public abstract class QueryProviderImpl extends Object implements QueryProvider
QueryProvider
.
Derived class needs to implement QueryProvider.executeQuery(net.hydromatic.linq4j.Queryable<T>)
.
Modifier and Type | Class and Description |
---|---|
static class |
QueryProviderImpl.QueryableImpl<T>
Binds an expression to this query provider.
|
Constructor and Description |
---|
QueryProviderImpl()
Creates a QueryProviderImpl.
|
Modifier and Type | Method and Description |
---|---|
<T> Queryable<T> |
createQuery(Expression expression,
Class<T> rowType)
Constructs a
Queryable object that can evaluate the query
represented by a specified expression tree. |
<T> Queryable<T> |
createQuery(Expression expression,
Type rowType)
Constructs a
Queryable object that can evaluate the query
represented by a specified expression tree. |
<T> T |
execute(Expression expression,
Class<T> type)
Executes the query represented by a specified expression tree.
|
<T> T |
execute(Expression expression,
Type type)
Executes the query represented by a specified expression tree.
|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
executeQuery
public <T> Queryable<T> createQuery(Expression expression, Class<T> rowType)
QueryProvider
Queryable
object that can evaluate the query
represented by a specified expression tree.
NOTE: The RawQueryable.getExpression()
property of the returned Queryable
object is equal to
expression
.
createQuery
in interface QueryProvider
T
- Row typeexpression
- ExpressionrowType
- Row typepublic <T> Queryable<T> createQuery(Expression expression, Type rowType)
QueryProvider
Queryable
object that can evaluate the query
represented by a specified expression tree. The row type may contain
generic information.createQuery
in interface QueryProvider
T
- Row typeexpression
- ExpressionrowType
- Row typepublic <T> T execute(Expression expression, Class<T> type)
QueryProvider
This method executes queries that return a single value
(instead of an enumerable sequence of values). Expression trees that
represent queries that return enumerable results are executed when the
Queryable
object that contains the expression tree is
enumerated.
The Queryable standard query operator methods that return singleton
results call execute
. They pass it a
MethodCallExpression
that represents a linq4j query.
execute
in interface QueryProvider
public <T> T execute(Expression expression, Type type)
QueryProvider
execute
in interface QueryProvider
Copyright © 2012-2014 Julian Hyde. All Rights Reserved.