Package de.businesscode.bcdui.wrs.load

Class SqlFromSubSelect

java.lang.Object

de.businesscode.bcdui.wrs.load.SqlFromSubSelect

public class SqlFromSubSelect
extends Object

Takes a single wrq:Select (formally a "sub-select") and turns it into a SQLStatementWithParams Each select taking part in UNIONs or being a sub-select is represented by an instance of this class. It uses WrqInfo to collect all necessary information from the WRQ XML There is a 1:1 relationship between SqlFromSubSelect and WrqInfo

Field Summary

Fields

Modifier and Type	Field	Description
protected Map<String,WrqBindingSet>	bindingSetForWrqAlias	These BindingSets are our main BindingSet and all joined ones, i.e, all listed in our wrq:From
protected final SqlFromSubSelect	parent
protected WrqBindingSetFromDerivedTable	representingBindingSet	A virtual BindingSet representing the result set created by this sub-select
protected Set<StandardBindingSet>	resolvedBindingSets	All Standard BindingSets, which we or any of our sub-selects are using
protected int	rowEnd
protected int	rowStart
protected final Element	selectElem
protected SQLStatementWithParams	selectStatement
protected final WrqInfo	wrqInfo
protected final WrqQueryBuilder	wrqQueryBuilder

Constructor Summary

Constructors

Constructor	Description
SqlFromSubSelect(WrqQueryBuilder wrqQueryBuilder, SqlFromSubSelect parent, Element selectElem)	We are initialized for a full-select (SELECTSs connected with SET operators).

Method Summary

Modifier and Type	Method	Description
protected void	addBindingSetForWrqAlias(String wrqAlias, WrqBindingSet bindingSet)	Set the BindingSet for a user-provided table expression alias
protected void	createSelectStatement()	Handles a "select-statement", i.e. a complete select
protected void	generateFromClause(WrqInfo wrqInfo, SQLStatementWithParams sqlStatement)	Generates 'FROM' and the tables with their join expression
protected void	generateGroupingClause(WrqInfo wrqInfo, SQLStatementWithParams sqlStatement)	Generates Grouping clause
protected void	generateHavingClause(WrqInfo wrqInfo, SQLStatementWithParams sqlStatement)	Generates Having SQL clause
protected void	generateOffsetFetchClause(WrqInfo wrqInfo, SQLStatementWithParams sqlStatement)	Optionally append 'OFFSET 10 FETCH NEXT 20 ROWS ONLY' for pagination
protected void	generateOrderClause(WrqInfo wrqInfo, SQLStatementWithParams sqlStatement)	Generates Order-By clause
protected void	generateSelectClause(WrqInfo wrqInfo, SQLStatementWithParams sqlStatement)	Generates 'SELECT' plus the select list
protected void	generateWhereClause(WrqInfo wrqInfo, SQLStatementWithParams sqlStatement)	Generates 'WHERE' plus the filter
List<Element>	getBoundVariables()
SqlFromSubSelect	getParent()	Access to parent select, which may be null This is used, for example, to look up referenced columns
WrqBindingSet	getRepresentingBindingSet()	A BindingSet representing our result set as if we were a bnd:BindingSet
Set<StandardBindingSet>	getResolvedBindingSets()
LinkedList<WrsBindingItem>	getSelectedBindingItems()
Element	getSelectElem()
SQLStatementWithParams	getSelectStatement()
WrqInfo	getWrqInfo()
WrqQueryBuilder	getWrqQueryBuilder()	Access to the current overall query, there is only one per Wrq
BindingItem	resolveBindingItemFromScope(String bRef)	Retrieve a BindingItem bRef with alias from the current scope, i.e, the local wrq:From or any wrq:From from outer selects or CTEs
WrqBindingSet	resolveBindingSetFromScope(String wrqAlias)	Get the (Virtual)BindingSet for a user-provided table expression wrq alias.

Methods inherited from class java.lang.Object

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

Field Details

selectElem

protected final Element selectElem

wrqQueryBuilder

protected final WrqQueryBuilder wrqQueryBuilder

parent

protected final SqlFromSubSelect parent

wrqInfo

protected final WrqInfo wrqInfo

rowStart

protected int rowStart

rowEnd

protected int rowEnd

resolvedBindingSets

protected Set<StandardBindingSet> resolvedBindingSets

All Standard BindingSets, which we or any of our sub-selects are using

representingBindingSet

protected WrqBindingSetFromDerivedTable representingBindingSet

A virtual BindingSet representing the result set created by this sub-select

bindingSetForWrqAlias

protected Map<String,WrqBindingSet> bindingSetForWrqAlias

These BindingSets are our main BindingSet and all joined ones, i.e, all listed in our wrq:From

selectStatement

protected SQLStatementWithParams selectStatement

Constructor Details

SqlFromSubSelect

public SqlFromSubSelect(WrqQueryBuilder wrqQueryBuilder,
 SqlFromSubSelect parent,
 Element selectElem)
                 throws Exception

We are initialized for a full-select (SELECTSs connected with SET operators).

Parameters:

wrqQueryBuilder -

selectElem -

Throws:

Exception

Method Details

createSelectStatement

protected void createSelectStatement()
                              throws Exception

Handles a "select-statement", i.e. a complete select

Throws:

Exception

See Also:

• ISqlGenerator.getSelectStatement()

generateSelectClause

protected void generateSelectClause(WrqInfo wrqInfo,
 SQLStatementWithParams sqlStatement)
                             throws BindingNotFoundException

Generates 'SELECT' plus the select list

Throws:

BindingNotFoundException

generateFromClause

protected void generateFromClause(WrqInfo wrqInfo,
 SQLStatementWithParams sqlStatement)
                           throws BindingException

Generates 'FROM' and the tables with their join expression

Throws:

BindingException

generateWhereClause

protected void generateWhereClause(WrqInfo wrqInfo,
 SQLStatementWithParams sqlStatement)
                            throws Exception

Generates 'WHERE' plus the filter

Throws:

XPathExpressionException

BindingException

Exception

generateGroupingClause

protected void generateGroupingClause(WrqInfo wrqInfo,
 SQLStatementWithParams sqlStatement)
                               throws Exception

Generates Grouping clause

Throws:

Exception

generateHavingClause

protected void generateHavingClause(WrqInfo wrqInfo,
 SQLStatementWithParams sqlStatement)
                             throws Exception

Generates Having SQL clause

Parameters:

wrqInfo -

sqlStatement -

Throws:

XPathExpressionException

BindingException

Exception

generateOrderClause

protected void generateOrderClause(WrqInfo wrqInfo,
 SQLStatementWithParams sqlStatement)
                            throws BindingNotFoundException

Generates Order-By clause

Throws:

BindingNotFoundException

generateOffsetFetchClause

protected void generateOffsetFetchClause(WrqInfo wrqInfo,
 SQLStatementWithParams sqlStatement)
                                  throws BindingNotFoundException

Optionally append 'OFFSET 10 FETCH NEXT 20 ROWS ONLY' for pagination

Parameters:

wrqInfo -

sqlStatement -

Throws:

BindingNotFoundException

getBoundVariables

public List<Element> getBoundVariables()

getSelectedBindingItems

public LinkedList<WrsBindingItem> getSelectedBindingItems()

getRepresentingBindingSet

public WrqBindingSet getRepresentingBindingSet()
                                        throws Exception

A BindingSet representing our result set as if we were a bnd:BindingSet

Returns:

Throws:

Exception

getWrqInfo

public WrqInfo getWrqInfo()

getResolvedBindingSets

public Set<StandardBindingSet> getResolvedBindingSets()

getSelectStatement

public SQLStatementWithParams getSelectStatement()

resolveBindingSetFromScope

public WrqBindingSet resolveBindingSetFromScope(String wrqAlias)
                                         throws BindingNotFoundException

Get the (Virtual)BindingSet for a user-provided table expression wrq alias. Can be a BindingSet or a sub-select acting as a table expression. It can also be a (Virtual)BindingSet in an outer Select or a Cte.

Parameters:

wrqAlias - the wrq table alias

Returns:

Throws:

BindingNotFoundException

resolveBindingItemFromScope

public BindingItem resolveBindingItemFromScope(String bRef)
                                        throws BindingNotFoundException

Retrieve a BindingItem bRef with alias from the current scope, i.e, the local wrq:From or any wrq:From from outer selects or CTEs

Parameters:

bRef - including wrq table alias

Returns:

Throws:

BindingNotFoundException

addBindingSetForWrqAlias

protected void addBindingSetForWrqAlias(String wrqAlias,
 WrqBindingSet bindingSet)

Set the BindingSet for a user-provided table expression alias

Parameters:

wrqAlias -

bindingSet -

getWrqQueryBuilder

public WrqQueryBuilder getWrqQueryBuilder()

Access to the current overall query, there is only one per Wrq

Returns:

getParent

public SqlFromSubSelect getParent()

Access to parent select, which may be null This is used, for example, to look up referenced columns

Returns:

getSelectElem

public Element getSelectElem()