org.apache.empire.db.expr.column
Class DBConcatExpr

java.lang.Object
  extended by org.apache.empire.commons.ErrorObject
      extended by org.apache.empire.db.DBObject
          extended by org.apache.empire.db.DBExpr
              extended by org.apache.empire.db.DBColumnExpr
                  extended by org.apache.empire.db.expr.column.DBConcatExpr
All Implemented Interfaces:
ErrorInfo, ColumnExpr

public class DBConcatExpr
extends DBColumnExpr

This class is used for performing string concatenation in SQL

There is no need to explicitly create instances of this class.
Instead use DBColumnExpr.append(Object)


Field Summary
 
Fields inherited from class org.apache.empire.db.DBColumnExpr
DBCOLATTR_TITLE, DBCOLATTR_TYPE
 
Fields inherited from class org.apache.empire.db.DBExpr
CTX_ALIAS, CTX_ALL, CTX_DEFAULT, CTX_FULLNAME, CTX_NAME, CTX_NOPARENTHESES, CTX_VALUE
 
Constructor Summary
DBConcatExpr(DBColumnExpr left, java.lang.Object right)
          Constructs a new DBConcatExpr object set the specified parameters to this object.
 
Method Summary
 void addReferencedColumns(java.util.Set<DBColumn> list)
          Internal function to obtain all DBColumnExpr-objects used by this expression.
 void addSQL(java.lang.StringBuilder buf, long context)
          Creates the SQL-Command concatenate a specified column with a specified value sets the column with a specified value to the SQL-Command.
 org.w3c.dom.Element addXml(org.w3c.dom.Element parent, long flags)
          This helper function calls the DBColumnExpr.addXML(Element, long) method.
 DBDatabase getDatabase()
          Returns the current DBDatabase object.
 DataType getDataType()
          Returns the data type: DT_TEXT.
 java.lang.String getName()
          This helper function returns expression name.
 DBColumn getUpdateColumn()
          returns null
 boolean isAggregate()
          Always returns false since a concat expression cannot be an aggregate.
 
Methods inherited from class org.apache.empire.db.DBColumnExpr
abs, append, as, as, avg, cmp, coalesce, convertTo, convertTo, count, countDistinct, day, decode, decode, decode, decode, decode, decode, divideBy, getAttribute, getBeanPropertyName, getControlType, getOptions, getSourceColumn, getTitle, in, indexOf, indexOf, indexOf, is, isBetween, isGreaterThan, isLessOrEqual, isMoreOrEqual, isNot, isNotBetween, isSmallerThan, length, like, like, likeLower, likeUpper, lower, max, min, minus, minus, month, multiplyWith, notIn, notLike, nvl, parenthesis, plus, plus, replace, reverse, round, setAttribute, setBeanPropertyName, setControlType, setOptions, setTitle, substring, substring, substring, substring, substring, substring, sum, toChar, toChar, trim, trimLeft, trimRight, trunc, upper, when, year
 
Methods inherited from class org.apache.empire.db.DBExpr
getValueClass
 
Methods inherited from class org.apache.empire.commons.ErrorObject
clearError, getErrorMessage, getErrorParams, getErrorSource, getErrorType, getMessage, hasError, isExceptionsEnabled, setExceptionsEnabled
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

DBConcatExpr

public DBConcatExpr(DBColumnExpr left,
                    java.lang.Object right)
Constructs a new DBConcatExpr object set the specified parameters to this object.

Method Detail

getDatabase

public DBDatabase getDatabase()
Returns the current DBDatabase object.

Specified by:
getDatabase in class DBObject
Returns:
the current DBDatabase object

getDataType

public DataType getDataType()
Returns the data type: DT_TEXT.

Specified by:
getDataType in interface ColumnExpr
Specified by:
getDataType in class DBColumnExpr
Returns:
the data type: DT_TEXT
See Also:
DataType

getName

public java.lang.String getName()
This helper function returns expression name.

Specified by:
getName in interface ColumnExpr
Specified by:
getName in class DBColumnExpr
Returns:
the expression name

addXml

public org.w3c.dom.Element addXml(org.w3c.dom.Element parent,
                                  long flags)
This helper function calls the DBColumnExpr.addXML(Element, long) method.

Specified by:
addXml in class DBColumnExpr
Parameters:
parent - the parent element to which to append the column description
flags - currenly not used
Returns:
the newly created child element

getUpdateColumn

public DBColumn getUpdateColumn()
returns null

Specified by:
getUpdateColumn in class DBColumnExpr
Returns:
null

isAggregate

public boolean isAggregate()
Always returns false since a concat expression cannot be an aggregate.

Specified by:
isAggregate in class DBColumnExpr
Returns:
false

addReferencedColumns

public void addReferencedColumns(java.util.Set<DBColumn> list)
Description copied from class: DBExpr
Internal function to obtain all DBColumnExpr-objects used by this expression.

Specified by:
addReferencedColumns in class DBExpr
Parameters:
list - list to which all used column expressions must be added
See Also:
DBExpr.addReferencedColumns(Set)

addSQL

public void addSQL(java.lang.StringBuilder buf,
                   long context)
Creates the SQL-Command concatenate a specified column with a specified value sets the column with a specified value to the SQL-Command.

Specified by:
addSQL in class DBExpr
Parameters:
buf - the SQL statment
context - the current SQL-Command context