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package org.apache.cayenne.dba.sqlserver;

import org.apache.cayenne.access.DataNode;
import org.apache.cayenne.access.trans.QualifierTranslator;
import org.apache.cayenne.access.trans.QueryAssembler;
import org.apache.cayenne.access.trans.TrimmingQualifierTranslator;
import org.apache.cayenne.dba.sybase.SybaseAdapter;
import org.apache.cayenne.map.DbAttribute;
import org.apache.cayenne.merge.MergerFactory;
import org.apache.cayenne.query.Query;
import org.apache.cayenne.query.SQLAction;

/**
 * Cayenne DbAdapter implementation for <a
 * href="http://www.microsoft.com/sql/"Microsoft SQL Server </a> engine.
 * </p>
 * <h3>Microsoft Driver Settings</h3>
 * <p>
 * Sample connection settings to use with MS SQL Server are shown below:
 * 
 * <pre>
 *       sqlserver.cayenne.adapter = org.apache.cayenne.dba.sqlserver.SQLServerAdapter
 *       sqlserver.jdbc.username = test
 *       sqlserver.jdbc.password = secret
 *       sqlserver.jdbc.url = jdbc:sqlserver://192.168.0.65;databaseName=cayenne;SelectMethod=cursor
 *       sqlserver.jdbc.driver = com.microsoft.sqlserver.jdbc.SQLServerDriver
 * </pre>
 * 
 * <p>
 * <i>Note on case-sensitive LIKE: if your application requires case-sensitive LIKE
 * support, ask your DBA to configure the database to use a case-senstitive collation (one
 * with "CS" in symbolic collation name instead of "CI", e.g.
 * "SQL_Latin1_general_CP1_CS_AS"). </i>
 * </p>
 * <h3>jTDS Driver Settings</h3>
 * <p>
 * jTDS is an open source driver that can be downloaded from <a href=
 * "http://jtds.sourceforge.net">http://jtds.sourceforge.net </a>. It supports both
 * SQLServer and Sybase. Sample SQLServer settings are the following:
 * </p>
 * 
 * <pre>
 * 
 *  
 *   
 *       sqlserver.cayenne.adapter = org.apache.cayenne.dba.sqlserver.SQLServerAdapter
 *       sqlserver.jdbc.username = test
 *       sqlserver.jdbc.password = secret
 *       sqlserver.jdbc.url = jdbc:jtds:sqlserver://192.168.0.65/cayenne
 *       sqlserver.jdbc.driver = net.sourceforge.jtds.jdbc.Driver
 *    
 *   
 *  
 * </pre>
 * 
 * @author Andrus Adamchik
 * @since 1.1
 */
public class SQLServerAdapter extends SybaseAdapter {

    public static final String TRIM_FUNCTION = "RTRIM";

    public SQLServerAdapter() {
        // TODO: i wonder if Sybase supports generated keys... 
        // in this case we need to move this to the super.
        this.setSupportsGeneratedKeys(true);
        this.setSupportsBatchUpdates(true);
    }
    

    /**
     * Uses SQLServerActionBuilder to create the right action.
     * 
     * @since 1.2
     */
    @Override
    public SQLAction getAction(Query query, DataNode node) {
        return query.createSQLAction(new SQLServerActionBuilder(this, node.getEntityResolver()));
    }

    
    /**
     * Returns a trimming translator.
     */
    @Override
    public QualifierTranslator getQualifierTranslator(QueryAssembler queryAssembler) {
        return new TrimmingQualifierTranslator(
                queryAssembler,
                SQLServerAdapter.TRIM_FUNCTION);
    }

    
    /**
     * Overrides super implementation to correctly set up identity columns.
     * 
     * @since 1.2
     */
    @Override
    protected void createTableAppendColumn(StringBuffer sqlBuffer, DbAttribute column) {
        super.createTableAppendColumn(sqlBuffer, column);
        
        if(column.isGenerated()) {
            // current limitation - we don't allow to set identity parameters...
            sqlBuffer.append(" IDENTITY (1, 1)");
        }
    }
    
    @Override
    public MergerFactory mergerFactory() {
        return new SQLServerMergerFactory();
    }
}
