Class CountExpression

java.lang.Object
net.sf.basedb.core.query.CountExpression
All Implemented Interfaces:
Expression, QueryElement

public class CountExpression
extends Object
implements Expression
Count the number of values: COUNT(e)
Version:
2.0
Author:
Nicklas
See Also:
Aggregations.count(Expression, boolean)
Last modified
$Date: 2012-09-14 09:28:35 +0200 (fr, 14 sep 2012) $
  • Field Details

    • e

      private final Expression e
    • distinct

      private final boolean distinct
  • Constructor Details

    • CountExpression

      CountExpression​(Expression e, boolean distinct)
  • Method Details

    • 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 executed
      dc - 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 to count
    • toString

      public String toString()
      Overrides:
      toString in class Object
    • equals

      public boolean equals​(Object other)
      This expression is equal to another CountExpression if their child expressions are equal and have the same DISTINCT setting.
      Overrides:
      equals in class Object
    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object