DTXQuery (Castor JavaDoc)

java.lang.Object
- org.exolab.castor.dtx.DTXQuery

```
public class DTXQuery
extends java.lang.Object
```
A single query that takes OQL query language, reads data from an RDBMS, and returns the results as SAX events. The query can be parameterized, and be re-used with different bound values. There are currently some severe limitations on the contents of the OQL query. The query needs to be a SELECT and must return a single class. However, it can handle multiple returned objects, which are sent to the DocumentHandler as multiple documents. DTXQuery's can't be created on their own; use the DTXEngine to prepare a new query. An additional note: the bind() methods take the parameters in order that they appear, NOT using the number value of the parameter name. So, if you have a query like:
```
... WHERE foo.id = $2 AND bar.name = $1 ... 
```
then the statement bind(1, 12) will bind the value 12 to the first parameter, even though it's named "$2." This may or may not be changed in future releases.
Version:

$Revision: 5961 $ $Date: 2005-12-06 14:55:28 -0700 (Tue, 06 Dec 2005) $

Author:

Evan Prodromou

Field Summary

Fields
Modifier and Type	Field and Description
`protected java.util.HashMap`	`_classes`
`protected ClassMapping`	`_clsMapping`
`protected java.util.HashMap`	`_cols`
`protected DTXEngine`	`_eng`
`protected org.xml.sax.DocumentHandler`	`_handler`
`protected java.util.ArrayList`	`_ids`
`protected int`	`_lastCol`
`protected java.io.PrintWriter`	`_logWriter`
`protected java.lang.String`	`_objName`
`protected java.lang.String`	`_objType`
`protected java.sql.PreparedStatement`	`_stmt`

Constructor Summary

Constructors
Constructor and Description

DTXQuery()

Constructors
Constructor and Description
`DTXQuery()`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`bind(int param, boolean value)` Binds a boolean value to a parameter in the query.
`void`	`bind(int param, double value)` Binds a double value to a parameter in the query.
`void`	`bind(int param, float value)` Binds a float value to a parameter in the query.
`void`	`bind(int param, int value)` Binds an integer value to a parameter in the query.
`void`	`bind(int param, long value)` Binds a long integer value to a parameter in the query.
`void`	`bind(int param, java.lang.Object value)` Binds an Object value to a parameter in the query.
`void`	`bind(int param, java.lang.String value)` Binds an String value to a parameter in the query.
`protected void`	`emitSaxEvents(java.sql.ResultSet rs)`
`protected boolean`	`emitSaxInt(java.sql.ResultSet rs, int idIndex)`
`void`	`execute()` This method executes the query.
`protected void`	`initQuery(ClassMapping clsMapping, QueryExpression expr)`
`protected java.lang.String`	`parseOQL(java.lang.String oql)`
`(package private) void`	`prepare(java.lang.String oql)`
`(package private) void`	`setEngine(DTXEngine eng)`
`void`	`setHandler(org.xml.sax.DocumentHandler handler)` Set the DocumentHandler that will receive the results (as SAX events) for this query.
`void`	`setLogWriter(java.io.PrintWriter logWriter)` Set the log writer.

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

- Field Detail
  - _eng
```
protected DTXEngine _eng
```
  - _handler
```
protected org.xml.sax.DocumentHandler _handler
```
  - _logWriter
```
protected java.io.PrintWriter _logWriter
```
  - _stmt
```
protected java.sql.PreparedStatement _stmt
```
  - _objName
```
protected java.lang.String _objName
```
  - _objType
```
protected java.lang.String _objType
```
  - _clsMapping
```
protected ClassMapping _clsMapping
```
  - _ids
```
protected java.util.ArrayList _ids
```
  - _lastCol
```
protected int _lastCol
```
  - _cols
```
protected java.util.HashMap _cols
```
  - _classes
```
protected java.util.HashMap _classes
```
- Constructor Detail
  - DTXQuery
```
DTXQuery()
```
- Method Detail
  - setHandler
```
public void setHandler(org.xml.sax.DocumentHandler handler)
```
    Set the DocumentHandler that will receive the results (as SAX events) for this query. By default, the query will use the document handler of its DTXEngine. Changing the DocumentHandler in the middle of a query is ill-advised.
    
    Parameters:
    
    handler - The DocumentHandler to use.
  - setLogWriter
```
public void setLogWriter(java.io.PrintWriter logWriter)
```
    Set the log writer.
    
    Parameters:
    
    logWriter - The log writer to use.
  - bind
```
public void bind(int param,
                 java.lang.Object value)
          throws DTXException
```
    Binds an Object value to a parameter in the query.
    
    Parameters:
    
    param - 1-based index of the param (see note above).
    
    value - Object to bind.
    
    Throws:
    
    DTXException
  - bind
```
public void bind(int param,
                 java.lang.String value)
          throws DTXException
```
    Binds an String value to a parameter in the query.
    
    Parameters:
    
    param - 1-based index of the param (see note above).
    
    value - String to bind.
    
    Throws:
    
    DTXException
  - bind
```
public void bind(int param,
                 int value)
          throws DTXException
```
    Binds an integer value to a parameter in the query.
    
    Parameters:
    
    param - 1-based index of the param (see note above).
    
    value - int to bind.
    
    Throws:
    
    DTXException
  - bind
```
public void bind(int param,
                 long value)
          throws DTXException
```
    Binds a long integer value to a parameter in the query.
    
    Parameters:
    
    param - 1-based index of the param (see note above).
    
    value - long integer to bind.
    
    Throws:
    
    DTXException
  - bind
```
public void bind(int param,
                 float value)
          throws DTXException
```
    Binds a float value to a parameter in the query.
    
    Parameters:
    
    param - 1-based index of the param (see note above).
    
    value - float to bind.
    
    Throws:
    
    DTXException
  - bind
```
public void bind(int param,
                 double value)
          throws DTXException
```
    Binds a double value to a parameter in the query.
    
    Parameters:
    
    param - 1-based index of the param (see note above).
    
    value - double to bind.
    
    Throws:
    
    DTXException
  - bind
```
public void bind(int param,
                 boolean value)
          throws DTXException
```
    Binds a boolean value to a parameter in the query.
    
    Parameters:
    
    param - 1-based index of the param (see note above).
    
    value - boolean to bind.
    
    Throws:
    
    DTXException
  - execute
```
public void execute()
             throws DTXException
```
    This method executes the query. All results of the query are sent to the DocumentHandler specified by setHandler() as SAX events.
    
    Throws:
    
    DTXException
  - setEngine
```
void setEngine(DTXEngine eng)
```
  - prepare
```
void prepare(java.lang.String oql)
      throws DTXException
```
    Throws:
    
    DTXException
  - emitSaxEvents
```
protected void emitSaxEvents(java.sql.ResultSet rs)
                      throws DTXException
```
    Throws:
    
    DTXException
  - emitSaxInt
```
protected boolean emitSaxInt(java.sql.ResultSet rs,
                             int idIndex)
                      throws DTXException
```
    Throws:
    
    DTXException
  - parseOQL
```
protected java.lang.String parseOQL(java.lang.String oql)
                             throws DTXException
```
    Throws:
    
    DTXException
  - initQuery
```
protected void initQuery(ClassMapping clsMapping,
                         QueryExpression expr)
                  throws DTXException
```
    Throws:
    
    DTXException

Class DTXQuery

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

_eng

_handler

_logWriter

_stmt

_objName

_objType

_clsMapping

_ids

_lastCol

_cols

_classes

Constructor Detail

DTXQuery

Method Detail

setHandler

setLogWriter

bind

bind

bind

bind

bind

bind

bind

execute

setEngine

prepare

emitSaxEvents

emitSaxInt

parseOQL

initQuery