如何使用Spring Data JPA嵌套查詢？

Question

如何將以下SQL轉換為Criteria？

SELECT DISTINCT <column name> FROM <table>
WHERE <some other column> IN 
    (SELECT DISTINCT <column name 2> FROM <table 2> 
    WHERE <some other column 2> IN
        (SELECT <column name 3> FROM <table 3>
        WHERE <some other column 3> IN
            (SELECT <column name 4> from <table 4>
            WHERE <some other column 4> IN (0,1,2,3,4))))

這是我將要搜索的列值類型：

Column           Value Type
<column name>    String
<column name 2>  String
<column name 3>  Long
<column name 4>  Long

Answer 1

SQL翻譯：

SELECT DISTNCT <column name> FROM <table>
WHERE <some other column> IN 
    (SELECT DISTINT <column name 2> FROM <table 2> 
    WHERE <some other column 2> IN
        (SELECT <column name 3> FROM <table 3>
        WHERE <some other column 3> IN
            (SELECT <column name 4> from <table 4>
            WHERE <some other column 4> IN (0,1,2,3,4))))

Column           Value Type
<column name>    String
<column name 2>  String
<column name 3>  Long
<column name 4>  Long

將SQL轉換為JPA標准：

CriteriaBuilder cb = emf.getCriteriaBuilder();
CriteriaQuery<String> cqTable = cb.createQuery(String.class);
Root<table> fromTable = cqTable .from(<table>.class);

Subquery<String> cqTable2 = cqTable.subquery(String.class);
Root<table 2> fromTable2 = cqTable2.from(<table 2>.class);

Subquery<Long> cqTable3 = cqTable2.subquery(Long.class);
Root<table 3> fromTable3 = cqTable3.from(<table 3>.class);

Subquery<Long> cqTable4 = cqTable3.subquery(Long.class);
Root<table 4> fromTable4 = cqTable4.from(<table 4>.class);

    cqTable4 = cqTable4.select(fromTable4.get("column 4").as(Long.class))
.where(fromTable4.get("some other column 4").in(new ArrayList<String>(){{
                                add("0");
                                add("1");
                                add("2");
                                add("3");
                                add("4");}}));

cqTable3 = cqTable3.select(fromTable3.get("column name 3").as(Long.class))
                .where(fromTable3.get("some other column 3")
                        .in(cqTable4));

cqTable2 = cqTable2.select(fromTable2.get("column name 2").as(String.class))
                .distinct(true).where(fromTable2.get("some other column 2")
                        .in(cqTable3));

cqTable = cqTable.select(fromTable.get("column name").as(String.class))
.distinct(true).where(fromTable.get("some other column").in(cqTable2)));

List<String results = emf.createEntityManager().createQuery(cqTable ).getResultList();

我希望這能夠幫助那些努力使用嵌套SELECT和IN子句編寫Criteria的人。