: Class Operator_Multiply

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## ModSQL
Class Operator_Multiply

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

All Implemented Interfaces:
  Function

final class Operator_Multiply
extends Operator

SQL operator "*".

Author:
  chris.studholme@utoronto.ca

Field Summary
`private Number` | `constant_value` Product of constant parameters.
`private int` | `return_type` Return type of operator.

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_Multiply()`

Method Summary
`void` | `addParameter(Function function)` Adds a function to the list of parameters maintained by this operator.
`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 "#MULT".
`int` | `getMaxResultSize()` Returns -1 as this operator will never return 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
`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`

Field Detail

### constant_value

    private Number constant_value

  Product of constant parameters.

### return_type

    private int return_type

  Return type of operator.

Constructor Detail

### Operator_Multiply

    Operator_Multiply()

Method Detail

### addParameter

    public void addParameter(Function function)
                      throws SQLException

  Adds a function to the list of parameters maintained by this operator. If the function is of type Operator_Negate and has double negation, the double negation will be removed. If the function is of type Operator_Multiply, or Operator_Negate followed by Operator_Multiply, the functions parameters (factors) are added instead of the function.
  Overrides:
    `addParameter` in class `AbstractFunction`
  Parameters:
    `function` - function to add
  Throws:
    `SQLException` - if a database error occurs

### optimize

    public void optimize()
                  throws SQLException

  Prepare the function for use. This method checks the parameters, figures out an appropriate return type, and computes the product of all constant parameters.

  Overrides:
    `optimize` in class `AbstractFunction`
  Throws:
    `SQLException` - if the parameters are invalid

### functionName

    public String functionName()

  Returns "#MULT".
  Overrides:
    `functionName` in class `AbstractFunction`
  Returns:
    name of function

### getSQLType

    public int getSQLType()

  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

### getMaxResultSize

    public int getMaxResultSize()

  Returns -1 as this operator will never return a String object.
  Returns:
    maximum size of String returned or -1 if unknown

### 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

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