[英]JPA Criteria - Count on WHERE Clause
我正在嘗試在JPA標准查詢中創建以下查詢:
SELECT V.* FROM VENDA V
WHERE
( SELECT COUNT(D.ID) FROM VENDADETALHE D WHERE D.ID IN
( SELECT CVD.DETALHES_ID FROM VENDA_VENDADETALHE CVD WHERE CVD.VENDA_ID = V.ID )
AND ( SELECT I.TIPO FROM ITEM I WHERE I.ID=D.IDITEM ) <> 'SERVICO' ) = 0
AND
( SELECT COUNT(D.ID) FROM VENDADETALHE D WHERE D.ID IN
( SELECT CVD.DETALHES_ID FROM VENDA_VENDADETALHE CVD WHERE CVD.VENDA_ID = V.ID )
AND ( SELECT I.TIPO FROM ITEM I WHERE I.ID=D.IDITEM ) = 'SERVICO' ) > 0
我有以下課程結構
public class Venda {
/* other class attributes ( id & etc... ) */
@OneToMany( orphanRemoval=true, cascade = CascadeType.ALL, fetch =FetchType.LAZY )
@JoinTable
private List<VendaDetalhe> detalhes;
}
public class VendaDetalhe{
/* other class attributes */
@ManyToOne
@JoinColumn( name = "iditem", referencedColumnName = "id")
private Item item;
}
public class Item{
/* other class attributes */
@Enumerated( EnumType.STRING )
private ETipo tipo;
}
public enum ETipo{
PRODUTO,
SERVICO;
}
和以下代碼進行查詢:
CriteriaBuilder builder = em.getCriteriaBuilder();
CriteriaQuery<Venda> qry = builder.createQuery( Venda.class );
Root<Venda> root = qry.from( Venda.class );
Join<Venda,VendaDetalhe> join = root.join( "detalhes", JoinType.INNER );
List<Predicate> p = new ArrayList<>();
p.add( builder.greatherThan( builder.count( builder.equal( join.get( "item" ).get("tipo"), ETipo.SERVICO ) ), 0L ) );
p.add( builder.equal( builder.count( builder.equal( join.get("item" ).get("tipo"),ETipo.PRODUTO) ), 0L) );
qry.where( p.toArray( new Predicate[ p.size() ] );
em.createQuery( qry ).getResultList();
但這會生成一個QuerySyntaxException
,表示需要CLOSE
但=
找到。 我的CriteriaQuery語法正確嗎? 我已經在網上搜索了有關在WHERE子句上使用count
信息,但找不到任何東西。
異常消息如下:
org.hibernate.hql.internal.ast.QuerySyntaxException: expecting CLOSE, found '=' near line 1,
column 249
[select generatedAlias0 from
br.com.koinonia.habil.model.user.movimentacoes.compraevenda.Venda
as generatedAlias0 inner join generatedAlias0.detalhes as generatedAlias1 where
( generatedAlias0.empresa=:param0 ) and ( count(generatedAlias1.item.tipo=:param1)>0L )
and ( count(generatedAlias1.item.tipo=:param2)=0L )]
當您可以運行存在查詢時,請勿運行計數查詢 。 即使您停留在SQL語言(或任何翻譯成SQL的語言,例如JPQL)中,您的優化程序也可能無法接受將COUNT(*) == 0
為NOT EXISTS()
的可能性。並且COUNT(*) > 0
到EXISTS()
。 想象其中一個計數結果為100萬。 您是否真的需要數據庫找出確切的計數值? 還是數據庫一旦知道給定行是否存在就可以停止?
您的原始查詢可以重寫為:
SELECT V.*
FROM VENDA V
WHERE NOT EXISTS (
SELECT 1
FROM VENDADETALHE D
WHERE D.ID IN (
SELECT CVD.DETALHES_ID
FROM VENDA_VENDADETALHE CVD
WHERE CVD.VENDA_ID = V.ID
)
AND (
SELECT I.TIPO FROM ITEM I WHERE I.ID=D.IDITEM
) <> 'SERVICO'
)
AND EXISTS (
SELECT 1
FROM VENDADETALHE D
WHERE D.ID IN (
SELECT CVD.DETALHES_ID
FROM VENDA_VENDADETALHE CVD
WHERE CVD.VENDA_ID = V.ID
)
AND (
SELECT I.TIPO FROM ITEM I WHERE I.ID=D.IDITEM
) = 'SERVICO'
)
當然,與'SERVICO'
進行比較的相關子查詢可以進一步轉換為內部聯接,但是我不確定這是否在這里引起麻煩。
也許,這現在使您更容易用JPQL編寫代碼,但是為什么不通過EntityManager.createNativeQuery(String, Class)
運行SQL查詢。 由於您要投影實體( V.*
),因此可以正常工作。
Hibernate QL中的count
顯然對函數內部的內容非常挑剔,並且不能接受嵌套查詢。 所以這行:
builder.count( builder.equal( join.get( "item" ).get("tipo"), ETipo.SERVICO ) )
需要剝離一下,以便equal
比較位於其他位置,並且僅在單個查詢上調用count
。
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.