org.proteios.core.query
Class Expressions

java.lang.Object
  org.proteios.core.query.Expressions

public class Expressions
extends Object

A factory class to create expressions.

Version:

2.0

Author:

Samuel, Nicklas

Last modified

$Date: 2009-04-09 08:48:11 +0200 (Thu, 09 Apr 2009) $

Field Summary

static Pattern

PARAMETER_REGEXP A parameter name can only contain the characters a-z, A-Z or 0-9.

Constructor Summary

Expressions()

Method Summary

static Expression	add(Expression e1, Expression e2) Add two expressions: new expression = e1 + e2.
static Expression	aFloat(float value) Create a constant expression from a float.
static Expression	divide(Expression e1, Expression e2) Divide one expression by another: new expression = e1 / e2.
static Expression	integer(int value) Create a constant expression from an integer.
static Expression	ln(Expression e) Take the natural logarithm of an expression: new expression = ln(e).
static Expression	log(double n, Expression e) Take the n-based logarithm of an expression: new expression = log(n, e).
static Expression	log10(Expression e) Take the 10-based logarithm of an expression: new expression = log10(e).
static Expression	log2(Expression e) Take the 2-based logarithm of an expression: new expression = log2(e).
static Expression	multiply(Expression e1, Expression e2) Multiply two expressions: new expression = e1 * e2.
static Expression	negate(Expression e) Negate an expression: new expression = -e1.
static Expression	parameter(String name) Create an expresson for a parameter without a default value or type.
static Expression	parameter(String name, Object value) Create an expresson for a parameter with a default value but no type.
static Expression	parameter(String name, Object value, Type valueType) Create an expresson for a parameter with a default value and type.
static Expression	parameter(String name, Type valueType) Create an expresson for a typed parameter without a default value.
static Expression	selected(Select select) Create an expression for an already selected query element.
static Expression	sqrt(Expression e) Take the square root of an expression: new expression = sqrt(e).
static Expression	string(String value) Create a constant expression from a string.
static Expression	subtract(Expression e1, Expression e2) Subtract one expression from another: new expression = e1 - e2.

Methods inherited from class java.lang.Object

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

Field Detail

PARAMETER_REGEXP

public static final Pattern PARAMETER_REGEXP

A parameter name can only contain the characters a-z, A-Z or 0-9.

Constructor Detail

Expressions

public Expressions()

Method Detail

add

public static Expression add(Expression e1,
                             Expression e2)
                      throws InvalidDataException

Add two expressions: new expression = e1 + e2.

Parameters:

e1 - The left value

e2 - The right value

Returns:

The new expression

Throws:

InvalidDataException - If any of the arguments are null

subtract

public static Expression subtract(Expression e1,
                                  Expression e2)
                           throws InvalidDataException

Subtract one expression from another: new expression = e1 - e2.

Parameters:

e1 - The left value

e2 - The right value

Returns:

The new expression

Throws:

InvalidDataException - If any of the arguments are null

divide

public static Expression divide(Expression e1,
                                Expression e2)
                         throws InvalidDataException

Divide one expression by another: new expression = e1 / e2.

Parameters:

e1 - The numerator

e2 - The denominator

Returns:

The new expression

Throws:

InvalidDataException - If any of the arguments are null

multiply

public static Expression multiply(Expression e1,
                                  Expression e2)
                           throws InvalidDataException

Multiply two expressions: new expression = e1 * e2.

Parameters:

e1 - The left value

e2 - The right value

Returns:

The new expression

Throws:

InvalidDataException - If any of the arguments are null

negate

public static Expression negate(Expression e)
                         throws InvalidDataException

Negate an expression: new expression = -e1.

Parameters:

e - The expression to negate

Returns:

The new expression

Throws:

InvalidDataException - If the argument is null

integer

public static Expression integer(int value)

Create a constant expression from an integer.

Parameters:

value - The value to create an expression for

Returns:

The expression

aFloat

public static Expression aFloat(float value)

Create a constant expression from a float.

Parameters:

value - The value to create an expression for

Returns:

The expression

string

public static Expression string(String value)
                         throws InvalidDataException

Create a constant expression from a string. Internally this is implemented as parameter with a default value. Ie. parameter(String, Object). In most cases it is better to use that method instead of this.

Parameters:

value - The string value

Returns:

The expression

Throws:

InvalidDataException - If the value is null

parameter

public static Expression parameter(String name)
                            throws InvalidDataException

Create an expresson for a parameter without a default value or type.

Throws:

InvalidDataException

See Also:

parameter(String, Object, Type), Query.setParameter(String, Object, Type)

parameter

public static Expression parameter(String name,
                                   Type valueType)
                            throws InvalidDataException

Create an expresson for a typed parameter without a default value.

Throws:

InvalidDataException

See Also:

parameter(String, Object, Type), Query.setParameter(String, Object, Type)

parameter

public static Expression parameter(String name,
                                   Object value)
                            throws InvalidDataException

Create an expresson for a parameter with a default value but no type.

Throws:

InvalidDataException

See Also:

parameter(String, Object, Type)

parameter

public static Expression parameter(String name,
                                   Object value,
                                   Type valueType)
                            throws InvalidDataException

Create an expresson for a parameter with a default value and type.

Parameters:

name - The name of the parameter

value - The default value of the parameter, or null if no default is needed

valueType - The type of the parameter, or null if not used

Returns:

An expression representing the parameter

Throws:

InvalidUseOfNullException - If the argument is null or contains invalid characters

InvalidDataException

See Also:

Query.setParameter(String, Object, Type), PARAMETER_REGEXP

selected

public static Expression selected(Select select)
                           throws InvalidDataException

Create an expression for an already selected query element. If an alias has been specified it will be used, otherwise the entire expression is built again.

Parameters:

select - A selected query element

Returns:

A expression object representing the selected expression

Throws:

InvalidUseOfNullException - If the argument is null

InvalidDataException

log10

public static Expression log10(Expression e)
                        throws InvalidDataException

Take the 10-based logarithm of an expression: new expression = log10(e).

Parameters:

e - The expression to take the logarithm of

Returns:

The new expression

Throws:

InvalidDataException - If the argument is null

log2

public static Expression log2(Expression e)
                       throws InvalidDataException

Take the 2-based logarithm of an expression: new expression = log2(e).

Parameters:

e - The expression to take the logarithm of

Returns:

The new expression

Throws:

InvalidDataException - If the argument is null

ln

public static Expression ln(Expression e)
                     throws InvalidDataException

Take the natural logarithm of an expression: new expression = ln(e).

Parameters:

e - The expression to take the logarithm of

Returns:

The new expression

Throws:

InvalidDataException - If the argument is null

log

public static Expression log(double n,
                             Expression e)
                      throws InvalidDataException

Take the n-based logarithm of an expression: new expression = log(n, e).

Parameters:

n - The log base, must be > 0

e - The expression to take the logarithm of

Returns:

The new expression

Throws:

InvalidDataException - If the expression is null or if the base is 0 or below

sqrt

public static Expression sqrt(Expression e)
                       throws InvalidDataException

Take the square root of an expression: new expression = sqrt(e).

Parameters:

e - The expression to take the square root of

Returns:

The new expression

Throws:

InvalidDataException - If the argument is null