LogicalUnion (OpenJPA Parent POM 3.1.0 API)

java.lang.Object
- org.apache.openjpa.jdbc.sql.LogicalUnion

All Implemented Interfaces:

SelectExecutor, Union
```
public class LogicalUnion
extends Object
implements Union
```
A logical union made up of multiple distinct selects whose results are combined in memory.

Author:

Abe White

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static interface`	`LogicalUnion.Selector` A callback used to create the selects in a SQL union.
`class`	`LogicalUnion.UnionSelect` A select that is part of a logical union.

Field Summary

Fields
Modifier and Type Field and Description

protected BitSet desc

protected DBDictionary dict

protected ClassMapping[] mappings

protected LogicalUnion.UnionSelect[] sels

Fields
Modifier and Type	Field and Description
`protected BitSet`	`desc`
`protected DBDictionary`	`dict`
`protected ClassMapping[]`	`mappings`
`protected LogicalUnion.UnionSelect[]`	`sels`

Constructor Summary

Constructors
Modifier	Constructor and Description
	`LogicalUnion(JDBCConfiguration conf, int sels)` Constructor.
`protected`	`LogicalUnion(JDBCConfiguration conf, int sels, Select[] seeds)` Delegate constructor.
	`LogicalUnion(JDBCConfiguration conf, Select[] seeds)` Constructor used to seed the internal selects.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`abortUnion()` Force the use of a series of standard selects rather than a true UNION.
`Result`	`execute(JDBCStore store, JDBCFetchConfiguration fetch)` Execute this select in the context of the given store manager.
`Result`	`execute(JDBCStore store, JDBCFetchConfiguration fetch, int lockLevel)` Execute this select in the context of the given store manager.
`boolean`	`getAutoDistinct()` Whether to automatically make results distinct when relational joins would otherwise introduce duplicates.
`JDBCConfiguration`	`getConfiguration()` Return the select configuration.
`int`	`getCount(JDBCStore store)` Return the number of instances matching this select.
`DBDictionary`	`getDBDictionary()`
`int`	`getExpectedResultCount()` The expected result count for the query.
`int`	`getJoinSyntax()` The join syntax for this select, as one of the syntax constants from `JoinSyntaxes`.
`String`	`getOrdering()` Get the union-level ordering, if any.
`Select[]`	`getSelects()` Return the selects that make up this union.
`SQLBuffer`	`getSQL()` Get the buffer if it has been computed by a previous call to `SelectExecutor.toSelect(boolean, JDBCFetchConfiguration)`, if any.
`boolean`	`hasMultipleSelects()` Affirm if this receiver requires more than one selects to fetch its data.
`boolean`	`isDistinct()` Whether this is a SELECT DISTINCT / UNION ALL.
`boolean`	`isLRS()` Whether the result of this select should be treated as a large result set.
`boolean`	`isUnion()` Whether this is a true UNION, rather than a logical combination of independent selects.
`protected LogicalUnion.UnionSelect`	`newUnionSelect(SelectImpl seed, int pos)` Create a new union select with the given delegate and union position.
`void`	`select(Union.Selector selector)` Select data using the given selector.
`void`	`setAutoDistinct(boolean distinct)` Whether to automatically make results distinct when relational joins would otherwise introduce duplicates.
`void`	`setDistinct(boolean distinct)` Whether this is a SELECT DISTINCT / UNION ALL.
`void`	`setExpectedResultCount(int expectedResultCount, boolean force)` The expected result count for the query.
`void`	`setJoinSyntax(int syntax)` The join syntax for this select, as one of the syntax constants from `JoinSyntaxes`.
`void`	`setLRS(boolean lrs)` Whether the result of this select should be treated as a large result set.
`boolean`	`supportsLocking()` Whether this select can be executed for update.
`boolean`	`supportsRandomAccess(boolean forUpdate)` Return whether this select can support a random access result set type.
`SQLBuffer`	`toSelect(boolean forUpdate, JDBCFetchConfiguration fetch)` Return this select as a SQL statement formatted for the current dictionary.
`SQLBuffer`	`toSelectCount()` Return this select as a COUNT SQL statement formatted for the current dictionary.
`String`	`toString()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - sels
```
protected final LogicalUnion.UnionSelect[] sels
```
  - dict
```
protected final DBDictionary dict
```
  - mappings
```
protected final ClassMapping[] mappings
```
  - desc
```
protected final BitSet desc
```
- Constructor Detail
  - LogicalUnion
```
public LogicalUnion(JDBCConfiguration conf,
                    int sels)
```
    Constructor.
    
    Parameters:
    
    conf - system configuration
    
    sels - the number of SQL selects to union together
  - LogicalUnion
```
public LogicalUnion(JDBCConfiguration conf,
                    Select[] seeds)
```
    Constructor used to seed the internal selects.
  - LogicalUnion
```
protected LogicalUnion(JDBCConfiguration conf,
                       int sels,
                       Select[] seeds)
```
    Delegate constructor.
- Method Detail
  - newUnionSelect
```
protected LogicalUnion.UnionSelect newUnionSelect(SelectImpl seed,
                                                  int pos)
```
    Create a new union select with the given delegate and union position.
  - getSelects
```
public Select[] getSelects()
```
    Description copied from interface: Union
    
    Return the selects that make up this union.
    
    Specified by:
    
    getSelects in interface Union
  - isUnion
```
public boolean isUnion()
```
    Description copied from interface: Union
    
    Whether this is a true UNION, rather than a logical combination of independent selects.
    
    Specified by:
    
    isUnion in interface Union
  - abortUnion
```
public void abortUnion()
```
    Description copied from interface: Union
    
    Force the use of a series of standard selects rather than a true UNION.
    
    Specified by:
    
    abortUnion in interface Union
  - getOrdering
```
public String getOrdering()
```
    Description copied from interface: Union
    
    Get the union-level ordering, if any.
    
    Specified by:
    
    getOrdering in interface Union
  - getConfiguration
```
public JDBCConfiguration getConfiguration()
```
    Description copied from interface: SelectExecutor
    
    Return the select configuration.
    
    Specified by:
    
    getConfiguration in interface SelectExecutor
  - getDBDictionary
```
public DBDictionary getDBDictionary()
```
  - toSelect
```
public SQLBuffer toSelect(boolean forUpdate,
                          JDBCFetchConfiguration fetch)
```
    Description copied from interface: SelectExecutor
    
    Return this select as a SQL statement formatted for the current dictionary.
    
    Specified by:
    
    toSelect in interface SelectExecutor
  - getSQL
```
public SQLBuffer getSQL()
```
    Description copied from interface: SelectExecutor
    
    Get the buffer if it has been computed by a previous call to SelectExecutor.toSelect(boolean, JDBCFetchConfiguration), if any.
    
    Specified by:
    
    getSQL in interface SelectExecutor
  - toSelectCount
```
public SQLBuffer toSelectCount()
```
    Description copied from interface: SelectExecutor
    
    Return this select as a COUNT SQL statement formatted for the current dictionary.
    
    Specified by:
    
    toSelectCount in interface SelectExecutor
  - getAutoDistinct
```
public boolean getAutoDistinct()
```
    Description copied from interface: SelectExecutor
    
    Whether to automatically make results distinct when relational joins would otherwise introduce duplicates.
    
    Specified by:
    
    getAutoDistinct in interface SelectExecutor
  - setAutoDistinct
```
public void setAutoDistinct(boolean distinct)
```
    Description copied from interface: SelectExecutor
    
    Whether to automatically make results distinct when relational joins would otherwise introduce duplicates.
    
    Specified by:
    
    setAutoDistinct in interface SelectExecutor
  - isDistinct
```
public boolean isDistinct()
```
    Description copied from interface: SelectExecutor
    
    Whether this is a SELECT DISTINCT / UNION ALL.
    
    Specified by:
    
    isDistinct in interface SelectExecutor
  - setDistinct
```
public void setDistinct(boolean distinct)
```
    Description copied from interface: SelectExecutor
    
    Whether this is a SELECT DISTINCT / UNION ALL.
    
    Specified by:
    
    setDistinct in interface SelectExecutor
  - isLRS
```
public boolean isLRS()
```
    Description copied from interface: SelectExecutor
    
    Whether the result of this select should be treated as a large result set.
    
    Specified by:
    
    isLRS in interface SelectExecutor
  - setLRS
```
public void setLRS(boolean lrs)
```
    Description copied from interface: SelectExecutor
    
    Whether the result of this select should be treated as a large result set.
    
    Specified by:
    
    setLRS in interface SelectExecutor
  - getExpectedResultCount
```
public int getExpectedResultCount()
```
    Description copied from interface: SelectExecutor
    
    The expected result count for the query.
    
    Specified by:
    
    getExpectedResultCount in interface SelectExecutor
  - setExpectedResultCount
```
public void setExpectedResultCount(int expectedResultCount,
                                   boolean force)
```
    Description copied from interface: SelectExecutor
    
    The expected result count for the query.
    
    Specified by:
    
    setExpectedResultCount in interface SelectExecutor
    
    force - if false, the count will be discarded if this select has any to-many eager joins that would throw off the result count
  - getJoinSyntax
```
public int getJoinSyntax()
```
    Description copied from interface: SelectExecutor
    
    The join syntax for this select, as one of the syntax constants from JoinSyntaxes.
    
    Specified by:
    
    getJoinSyntax in interface SelectExecutor
  - setJoinSyntax
```
public void setJoinSyntax(int syntax)
```
    Description copied from interface: SelectExecutor
    
    The join syntax for this select, as one of the syntax constants from JoinSyntaxes.
    
    Specified by:
    
    setJoinSyntax in interface SelectExecutor
  - supportsRandomAccess
```
public boolean supportsRandomAccess(boolean forUpdate)
```
    Description copied from interface: SelectExecutor
    
    Return whether this select can support a random access result set type.
    
    Specified by:
    
    supportsRandomAccess in interface SelectExecutor
  - supportsLocking
```
public boolean supportsLocking()
```
    Description copied from interface: SelectExecutor
    
    Whether this select can be executed for update.
    
    Specified by:
    
    supportsLocking in interface SelectExecutor
  - hasMultipleSelects
```
public boolean hasMultipleSelects()
```
    Description copied from interface: SelectExecutor
    
    Affirm if this receiver requires more than one selects to fetch its data.
    
    Specified by:
    
    hasMultipleSelects in interface SelectExecutor
  - getCount
```
public int getCount(JDBCStore store)
             throws SQLException
```
    Description copied from interface: SelectExecutor
    
    Return the number of instances matching this select.
    
    Specified by:
    
    getCount in interface SelectExecutor
    
    Throws:
    
    SQLException
  - execute
```
public Result execute(JDBCStore store,
                      JDBCFetchConfiguration fetch)
               throws SQLException
```
    Description copied from interface: SelectExecutor
    
    Execute this select in the context of the given store manager.
    
    Specified by:
    
    execute in interface SelectExecutor
    
    Throws:
    
    SQLException
  - execute
```
public Result execute(JDBCStore store,
                      JDBCFetchConfiguration fetch,
                      int lockLevel)
               throws SQLException
```
    Description copied from interface: SelectExecutor
    
    Execute this select in the context of the given store manager.
    
    Specified by:
    
    execute in interface SelectExecutor
    
    Throws:
    
    SQLException
  - select
```
public void select(Union.Selector selector)
```
    Description copied from interface: Union
    
    Select data using the given selector.
    
    Specified by:
    
    select in interface Union
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Class LogicalUnion

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

sels

dict

mappings

desc

Constructor Detail

LogicalUnion

LogicalUnion

LogicalUnion

Method Detail

newUnionSelect

getSelects

isUnion

abortUnion

getOrdering

getConfiguration

getDBDictionary

toSelect

getSQL

toSelectCount

getAutoDistinct

setAutoDistinct

isDistinct

setDistinct

isLRS

setLRS

getExpectedResultCount

setExpectedResultCount

getJoinSyntax

setJoinSyntax

supportsRandomAccess

supportsLocking

hasMultipleSelects

getCount

execute

execute

select

toString