net.sf.basedb.core.query
Class LogExpression
java.lang.Object
net.sf.basedb.core.query.LogExpression
- All Implemented Interfaces:
- Expression, QueryElement
public class LogExpression
- extends Object
- implements Expression
Take the n-based logarithm of an expression: log(n, e).
The n-based logarithm is easily calculated as the natural logarithm of x
divided natural logarithm of the base, ie. log(n, e) = ln(e) / ln(n)
- Version:
- 2.0
- Author:
- Nicklas
- See Also:
Expressions.log(double, Expression)
- Last modified
- $Date: 2010-04-21 11:48:29 +0200 (Wed, 21 Apr 2010) $
base
private final double base
e1
private final Expression e1
LogExpression
LogExpression(double base,
Expression e1)
toQl
public String toQl(Query query,
DbControl dc)
throws BaseException
- Description copied from interface:
QueryElement
- Create a query language string of the query element. Use the
Query.getQueryType()
method to find out which query language is wanted
in case the element requires different syntax for different languages.
- Specified by:
toQl
in interface QueryElement
- Parameters:
query
- The query that is about to be executeddc
- The DbControl
object used to execute the query
- Throws:
BaseException
- If there is any other error
getChildren
public Collection<? extends QueryElement> getChildren()
- Description copied from interface:
QueryElement
- Get the children of this query element or null if it has no children.
For example the
AddExpression
has two children, the expression
beeing added.
- Specified by:
getChildren
in interface QueryElement
- Returns:
- The expression
toString
public String toString()
- Overrides:
toString
in class Object
equals
public boolean equals(Object other)
- This expression is equal to another LogExpression if their
child expressions and bases are equal.
- Overrides:
equals
in class Object
hashCode
public int hashCode()
- Overrides:
hashCode
in class Object