Version.java

package database;

/************************************************
 * Not used yet, but when we start having releases, we will need to
 * to update old databases
 */
import java.sql.ResultSet;

import database.DBConn;
import util.ErrorReport;
import util.Globals;

public class Version {
	
	public Version (DBConn mDB) { 
		checkVersion(mDB);
		if (!version.equals(Globals.VERSION)) {
			System.out.println("DB version " + version + " new schema is " + Globals.VERSION);
			updateDB();
		}
	}
	public String getVersion () {return version;}
	
	// all new columns and tables are checked here and added if not exists
	// new columns and tables are also put into Schema.java
	private void updateDB() {
		System.out.println("No DB update");
	}
	private void checkVersion(DBConn mDB) {
		try {
			ResultSet rs = mDB.executeQuery("SELECT version from metaData");
			if (rs.next()) version = rs.getString(1);
			rs.close();
		}
		catch (Exception e){
			ErrorReport.die(e, "Cannot get version");
		}
	}
	private boolean hasTable(DBConn mDB, String name) throws Exception
	{
		ResultSet rs = mDB.executeQuery("show tables like '" + name + "'");
		boolean retVal = rs.first();
		rs.close();
		return retVal;
	}
	private boolean hasColumn(DBConn mDB, String table, String column) throws Exception
	{
		ResultSet rs = mDB.executeQuery("show columns from " + table + " where field='" + column + "'");
		boolean ret = rs.first();
		rs.close();
		return ret;
	}
	String version=null;
}