org.mybatis.dynamic.sql.select.aggregate

Class AbstractAggregate<T extends AbstractAggregate<T>>

java.lang.Object

org.mybatis.dynamic.sql.select.aggregate.AbstractAggregate<T>

Type Parameters:

T - the subclass type

All Implemented Interfaces:

BasicColumn

Direct Known Subclasses:

Avg, Count, CountDistinct, Max, Min, Sum

public abstract class AbstractAggregate<T extends AbstractAggregate<T>>
extends Object
implements BasicColumn

This class is the base class for aggregate functions.

Author:

Jeff Butler

Field Summary

Fields

Modifier and Type	Field and Description
protected String	alias
protected BasicColumn	column

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractAggregate(BasicColumn column)

Method Summary

Modifier and Type	Method and Description
Optional<String>	alias() Returns the columns alias if one has been specified.
T	as(String alias) Returns a new instance of a BasicColumn with the alias set.
protected abstract T	copy()
protected abstract String	render(String columnName) Calculate the rendered string for the select list.
String	renderWithTableAlias(TableAliasCalculator tableAliasCalculator) Returns the name of the item aliased with a table name if appropriate.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.mybatis.dynamic.sql.BasicColumn

columnList, renderWithTableAndColumnAlias

Field Detail

column

protected BasicColumn column

alias

protected String alias

Constructor Detail

AbstractAggregate

protected AbstractAggregate(BasicColumn column)

Method Detail

alias

public Optional<String> alias()

Description copied from interface: BasicColumn

Returns the columns alias if one has been specified.

Specified by:

alias in interface BasicColumn

Returns:

the column alias

renderWithTableAlias

public String renderWithTableAlias(TableAliasCalculator tableAliasCalculator)

Description copied from interface: BasicColumn

Returns the name of the item aliased with a table name if appropriate. For example, "a.foo". This is appropriate for where clauses and order by clauses.

Specified by:

renderWithTableAlias in interface BasicColumn

Parameters:

tableAliasCalculator - the table alias calculator for the current renderer

Returns:

the item name with the table alias applied

as

public T as(String alias)

Description copied from interface: BasicColumn

Returns a new instance of a BasicColumn with the alias set.

Specified by:

as in interface BasicColumn

Parameters:

alias - the column alias to set

Returns:

new instance with alias set

copy

protected abstract T copy()

render

protected abstract String render(String columnName)

Calculate the rendered string for the select list.

Parameters:

columnName - the calculated column name. It will have the table alias already applied if applicable.

Returns:

the rendered string for the select list