org.apache.openjpa.jdbc.kernel.exps
Class GetColumn
java.lang.Object
   org.apache.openjpa.jdbc.kernel.exps.GetColumn
org.apache.openjpa.jdbc.kernel.exps.GetColumn
- All Implemented Interfaces: 
- java.io.Serializable, JDBCFilterListener, FilterListener
- public class GetColumn 
- extends java.lang.Object- implements JDBCFilterListener
Returns the SQL alias of the named column for use in a query. Note that
 to retrieve columns in the table of the candidate object, you must
 explicitly qualify the extension with this, as demonstrated
 in the second example below.
  Examples:
  "company.address.ext:getColumn (\"ID\") == 5"
 "this.ext:getColumn (\"CLS\") == \"org.apache.openjpa.example.Person\""
 
- See Also:
- Serialized Form
| Field Summary | 
| static java.lang.String | TAG
 | 
 
 
| Method Summary | 
|  void | appendTo(SQLBuffer buf,
         FilterValue target,
         FilterValue[] args,
         ClassMapping type,
         JDBCStore store)Append the SQL for this expression or value.
 | 
|  java.lang.Object | evaluate(java.lang.Object target,
         java.lang.Class targetClass,
         java.lang.Object[] args,
         java.lang.Class[] argClasses,
         java.lang.Object candidate,
         StoreContext ctx)
 | 
|  boolean | expectsArguments()
 | 
|  boolean | expectsTarget()
 | 
|  java.lang.String | getTag()
 | 
|  java.lang.Class | getType(java.lang.Class targetClass,
        java.lang.Class[] argClasses)
 | 
 
| Methods inherited from class java.lang.Object | 
| clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait | 
 
TAG
public static final java.lang.String TAG
- See Also:
- Constant Field Values
GetColumn
public GetColumn()
getTag
public java.lang.String getTag()
- 
- Specified by:
- getTagin interface- FilterListener
 
- 
 
expectsArguments
public boolean expectsArguments()
- 
- Specified by:
- expectsArgumentsin interface- FilterListener
 
- 
 
expectsTarget
public boolean expectsTarget()
- 
- Specified by:
- expectsTargetin interface- FilterListener
 
- 
 
evaluate
public java.lang.Object evaluate(java.lang.Object target,
                                 java.lang.Class targetClass,
                                 java.lang.Object[] args,
                                 java.lang.Class[] argClasses,
                                 java.lang.Object candidate,
                                 StoreContext ctx)
- 
- Specified by:
- evaluatein interface- FilterListener
 
- 
 
appendTo
public void appendTo(SQLBuffer buf,
                     FilterValue target,
                     FilterValue[] args,
                     ClassMapping type,
                     JDBCStore store)
- Description copied from interface: JDBCFilterListener
- Append the SQL for this expression or value.
 
- 
- Specified by:
- appendToin interface- JDBCFilterListener
 
- 
- Parameters:
- buf- the SQL buffer to append to
- target- the target to act on, or null if the listener
 doesn't expect a target
- args- the values of the arguments given in the filter, or
 null if this listener doesn't expect arguments
- type- the class mapping for the query's candidate class
- store- the store that owns the query
 
getType
public java.lang.Class getType(java.lang.Class targetClass,
                               java.lang.Class[] argClasses)
- 
- Specified by:
- getTypein interface- FilterListener
 
- 
 
Copyright © 2006-2008 Apache Software Foundation. All Rights Reserved.