com.healthmarketscience.sqlbuilder

Class CommonTableExpression

java.lang.Object

com.healthmarketscience.common.util.AppendeeObject

com.healthmarketscience.sqlbuilder.SqlObject

com.healthmarketscience.sqlbuilder.CommonTableExpression

All Implemented Interfaces:

Appendee, Verifiable<CommonTableExpression>

public class CommonTableExpression
extends SqlObject
implements Verifiable<CommonTableExpression>

Outputs the Common Table Expression (CTE) definition as part of a "WITH " clause. Useable with queries which extend BaseCTEQuery.

A CommonTableExpression creates a pseudo Table and pseudo Columns which can subsequently be used in the queries to which this definition applies.

Author:

James Ahlborn

See Also:

"SQL 99"

Field Summary

Fields inherited from class com.healthmarketscience.sqlbuilder.SqlObject

ALL_SYMBOL, NULL_VALUE, QUESTION_MARK

Constructor Summary

Constructors

Constructor and Description
CommonTableExpression(String name)

Method Summary

Modifier and Type	Method and Description
Column	addColumn(String name) Adds a new column with the given name to this CTE and returns the pseudo Column instane.
void	appendTo(AppendableExt app) Appends this object to the given AppendableExt.
protected void	collectSchemaObjects(ValidationContext vContext) Used during Query.validate() calls to collect the dbschema objects referenced in a query.
Column	findColumn(String name) Returns a previously defined pseudo Column from this CTE definition with the given name, or null if one cannot be found.
Table	getTable() Returns the pseudo Table instance for this CTE.
CommonTableExpression	setQuery(Object query) Sets the CTE definition query.
CommonTableExpression	setTableAlias(String alias) Sets the pseudo Table alias for use by the pseudo Columns when used in subsequent queries.
CommonTableExpression	validate() Runs validation on this verifiable object.
void	validate(ValidationContext vContext) Runs validation on this verifiable object using a previously collected ValidationContext.

Methods inherited from class com.healthmarketscience.sqlbuilder.SqlObject

collectSchemaObjects, doValidate, toString

Methods inherited from class com.healthmarketscience.common.util.AppendeeObject

toString, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

CommonTableExpression

public CommonTableExpression(String name)

Parameters:

name - name of this common table expression.

Method Detail

getTable

public Table getTable()

Returns the pseudo Table instance for this CTE.

addColumn

public Column addColumn(String name)

Adds a new column with the given name to this CTE and returns the pseudo Column instane.

findColumn

public Column findColumn(String name)

Returns a previously defined pseudo Column from this CTE definition with the given name, or null if one cannot be found.

setTableAlias

public CommonTableExpression setTableAlias(String alias)

Sets the pseudo Table alias for use by the pseudo Columns when used in subsequent queries.

Note, setting this is optional. If unset, a unique alias will be generated for this CTE when it is added to a BaseCTEQuery instance.

setQuery

public CommonTableExpression setQuery(Object query)

Sets the CTE definition query. Object -> SqlObject conversions handled by Converter.toCustomSqlObject(Object).

collectSchemaObjects

protected void collectSchemaObjects(ValidationContext vContext)

Description copied from class: SqlObject

Used during Query.validate() calls to collect the dbschema objects referenced in a query. Any subclass of this class should add all referenced tables and columns to the appropriate collections.

Specified by:

collectSchemaObjects in class SqlObject

Parameters:

vContext - handle to the current validation context

appendTo

public void appendTo(AppendableExt app)
              throws IOException

Description copied from interface: Appendee

Appends this object to the given AppendableExt. Called by an AppendableExt when a request is made to append an instance of Appendee.

Specified by:

appendTo in interface Appendee

Overrides:

appendTo in class AppendeeObject

Parameters:

app - the AppendableExt to which this class should append itself

Throws:

IOException - if the append fails

validate

public final CommonTableExpression validate()
                                     throws ValidationException

Description copied from interface: Verifiable

Runs validation on this verifiable object.

Specified by:

validate in interface Verifiable<CommonTableExpression>

Returns:

a handle to this instance

Throws:

ValidationException

validate

public void validate(ValidationContext vContext)
              throws ValidationException

Description copied from interface: Verifiable

Runs validation on this verifiable object using a previously collected ValidationContext.

In general, this method will only be called internally, not by users.

Specified by:

validate in interface Verifiable<CommonTableExpression>

Parameters:

vContext - handle to the current, filled-in validation context

Throws:

ValidationException