【原创】Java中数据库处理的自定义方法库

1.postgres数据库的select操作，返回select后返回的第一行数据,返回类型为string,若要返回int,只需将getString改为getInt

 public static String PgDBSelect(String sql) throws ClassNotFoundException, SQLException{
  String dbURL="jdbc:postgresql://172.16.4.25:5432/skyups";
  String dbuser="***";
  String dbpasswd="***";
  Class.forName("org.postgresql.Driver");
  Connection conn = DriverManager.getConnection(dbURL,dbuser,dbpasswd);
  Statement stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_READ_ONLY);
     ResultSet rs = stmt.executeQuery(sql);
     rs.next();
     String value=rs.getString(1);
     rs.close();
     stmt.close();
     conn.close();
     return value;
 }

2.postgres数据的执行操作，可执行instert、delete、update等操作，不返回数据
 public static void PgDBUpdate(String sql) throws ClassNotFoundException, SQLException{
  String dbURL="jdbc:postgresql://172.16.4.25:5432/skyups";
  String dbuser="***";
  String dbpasswd="***";
  Class.forName("org.postgresql.Driver");
  Connection conn = DriverManager.getConnection(dbURL,dbuser,dbpasswd);
  Statement stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_UPDATABLE);
     stmt.executeUpdate(sql);
     stmt.close();
     conn.close();
 }

3.oracle数据库的select操作，返回select后返回的第一行数据,若要返回int,只需将getString改为getInt

 public static String OracleDBSelect(String sql) throws ClassNotFoundException, SQLException{
  String dbURL="jdbc:oracle:thin:@172.16.4.21:1521:skytest";
  String dbuser="***";
  String dbpasswd="***";
  Class.forName("oracle.jdbc.OracleDriver");
  Connection conn = DriverManager.getConnection(dbURL,dbuser,dbpasswd);
  Statement stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_READ_ONLY);
     ResultSet rs = stmt.executeQuery(sql);
     rs.next();
     int expbalance=rs.getString(1);
     rs.close();
     stmt.close();
     conn.close();
     return expbalance;
 }

4.oralce数据的执行操作，可执行instert、delete、update等操作，不返回数据
 public static void OracleDBUpdate(String sql) throws ClassNotFoundException, SQLException{
  String dbURL="jdbc:oracle:thin:@172.16.4.21:1521:skytest";
  String dbuser="***";
  String dbpasswd="***";
  Class.forName("oracle.jdbc.OracleDriver");
  Connection conn = DriverManager.getConnection(dbURL,dbuser,dbpasswd);
  Statement stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_UPDATABLE);
     stmt.executeUpdate(sql);
     stmt.close();
     conn.close();
 }

5.Cassandra非关系型数据库的操作，包括delete、insert、read等。
 public static void CassandraRemove(String USkyid)throws IllegalStateException, PoolExhaustedException,Exception {
  CassandraClientPool pool = CassandraClientPoolFactory.INSTANCE.get();
  CassandraClient client = pool.borrowClient("172.16.4.244", 9160);
  try{
        Keyspace keyspace = client.getKeyspace("skyups");
        ColumnPath columnPath = new ColumnPath();
        columnPath.setColumn_family("UserInfo"); 
        //delete
        keyspace.remove(USkyid, columnPath);
        /*
        // read
        Column col = keyspace.getColumn(value, columnPath);
        System.out.println("Read from cassandra: " + string(col.getValue()));
        // insert
        keyspace.insert("key", columnPath, bytes("value"));
        */
  } finally{
   pool.releaseClient(client);  
   }
  }