java.lang.Object
- org.intermine.objectstore.query.QueryExpression

All Implemented Interfaces:

QueryEvaluable, QueryNode, QueryOrderable, QuerySelectable
```
public class QueryExpression
extends java.lang.Object
implements QueryEvaluable
```
Represents an arithmetic or substring expression, analogous to those in SQL

Author:

Mark Woodbridge, Richard Smith, Matthew Wakeling

Field Summary

Fields
Modifier and Type	Field	Description
`static int`	`ADD`	Addition of two numeric fields
`static int`	`DIVIDE`	Division of two numeric fields
`static int`	`GREATEST`	Return the greatest value from two expressions, e.g.
`static int`	`INDEX_OF`	Position of specified string in other specified string
`static int`	`LEAST`	Return the lowest value from two expressions, e.g.
`static int`	`LOWER`	Lower case version of the given string
`static int`	`MODULO`	Return the modulo of two expressions, e.g.
`static int`	`MULTIPLY`	Multiplication of two numeric fields
`static int`	`SUBSTRING`	Substring of specified length from index in string
`static int`	`SUBTRACT`	Subtraction of two numeric fields
`static int`	`UPPER`	Upper case version of the given string

Constructor Summary

Constructors
Constructor	Description
`QueryExpression(int op, QueryEvaluable arg)`	Constructs a String QueryExpression to perform upper and lowercase conversions.
`QueryExpression(QueryEvaluable arg1, int op, QueryEvaluable arg2)`	Constructs an arithmetic QueryExpression from two evaluable items
`QueryExpression(QueryEvaluable arg, QueryEvaluable pos, QueryEvaluable len)`	Constructs a substring QueryExpression from a QueryEvaluable and start and length QueryEvaluables

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`int`	`getApproximateType()`	Returns an integer representing the approximate type of this QueryEvaluable, in the case where an accurate type cannot be ascertained.
`QueryEvaluable`	`getArg1()`	Returns the left argument of the expression.
`QueryEvaluable`	`getArg2()`	Returns the right argument, or the position argument of the substring.
`QueryEvaluable`	`getArg3()`	Returns the length argument of a substring expression.
`int`	`getOperation()`	Returns the operation.
`java.lang.Class<?>`	`getType()`	Get Java type represented by this item.
`void`	`youAreType(java.lang.Class<?> cls)`	Allows a caller to suggest to this object that it holds a value of a certain type.

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

- Field Detail
  - ADD
```
public static final int ADD
```
    Addition of two numeric fields
    
    See Also:
    
    Constant Field Values
  - SUBTRACT
```
public static final int SUBTRACT
```
    Subtraction of two numeric fields
    
    See Also:
    
    Constant Field Values
  - MULTIPLY
```
public static final int MULTIPLY
```
    Multiplication of two numeric fields
    
    See Also:
    
    Constant Field Values
  - DIVIDE
```
public static final int DIVIDE
```
    Division of two numeric fields
    
    See Also:
    
    Constant Field Values
  - SUBSTRING
```
public static final int SUBSTRING
```
    Substring of specified length from index in string
    
    See Also:
    
    Constant Field Values
  - INDEX_OF
```
public static final int INDEX_OF
```
    Position of specified string in other specified string
    
    See Also:
    
    Constant Field Values
  - LOWER
```
public static final int LOWER
```
    Lower case version of the given string
    
    See Also:
    
    Constant Field Values
  - UPPER
```
public static final int UPPER
```
    Upper case version of the given string
    
    See Also:
    
    Constant Field Values
  - GREATEST
```
public static final int GREATEST
```
    Return the greatest value from two expressions, e.g. (col1, 0)
    
    See Also:
    
    Constant Field Values
  - LEAST
```
public static final int LEAST
```
    Return the lowest value from two expressions, e.g. (col1, 0)
    
    See Also:
    
    Constant Field Values
  - MODULO
```
public static final int MODULO
```
    Return the modulo of two expressions, e.g. (col1, 2)
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - QueryExpression
```
public QueryExpression(QueryEvaluable arg1,
                       int op,
                       QueryEvaluable arg2)
```
    Constructs an arithmetic QueryExpression from two evaluable items
    
    Parameters:
    
    arg1 - the first argument
    
    op - the required operation
    
    arg2 - the second argument
    
    Throws:
    
    java.lang.IllegalArgumentException - if there is a mismatch between any of the argument types and the specified operation
  - QueryExpression
```
public QueryExpression(QueryEvaluable arg,
                       QueryEvaluable pos,
                       QueryEvaluable len)
```
    Constructs a substring QueryExpression from a QueryEvaluable and start and length QueryEvaluables
    
    Parameters:
    
    arg - A QueryEvaluable representing a String
    
    pos - start index
    
    len - length in characters
    
    Throws:
    
    java.lang.IllegalArgumentException - if there is a mismatch between the argument type and the specified operation
  - QueryExpression
```
public QueryExpression(int op,
                       QueryEvaluable arg)
```
    Constructs a String QueryExpression to perform upper and lowercase conversions.
    
    Parameters:
    
    op - the required operation
    
    arg - the String argument
    
    Throws:
    
    java.lang.IllegalArgumentException - if there is a mismatch between the argument and operation
- Method Detail
  - getType
```
public java.lang.Class<?> getType()
```
    Get Java type represented by this item.
    
    Specified by:
    
    getType in interface QueryOrderable
    
    Specified by:
    
    getType in interface QuerySelectable
    
    Returns:
    
    class describing the type
  - getOperation
```
public int getOperation()
```
    Returns the operation.
    
    Returns:
    
    the operation of the expression
  - getArg1
```
public QueryEvaluable getArg1()
```
    Returns the left argument of the expression.
    
    Returns:
    
    the left argument
  - getArg2
```
public QueryEvaluable getArg2()
```
    Returns the right argument, or the position argument of the substring.
    
    Returns:
    
    argument 2
  - getArg3
```
public QueryEvaluable getArg3()
```
    Returns the length argument of a substring expression.
    
    Returns:
    
    argument 3
  - youAreType
```
public void youAreType(java.lang.Class<?> cls)
```
    Allows a caller to suggest to this object that it holds a value of a certain type. This method should only be called on objects which report their type to be UnknownTypeValue. Otherwise, this method will throw and exception.
    
    Specified by:
    
    youAreType in interface QueryEvaluable
    
    Parameters:
    
    cls - the Class of the type to be imposed on this object
  - getApproximateType
```
public int getApproximateType()
```
    Returns an integer representing the approximate type of this QueryEvaluable, in the case where an accurate type cannot be ascertained.
    
    Specified by:
    
    getApproximateType in interface QueryEvaluable
    
    Returns:
    
    an int, as described in UnknownTypeValue

Class QueryExpression

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

ADD

SUBTRACT

MULTIPLY

DIVIDE

SUBSTRING

INDEX_OF

LOWER

UPPER

GREATEST

LEAST

MODULO

Constructor Detail

QueryExpression

QueryExpression

QueryExpression

Method Detail

getType

getOperation

getArg1

getArg2

getArg3

youAreType

getApproximateType