discriminatorcolumn.html
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><!--NewPage--><HTML><HEAD><!-- Generated by javadoc (build 1.5.0_14) on Mon Jan 28 05:47:04 PST 2008 --><TITLE>DiscriminatorColumn (Java EE 5)</TITLE><META NAME="keywords" CONTENT="javax.persistence.DiscriminatorColumn class"><LINK REL ="stylesheet" TYPE="text/css" HREF="../../stylesheet.css" TITLE="Style"><SCRIPT type="text/javascript">function windowTitle(){ parent.document.title="DiscriminatorColumn (Java EE 5)";}</SCRIPT><NOSCRIPT></NOSCRIPT></HEAD><BODY BGCOLOR="white" onload="windowTitle();"><!-- ========= START OF TOP NAVBAR ======= --><A NAME="navbar_top"><!-- --></A><A HREF="#skip-navbar_top" title="Skip navigation links"></A><TABLE BORDER="0" WIDTH="100%" CELLPADDING="1" CELLSPACING="0" SUMMARY=""><TR><TD COLSPAN=2 BGCOLOR="#EEEEFF" CLASS="NavBarCell1"><A NAME="navbar_top_firstrow"><!-- --></A><TABLE BORDER="0" CELLPADDING="0" CELLSPACING="3" SUMMARY=""> <TR ALIGN="center" 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BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2"> <A HREF="../../javax/persistence/ColumnResult.html" title="annotation in javax.persistence"><B>PREV CLASS</B></A> <A HREF="../../javax/persistence/DiscriminatorType.html" title="enum in javax.persistence"><B>NEXT CLASS</B></A></FONT></TD><TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2"> <A HREF="../../index.html?javax/persistence/DiscriminatorColumn.html" target="_top"><B>FRAMES</B></A> <A HREF="DiscriminatorColumn.html" target="_top"><B>NO FRAMES</B></A> <SCRIPT type="text/javascript"> <!-- if(window==top) { document.writeln('<A HREF="../../allclasses-noframe.html"><B>All Classes</B></A>'); } //--></SCRIPT><NOSCRIPT> <A HREF="../../allclasses-noframe.html"><B>All Classes</B></A></NOSCRIPT></FONT></TD></TR><TR><TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2"> SUMMARY: REQUIRED | <A HREF="#annotation_type_optional_element_summary">OPTIONAL</A></FONT></TD><TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2">DETAIL: <A HREF="#annotation_type_element_detail">ELEMENT</A></FONT></TD></TR></TABLE><A NAME="skip-navbar_top"></A><!-- ========= END OF TOP NAVBAR ========= --><HR><!-- ======== START OF CLASS DATA ======== --><H2><FONT SIZE="-1">javax.persistence</FONT><BR>Annotation Type DiscriminatorColumn</H2><HR><DL><DT><PRE><FONT SIZE="-1"><A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/annotation/Target.html" title="class or interface in java.lang.annotation">@Target</A>(<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/annotation/Target.html#value()" title="class or interface in java.lang.annotation">value</A>=<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/annotation/ElementType.html#TYPE" title="class or interface in java.lang.annotation">TYPE</A>)<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/annotation/Retention.html" title="class or interface in java.lang.annotation">@Retention</A>(<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/annotation/Retention.html#value()" title="class or interface in java.lang.annotation">value</A>=<A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/annotation/RetentionPolicy.html#RUNTIME" title="class or interface in java.lang.annotation">RUNTIME</A>)</FONT>public @interface <B>DiscriminatorColumn</B></DL></PRE><P>Is used to define the discriminator column for the <A HREF="../../javax/persistence/InheritanceType.html#SINGLE_TABLE"><CODE>SINGLE_TABLE</CODE></A> and <A HREF="../../javax/persistence/InheritanceType.html#JOINED"><CODE>JOINED</CODE></A> inheritance mapping strategies. <p> The strategy and the discriminator column are only specified in the root of an entity class hierarchy or subhierarchy in which a different inheritance strategy is applied <p> If the <code>DiscriminatorColumn</code> annotation is missing, and a discriminator column is required, the name of the discriminator column defaults to <code>"DTYPE"</code> and the discriminator type to <A HREF="../../javax/persistence/DiscriminatorType.html#STRING"><CODE>DiscriminatorType.STRING</CODE></A>. <pre> Example: @Entity @Table(name="CUST") @Inheritance(strategy=SINGLE_TABLE) @DiscriminatorColumn(name="DISC", discriminatorType=STRING,length=20) public class Customer { ... } @Entity public class ValuedCustomer extends Customer { ... } </pre><P><P><DL><DT><B>Since:</B></DT> <DD>Java Persistence 1.0</DD></DL><HR><P><!-- =========== ANNOTATION TYPE OPTIONAL MEMBER SUMMARY =========== --><A NAME="annotation_type_optional_element_summary"><!-- --></A><TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY=""><TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor"><TH ALIGN="left" COLSPAN="2"><FONT SIZE="+2"><B>Optional Element Summary</B></FONT></TH></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE> <A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A></CODE></FONT></TD><TD><CODE><B><A HREF="../../javax/persistence/DiscriminatorColumn.html#columnDefinition()">columnDefinition</A></B></CODE><BR> (Optional) The SQL fragment that is used when generating the DDL for the discriminator column.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE> <A HREF="../../javax/persistence/DiscriminatorType.html" title="enum in javax.persistence">DiscriminatorType</A></CODE></FONT></TD><TD><CODE><B><A HREF="../../javax/persistence/DiscriminatorColumn.html#discriminatorType()">discriminatorType</A></B></CODE><BR> (Optional) The type of object/column to use as a class discriminator.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE> int</CODE></FONT></TD><TD><CODE><B><A HREF="../../javax/persistence/DiscriminatorColumn.html#length()">length</A></B></CODE><BR> (Optional) The column length for String-based discriminator types.</TD></TR><TR BGCOLOR="white" CLASS="TableRowColor"><TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1"><CODE> <A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A></CODE></FONT></TD><TD><CODE><B><A HREF="../../javax/persistence/DiscriminatorColumn.html#name()">name</A></B></CODE><BR> (Optional) The name of column to be used for the discriminator.</TD></TR></TABLE> <P><A NAME="name()"><!-- --></A><H3>name</H3><PRE>public abstract <A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A> <B>name</B></PRE><DL><DD>(Optional) The name of column to be used for the discriminator.<P><DD><DL></DL></DD><DD><DL></DL><DL><DT><B>Default:</B><DD>"DTYPE"</DD></DL></DL><HR><A NAME="discriminatorType()"><!-- --></A><H3>discriminatorType</H3><PRE>public abstract <A HREF="../../javax/persistence/DiscriminatorType.html" title="enum in javax.persistence">DiscriminatorType</A> <B>discriminatorType</B></PRE><DL><DD>(Optional) The type of object/column to use as a class discriminator. Defaults to <A HREF="../../javax/persistence/DiscriminatorType.html#STRING"><CODE>DiscriminatorType.STRING</CODE></A>.<P><DD><DL></DL></DD><DD><DL></DL><DL><DT><B>Default:</B><DD>STRING</DD></DL></DL><HR><A NAME="columnDefinition()"><!-- --></A><H3>columnDefinition</H3><PRE>public abstract <A HREF="http://java.sun.com/j2se/1.5/docs/api/java/lang/String.html" title="class or interface in java.lang">String</A> <B>columnDefinition</B></PRE><DL><DD>(Optional) The SQL fragment that is used when generating the DDL for the discriminator column. <p> Defaults to the provider-generated SQL to create a column of the specified discriminator type.<P><DD><DL></DL></DD><DD><DL></DL><DL><DT><B>Default:</B><DD>""</DD></DL></DL><HR><A NAME="length()"><!-- --></A><H3>length</H3><PRE>public abstract int <B>length</B></PRE><DL><DD>(Optional) The column length for String-based discriminator types. Ignored for other discriminator types.<P><DD><DL></DL></DD><DD><DL></DL><DL><DT><B>Default:</B><DD>31</DD></DL></DL><!-- ========= END OF CLASS DATA ========= --><HR><!-- ======= START OF BOTTOM NAVBAR ====== --><A NAME="navbar_bottom"><!-- --></A><A HREF="#skip-navbar_bottom" title="Skip navigation links"></A><TABLE BORDER="0" WIDTH="100%" CELLPADDING="1" CELLSPACING="0" SUMMARY=""><TR><TD COLSPAN=2 BGCOLOR="#EEEEFF" CLASS="NavBarCell1"><A NAME="navbar_bottom_firstrow"><!-- --></A><TABLE BORDER="0" CELLPADDING="0" CELLSPACING="3" SUMMARY=""> <TR ALIGN="center" VALIGN="top"> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../overview-summary.html"><FONT CLASS="NavBarFont1"><B>Overview</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-summary.html"><FONT CLASS="NavBarFont1"><B>Package</B></FONT></A> </TD> <TD BGCOLOR="#FFFFFF" CLASS="NavBarCell1Rev"> <FONT CLASS="NavBarFont1Rev"><B>Class</B></FONT> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="package-tree.html"><FONT CLASS="NavBarFont1"><B>Tree</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../deprecated-list.html"><FONT CLASS="NavBarFont1"><B>Deprecated</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../index-all.html"><FONT CLASS="NavBarFont1"><B>Index</B></FONT></A> </TD> <TD BGCOLOR="#EEEEFF" CLASS="NavBarCell1"> <A HREF="../../help-doc.html"><FONT CLASS="NavBarFont1"><B>Help</B></FONT></A> </TD> </TR></TABLE></TD><TD ALIGN="right" VALIGN="top" ROWSPAN=3><EM></EM></TD></TR><TR><TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2"> <A HREF="../../javax/persistence/ColumnResult.html" title="annotation in javax.persistence"><B>PREV CLASS</B></A> <A HREF="../../javax/persistence/DiscriminatorType.html" title="enum in javax.persistence"><B>NEXT CLASS</B></A></FONT></TD><TD BGCOLOR="white" CLASS="NavBarCell2"><FONT SIZE="-2"> <A HREF="../../index.html?javax/persistence/DiscriminatorColumn.html" target="_top"><B>FRAMES</B></A> <A HREF="DiscriminatorColumn.html" target="_top"><B>NO FRAMES</B></A> <SCRIPT type="text/javascript"> <!-- if(window==top) { document.writeln('<A HREF="../../allclasses-noframe.html"><B>All Classes</B></A>'); } //--></SCRIPT><NOSCRIPT> <A HREF="../../allclasses-noframe.html"><B>All Classes</B></A></NOSCRIPT></FONT></TD></TR><TR><TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2"> SUMMARY: REQUIRED | <A HREF="#annotation_type_optional_element_summary">OPTIONAL</A></FONT></TD><TD VALIGN="top" CLASS="NavBarCell3"><FONT SIZE="-2">DETAIL: <A HREF="#annotation_type_element_detail">ELEMENT</A></FONT></TD></TR></TABLE><A NAME="skip-navbar_bottom"></A><!-- ======== END OF BOTTOM NAVBAR ======= --><HR><font size="-1"><a href="http://java.sun.com/webapps/bugreport">Submit a bug or feature</a> <p>Copyright 2007 Sun Microsystems, Inc. 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