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SQUERYLORM ! "#$%&#"#!'() $(*%)
!"#$ %&'()* e-Legion Ltd., 20111
ORM
Query q = entityManager.createQuery( "SELECT AVG(g.scoreInPercentage) FROM Grades g where g.subjectId = :subjectId");
q.setParameter(1, mathId); Number avg = (Number) q.getSingleResult();
avg.floatValue();
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ORM
Query q = entityManager.createQuery( "SELECT AVG(g.scoreInPercentage) FROM Grades g where g.subjectId = :subjectId");
q.setParameter(1, mathId); Number avg = (Number) q.getSingleResult();
avg.floatValue();
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TYPE SAFE ORM (JPA 2)
EntityManager em = ...CriteriaBuilder qb = em.getCriteriaBuilder();
CriteriaQuery<Person> c = qb.createQuery(Person.class);Root<Person> p = c.from(Person.class);Predicate condition = qb.gt(p.get(Person_.age), 20);c.where(condition);TypedQuery<Person> q = em.createQuery(c); List<Person> olderThan20s = q.getResultList();
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SQUERYL
ORM
SQL-+%,%-./0 DSL ,$1 23+4%!%&
564%731 6(+(23*(1
8#.9:# '%,3, -%$9:# ,#$3
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TYPE SAFE ORM (JPA 2)
EntityManager em = ...CriteriaBuilder qb = em.getCriteriaBuilder();
CriteriaQuery<Person> c = qb.createQuery(Person.class);Root<Person> p = c.from(Person.class);Predicate condition = qb.gt(p.get(Person_.age), 20);c.where(condition);TypedQuery<Person> q = em.createQuery(c); List<Person> olderThan20s = q.getResultList();
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SQUERYL
val olderThan20s = people.where(_.age gt 20)
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SQUERYL
val olderThan20s =
from (people) ( p => select (p)where (p.age gt 20)
)
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!"#!$%
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!"#!$%
;.(*(3$(23*(1
<43.23'*((
5=#)3
Insert
Select
Update
Delete
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&#&'&()&*('&+
import org.squeryl.SessionFactory import java.sql.DriverManager._
Class.forName("org.h2.Driver") SessionFactory.concreteFactory = Some { ()=> Session.create(
getConnection("jdbc:h2:mem:"),new H2Adapter
) }
“>3(&.31” ?3-4('3
;!+%$92@06# ConnectionPool (DBCP, BoneCP)
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,-(#*(.'&&
transaction { ... }
&!#7,3 .3"(.3#6 .%&@A 643.23'*(A ( '%))(6(6 & '%.*#
inTransaction { ... }
.("#7% .# ,#$3#6, #!$( (!+%$92@#6!1 &.@64( ,4@7%0 643.23'*((
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"/01((PrimitiveTypeMode)
case class User( id: Long = 0, @Column(length = 256) email: String, name: String, rating: Int = 0, ) extends KeyedEntity[Long]
Plain Old Scala Object ()%B.% case)563.,346./# 6(+/ ,$1 +%$#0C%$1 )%7@6 -/69 var ($( val8%B.% @'32369 432)#4, ()1 !6%$-*3 & -32#>3!$#,%&369 KeyedEntity .# %-1236#$9.%
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"/01((CustomTypeMode)
5$%B./# '$3!!/ ,$1 +%$#0 8%7@6 &'$A"369 & !#-1 &3$(,3*(A, etc
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"/01(
object MySchema extends Schema { val users = table[User]
on(users) { u => declare( u.id is (autoIncremented), u.email is (unique) ) } }
transaction { MySchema.create }
<3-$(*/D743.("#.(15&12(
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INSERT
import MySchema._ val vasya = users.insert(new User("[email protected]", "Vasya"))
users.insert(List(user1, user2))
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SELECT
from(users) ( u => select(u) where(u.name like “%Vasya%”) )
from(users) ( u => select(u.id, u.email) orderBy(u.id asc) )
users.where( _.rating.~ >= 0)
//Option[User]users.lookup(1)
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FULL UPDATE
//используем copy//поскольку все поля immutable
val updatedVasya = vasya.copy(rating = vasya.rating + 1)
users.update(updatedVasya)
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PARTIAL UPDATE
val updated = update(users) ( u => set(u.rating := u.rating.~ + 1) where(u.name like "%Vasya%") )
println("%s Vasyas rated" format updated)
~. "6%-/ .# +@6369 Int.+ ( SQL ‘+’
&)#!6% ~. )%B.% (!+%$92%&369 u.rating plus 1
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DELETE
users.delete(1)
val deleted = users.deleteWhere( u => u.rating.~ < 0 )
println("%s users deleted" format deleted)
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2$&3(01"+ 2()450
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2$&3(01"+ 2()450
5%!63&./# 23+4%!/
Group By ( 374#73*(1
Joins
Relations
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COMPOSITE SELECT
val rated = users.where( _.rating.~ >= 0)
val vasyasRated = from(rated) ( u => select(u) where(u.name like “%Vasya%”) )
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NESTED SELECT
val rated = users.where( _.rating.~ >= 0)
val vasyasRated = from(rated) ( u => select(u) where(u.id in
from(rated) (r => select(r.id))
) )
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067 SELECT
C%!643.(".31 &/-%4'3
from(users) ( u => ... ).page(offset, pageLength)
Distinct
from(users) ( u => ... ).distinct
ForUpdate
from(users) ( u => ... ).forUpdate
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(3-03('&+
val ratingDistribution = from(users) ( u =>
groupBy(u.rating)compute(count(u.id))
)
ratingDistribution foreach { r=>println(“%s: %s” format (r.key, r.measures))
}
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JOIN
from(users, posts) ( (u,p) =>select(u.name, p)where(u.id === p.userId)
)
from(users, avatars.leftOuter) ( (u,a) =>select(u, a.url)on(u.id === a.map(_.userId))
)
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RELATIONS
object MySchema extends Schema { val users = table[User] val posts = table[Post] val userPosts =
oneToManyRelation(users, posts) via ( (u,p) =>u.id === p.userId
) }
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(STATELESS) RELATIONS
case class User (....) extends KeyedEntity[Long] { //OneToMany[Post] < Querylazy val posts = MySchema.userPosts.left(this)
}
case class User (....) extends KeyedEntity[Long] { //ManyToOne[User] < Querylazy val user = MySchema.userPosts.right(this)
}
val user = users.lookup(1).getOrElse(error(“user not found”))
for (p <- user.posts) println(p.title)
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STATEFUL RELATIONS
case class User (....) extends KeyedEntity[Long] {
//StatefulOneToMany[Post] < Iterable[Post]lazy val posts = MySchema.userPosts.leftStateful(this)
}
case User (....) extends KeyedEntity[Long] {
//StetefulManyToOne[User]lazy val user = MySchema.userPosts.rightStateful(this)
}
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#02!",(,.&
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#02!",(,.&
Compile-time VoodoocreateEqualityExpressionWithLastAccessedFieldReferenceAndConstant
>#6 UNION
5$(:'%) @)./0 DSLwhere ( u.name === stringOpt.? ) //работает
where ( u.flag === boolOpt.? ) //не работает
not(not(u.flag)).inhibitWhen(boolOpt != Some(true)) andnot(u.flag).inhibitWhen(boolOpt != Some(false))
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$!8-!"%?
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"8("&9!
email: [email protected]
email: [email protected]
www: http://digal.github.com/
twitter: @digal
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