ModSQL
Class Operator_Concat

java.lang.Object
  |
  +--ModSQL.AbstractFunction
        |
        +--ModSQL.Operator
              |
              +--ModSQL.Operator_Concat

All Implemented Interfaces:

Function

final class Operator_Concat

extends Operator

SQL operator "||".

Author:

chris.studholme@utoronto.ca

Fields inherited from class ModSQL.AbstractFunction

all_constant, constant_non_null, evaluate_order, evaluate_order_array, out_of_order, parameter_constant, parameter_value, parameters, parameters_array

Fields inherited from interface ModSQL.Function

MATCH_BEGINS, MATCH_EQU, MATCH_GT, MATCH_GTE, MATCH_LT, MATCH_LTE, MATCH_NE

Constructor Summary

(package private)

Operator_Concat()

Method Summary

Object	evaluate(boolean aggregate) Evaluate parameters and compute the function.
Object	evaluate(int match_op, Object match_value) Evaluate parameters and compute the function.
String	functionName() Returns "#CONCAT".
int	getMaxResultSize() Return the maximum number of characters that this function expects to return in a String object.
int	getSQLType() Return the SQL type of the value that this function expects to return.
void	optimize() Prepare the function for use.

Methods inherited from class ModSQL.Operator

addAllParameters, addAllParametersNegate, addAllParametersNot, removeDoubleNegation, removeDoubleNot

Methods inherited from class ModSQL.AbstractFunction

addParameter, convertToSQLType, evaluateConstantParameters, evaluateOrder, evaluateParameters, evaluateParameters, getCompatableType, getObjectSQLType, getParameter, getParameterCount, isAggregate, isConstant, postfixParameters, prefixParameters, registerWith, reset, toString

Methods inherited from class java.lang.Object

, clone, equals, finalize, getClass, hashCode, notify, notifyAll, registerNatives, wait, wait, wait

Constructor Detail

Operator_Concat

Operator_Concat()

Method Detail

optimize

public void optimize()
              throws SQLException

Prepare the function for use. This method verifies that the parameters are strings.

Overrides:

optimize in class AbstractFunction

Throws:

SQLException - if the parameters are invalid

functionName

public String functionName()

Returns "#CONCAT".

Overrides:

functionName in class AbstractFunction

Returns:

name of function

getSQLType

public int getSQLType()
               throws SQLException

Return the SQL type of the value that this function expects to return. The data returned by the function must either be of this type, or null.

Returns:

SQL type of data to be returned

Throws:

SQLException - if a database-access error occurs.

getMaxResultSize

public int getMaxResultSize()
                     throws SQLException

Return the maximum number of characters that this function expects to return in a String object. If the maximum size is unknown for any of the parameter, this method returns -1.

Returns:

maximum size of String returned or -1 if unknown

Throws:

SQLException - if a database-access error occurs

evaluate

public Object evaluate(boolean aggregate)
                throws SQLException,
                       EndOfTable

Evaluate parameters and compute the function.

Parameters:

aggregate - passed to parameters

Returns:

result object

Throws:

SQLException - if a database-access error occurs

EndOfTable - if thrown by a parameter

evaluate

public Object evaluate(int match_op,
                       Object match_value)
                throws SQLException,
                       EndOfTable

Evaluate parameters and compute the function.

Overrides:

evaluate in class AbstractFunction

Parameters:

match_op - how the value should be matched

match_value - desired value

Returns:

result object

Throws:

SQLException - if a database-access error occurs

EndOfTable - if thrown by a parameter