dbinformix.java

另外一种持久性o/m软件

package org.apache.torque.adapter;

/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License")
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;

/**
 * This code should be used for an Informix database pool.
 *
 * @author <a href="mailto:[e-mail]">Jon S. Stevens</a>
 * @author <a href="mailto:[e-mail]">Brian P Millett</a>
 * @version $Id: DBInformix.java,v 1.8 2005/01/31 19:43:55 tfischer Exp $
 */
public class DBInformix extends DB
{
    /**
     * Empty constructor.
     */
    protected DBInformix()
    {
    }

    /**
     * This method is used to ignore case.  Problem is that Informix
     * does not have an UPPER function.  So the best would be to do
     * nothing.
     *
     * @param in The string to transform to upper case.
     * @return The upper case string.
     */
    public String toUpperCase(String in)
    {
        return in;
    }

    /**
     * This method is used to ignore case.  Problem is that Informix
     * does not have an UPPER function.  So the best would be to do
     * nothing.
     *
     * @param in The string whose case to ignore.
     * @return The string in a case that can be ignored.
     */
    public String ignoreCase(String in)
    {
        return in;
    }

    /**
     * @see org.apache.torque.adapter.DB#getIDMethodType()
     */
    public String getIDMethodType()
    {
        return NO_ID_METHOD;
    }

    /**
     * @see org.apache.torque.adapter.DB#getIDMethodSQL(Object obj)
     */
    public String getIDMethodSQL(Object obj)
    {
        return null;
    }

    /**
     * The method is used to lock a table.
     *
     * @param con The JDBC connection to use.
     * @param table The name of the table to lock.
     * @exception SQLException No Statement could be created or executed.
     */
    public void lockTable(Connection con, String table) throws SQLException
    {
        Statement statement = con.createStatement();

        StringBuffer stmt = new StringBuffer();
        stmt.append("LOCK TABLE ")
        .append(table)
        .append(" IN EXCLUSIVE MODE");

        statement.executeQuery(stmt.toString());
    }

    /**
     * The method is used to unlock a table.
     *
     * @param con The JDBC connection to use.
     * @param table The name of the table to unlock.
     * @exception SQLException No Statement could be created or executed.
     */
    public void unlockTable(Connection con, String table) throws SQLException
    {
        // Tables in Informix are unlocked when a commit is issued.
        // The user may have issued a commit but do it here to be
        // sure.
        con.commit();
    }
}