN。