我正在使用QueryDsl SQL
,我想要left join
一个子查询。这是普通SQL
中的查询
SELECT
usr.memberId,
payoutsBbf.totalPyts
FROM
users usr
LEFT JOIN
(SELECT
pyt.member_id AS mmb_id,
SUM(pyt.amount) AS totalPyts
FROM
payout pyt
WHERE
pyt.payoutPeriod < '2018-01-01'
GROUP BY pyt.member_id) AS payoutsBbf ON usr.id = payoutsBbf.mmb_id
我希望在QueryDsl SQL
中编写它,并且将子查询保持连接到主表users
coz几乎是重要的,因为这只是整个复杂查询的一个片段。
LEFT JOIN x ON
部分SELECT payoutBbf.totalPyts
部分中的子查询别名我认为这对你有用。虽然有点hacky:
SQLQueryFactory sqlqf; // Should be @Autowired
QUsers qusers = new QUsers();
QPayouts qpayouts = new QPayouts();
Expression<Long> memberId = ExpressionUtils.as(qpayouts.memberId, "mmb_id");
Expression<Double> totalPayouts = ExpressionUtils.as(qpayouts.amount.sum(), "totalPayouts");
SQLQuery<Tuple> payoutsBbf = SQLExpressions.select(memberId, totalPayouts)
.from(qpayouts)
.where(qpayouts.payoutPeriod.lt("2018-01-01")) // Use date object
.groupBy(qpayouts.memberId);
final SimplePath<? extends SQLQuery> payoutsBBfPath = Expressions.path(payoutsBBfPath.getClass(), "payoutsBbf");
List<Tuple> fetch = sqlqf.select(
qusers.memberId,
Expressions.path(payoutsBbf.getClass(), new PathMetadata(payoutsBBfPath, "totalPayouts", PathType.PROPERTY))
)
.from(qusers)
.leftJoin(payoutsBbf, payoutsBBfPath)
.addJoinFlag(" on payoutsBbf.mmb_id = users.id", JoinFlag.Position.BEFORE_CONDITION)
.fetch();
请注意使用JoinFlag指定连接列,使用定义为payoutsBbf
的别名。另请注意使用Expressions.path()
指定select()
部分中的子列
我就是这样做的:
final StringPath payoutsBbf = stringPath("payoutsBbf");
final String mmbId = "mmb_id";
final String totalPyts = "totalPyts";
sqlQueryFactory.select(users.memberId, stringPath(payoutsBbf, totalPyts))
.from(users).leftJoin(
sqlQueryFactory.select(payout.member_id.as(mmbId), member_id.amount.sum().as(totalPyts))
.from(payout).where(payout.payoutPeriod.lt("2018-01-01")).groupBy(payout.member_id),
payoutsBbf
).on(users.id.eq(stringPath(payoutsBbf, mmbId))).fetch();