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/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2003-2009, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
// $Id$
package scala.dbc.statement
/** A join behaviour in a <code>Jointure</code>. */
abstract class JoinType {
/** A SQL-99 string representation of the join behaviour. */
def sqlString: String
}
object JoinType {
/** A join behaviour where a joined tuple is created only when a
* corresponding tuple exists in both original relations.
*/
case object Inner extends JoinType {
val sqlString = "INNER JOIN"
}
/** A join behaviour family where a joined tuple is created even when a
* tuple has no corresponding tuple in the other relation. The fields
* populated by values of the other tuple will receive the NULL value.
*/
abstract class Outer extends JoinType
object Outer {
/** An outer join behaviour where there will be at least on tuple for
* every tuple in the left relation.
*/
case object Left extends Outer {
val sqlString = "LEFT OUTER JOIN"
}
/** An outer join behaviour where there will be at least on tuple for
* every tuple in the right relation.
*/
case object Right extends Outer {
val sqlString = "RIGHT OUTER JOIN"
}
/** An outer join behaviour where there will be at least on tuple for
* every tuple in both right and left relations.
*/
case object Full extends Outer {
val sqlString = "FULL OUTER JOIN"
}
}
}
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