Class SubSelect<T>

java.lang.Object

org.tentackle.dbms.dsl.SubSelect<T>

Type Parameters:

T - the java type of the single column returned by the sub-select

All Implemented Interfaces:

Expression<T>, SqlElement

public class SubSelect<T>
extends Object
implements Expression<T>

A sub-select used as a scalar expression.

Author:

harald

Constructor Summary

Constructors

Constructor	Description
SubSelect(Select select, DataType<T> dataType)	Creates a scalar sub-select.

Method Summary

Modifier and Type	Method	Description
int	getColumnCount(Backend backend)	Gets the number of database columns this expression spans.
DataType<T>	getDataType()	Gets the datatype of this expression.
Select	getSelect()	Gets the sub-select.
void	render(RenderContext context, int columnIndex)	Renders a single column of this expression.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface Expression

as, asc, between, desc, eq, eq, ge, ge, getAlias, gt, gt, in, in, isNotNull, isNull, le, le, like, lt, lt, ne, ne, notBetween, notIn, notIn, notLike, render

Constructor Details

SubSelect

public SubSelect(Select select,
 DataType<T> dataType)

Creates a scalar sub-select.

Parameters:

select - the sub-select returning a single row and column

dataType - the datatype, null if untyped

Method Details

getSelect

public Select getSelect()

Gets the sub-select.

Returns:

the sub-select

getDataType

public DataType<T> getDataType()

Description copied from interface: Expression

Gets the datatype of this expression.

Specified by:

getDataType in interface Expression<T>

Returns:

the datatype, null if untyped

getColumnCount

public int getColumnCount(Backend backend)

Description copied from interface: Expression

Gets the number of database columns this expression spans.

Specified by:

getColumnCount in interface Expression<T>

Parameters:

backend - the backend

Returns:

the number of columns, always >= 1

render

public void render(RenderContext context,
 int columnIndex)

Description copied from interface: Expression

Renders a single column of this expression.

Specified by:

render in interface Expression<T>

Parameters:

context - the render context

columnIndex - the column index, 0 for the first column