如何判断数据库中是否存在一个数据表

方法是通过查询数据库meta数据来获取数据表。

public static Boolean doesTableExist(String tablename) {
        Connection con = null;
        HashSet<String> set = new HashSet<String>();
        try {
            Class.forName(DatabaseConnection.getDatabaseConnection());
            con = DriverManager.getConnection(DatabaseName.con);
            DatabaseMetaData meta = con.getMetaData();
            ResultSet res = meta.getTables(null, null, null,
                    new String[]{"TABLE"});
            while (res.next()) {
                set.add(res.getString("TABLE_NAME"));
            }
            res.close();
            con.close();
        } catch (Exception e) {
            System.err.println("Exception: " + e.getMessage());
        }
        //System.out.println(set);
        return set.contains(tablename.toUpperCase());
    }

其中只需要替换DatabaseConnection.getDatabaseConnection()
和DatabaseName.con
为你需要连接的数据库就好了。可以参考另一篇文章如何连接埠通的数据库：http://blog.csdn.net/autofei/archive/2010/05/24/5621274.aspx



另外一个方法就是尝试连接数据库，然后捕获异常。

//connection = new DatabaseConnection(DatabaseConnection.DERBY, "", "db",	"uncc", "uncc");
		connection = new DatabaseConnection(DatabaseConnection.POSTGRES, "localhost", "postgres",
				"postgres", "postgres");
		database = new Database(connection);
	
		// Checks to see if database structure already exists
		boolean exists = true;
		Statement stmt = connection.getStatement();
		try {
			stmt.executeQuery("SELECT * FROM qgram");
		} catch (Exception e) {
			connection.rollback();
			exists = false;
		}

参考：http://www.herongyang.com/jdbc/JDBC-ODBC-Flat-File-List-Tables.html