ParseTreeWalker (Castor JavaDoc)

java.lang.Object
- org.exolab.castor.jdo.oql.ParseTreeWalker

```
public class ParseTreeWalker
extends java.lang.Object
```
A class which walks the parse tree created by the parser to check for errors and translate to SQL.

Version:

$Revision: 8459 $ $Date: 2006-04-25 15:08:23 -0600 (Tue, 25 Apr 2006) $

Author:

Nissim Karpenstein

Field Summary

Fields
Modifier and Type	Field	Description
`static int`	`AGGREGATE`
`static int`	`DEPENDANT_OBJECT`
`static int`	`DEPENDANT_OBJECT_VALUE`
`static int`	`DEPENDANT_VALUE`
`static int`	`FUNCTION`
`static int`	`MAX_TABLE_LENGTH`
`static int`	`PARENT_OBJECT`

Constructor Summary

Constructors
Constructor	Description
`ParseTreeWalker(LockEngine dbEngine, ParseTreeNode parseTree, java.lang.ClassLoader classLoader, DbMetaInfo dbInfo)`	Creates a new parse tree walker.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`java.lang.String`	`buildTableAlias(java.lang.String tableName, java.util.Vector<java.lang.String> path, int tableIndex)`	Builds the alias name for a table from the path info.
`ClassDescriptor`	`getClassDescriptor()`	Accessor method for _clsDesc.
`java.lang.Class<?>`	`getObjClass()`	Accessor method for _objClass.
`java.util.Hashtable<java.lang.Integer,ParamInfo>`	`getParamInfo()`	Accessor method for _paramInfo.
`java.util.Vector<java.lang.String>`	`getProjectionInfo()`	Method to get path info for the selected object.
`int`	`getProjectionType()`	Accessor method for _projectionType.
`QueryExpression`	`getQueryExpression()`	Accessor method for private _queryExpr member.

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

- Field Detail
  - AGGREGATE
```
public static final int AGGREGATE
```
    See Also:
    
    Constant Field Values
  - FUNCTION
```
public static final int FUNCTION
```
    See Also:
    
    Constant Field Values
  - PARENT_OBJECT
```
public static final int PARENT_OBJECT
```
    See Also:
    
    Constant Field Values
  - DEPENDANT_OBJECT
```
public static final int DEPENDANT_OBJECT
```
    See Also:
    
    Constant Field Values
  - DEPENDANT_OBJECT_VALUE
```
public static final int DEPENDANT_OBJECT_VALUE
```
    See Also:
    
    Constant Field Values
  - DEPENDANT_VALUE
```
public static final int DEPENDANT_VALUE
```
    See Also:
    
    Constant Field Values
  - MAX_TABLE_LENGTH
```
public static final int MAX_TABLE_LENGTH
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - ParseTreeWalker
```
public ParseTreeWalker(LockEngine dbEngine,
                       ParseTreeNode parseTree,
                       java.lang.ClassLoader classLoader,
                       DbMetaInfo dbInfo)
                throws QueryException
```
    Creates a new parse tree walker. Which checks the tree for errors, and generates a QueryExpression containing the SQL translation.
    
    Parameters:
    
    dbEngine - The Persistence Engine
    
    parseTree - The parse tree to walk
    
    classLoader - A ClassLoader instance to load classes.
    
    Throws:
    
    QueryException - Thrown by checkErrors.
- Method Detail
  - getObjClass
```
public java.lang.Class<?> getObjClass()
```
    Accessor method for _objClass.
    
    Returns:
    
    The _objClass member.
  - getProjectionType
```
public int getProjectionType()
```
    Accessor method for _projectionType.
    
    Returns:
    
    The _projectionType member.
  - getQueryExpression
```
public QueryExpression getQueryExpression()
```
    Accessor method for private _queryExpr member.
    
    Returns:
    
    private _queryExpr member
  - getParamInfo
```
public java.util.Hashtable<java.lang.Integer,ParamInfo> getParamInfo()
```
    Accessor method for _paramInfo.
    
    Returns:
    
    The _paramInfo member.
  - getClassDescriptor
```
public ClassDescriptor getClassDescriptor()
```
    Accessor method for _clsDesc.
    
    Returns:
    
    The _clsDesc member.
  - getProjectionInfo
```
public java.util.Vector<java.lang.String> getProjectionInfo()
```
    Method to get path info for the selected object. This is the path which will be used by the QueryResults to follow the path if the object selected is a DEPENDANT_OBJECT or DEPENDANT_OBJECT_VALUE. Any other projectionTypes do not need this, so null will be returned.
    
    Returns:
    
    Path info for the selected element, null otherwise.
  - buildTableAlias
```
public java.lang.String buildTableAlias(java.lang.String tableName,
                                        java.util.Vector<java.lang.String> path,
                                        int tableIndex)
```
    Builds the alias name for a table from the path info.
    
    Parameters:
    
    tableName - The name of the table to add to the select clause
    
    path - The path info vector to build the alias with
    
    tableIndex - Field index in the path info
    
    Returns:
    
    Alias name for a given table.

Class ParseTreeWalker

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

AGGREGATE

FUNCTION

PARENT_OBJECT

DEPENDANT_OBJECT

DEPENDANT_OBJECT_VALUE

DEPENDANT_VALUE

MAX_TABLE_LENGTH

Constructor Detail

ParseTreeWalker

Method Detail

getObjClass

getProjectionType

getQueryExpression

getParamInfo

getClassDescriptor

getProjectionInfo

buildTableAlias