ORACLE RETURNING INTO的用法

關於DML語句 INSERT,UPDATE,DELETE RETURNING INTO的測試結果

1.前提準備

 由於框架的原因 在得到PreparedStatement對象,強轉爲OraclePreparedStatement時會出現轉化報錯的問題,故不能使用強轉的方式

 應使用wPs1.unwrap(OraclePreparedStatement.class)的方式轉化爲OraclePreparedStatement對象

2.SQL的書寫

(1) DML的具體規則不變,只需在最後面加上 RETURNING COLUMN_NAME INTO :NAME NAME自定義.

例如: INSERT INTO A_TABLE(ID,NAME) VALUES ('1', '2') RETURNING ID INTO :R_ID
      UPDATE A_TABLE SET ID = '2' WHERE NAME = '2' RETURNING ID INTO :R_ID
      DELETE FROM A_TABLE WHERE NAME = '2' RETURNING ID INTO :R_ID

(2) 當需要返回多個字段時,最後面加上 RETURNING COLUMN_NAME1,COLUMN_NAME2… INTO :NAME1,:NAME2…

例如: INSERT INTO A_TABLE(ID,NAME) VALUES ('1', '2') RETURNING ID,NAME INTO :R_ID,:R_NAME
     UPDATE A_TABLE SET ID = '2' WHERE NAME = '2' RETURNING ID,NAME INTO :R_ID,:R_NAME
     DELETE FROM A_TABLE WHERE NAME = '2' RETURNING ID,NAME INTO :R_ID,:R_NAME   

3.JAVA代碼的編寫

 (1) sql中 '?'的下標和之前的賦值方式一致 wPs.setString(1, "123");
 (2) 對於INTO的字段在之前'?'下標的基礎上累加並使用wPs.registerReturnParameter(2, Types.INTEGER);的方式       	    賦值,第二個參數應該是返回值的類型(或者是字段的類型,在這我沒有深究)
 (3) 獲取返回的數據
     resultSet = wPs.getReturnResultSet();
     while (resultSet.next()) {
         System.out.println(resultSet.getString(1)); // 好像只能通過下標取值,不能通過別名
         System.out.println(resultSet.getString(2));
     }

4.代碼模板

public static void main(String[] args){
		String inSQL = "DELETE FROM A_TABLE WHERE ID = ? RETURNING ID,NAME INTO :R_ID,:R_NAME";
		Connection conn = null;
		String Driver = "oracle.jdbc.OracleDriver";
		String URL = "jdbc:oracle:thin:@127.0.0.1:1521:orcl";
		String USER = "scott";
		String Password = "tiger";
		OraclePreparedStatement wPs = null;
		PreparedStatement wPs1 = null;
		ResultSet resultSet = null;
 		try {
				Class.forName(Driver);
				conn =  DriverManager.getConnection(URL, USER, Password);
  			wPs1 = pHdl.prepareSqlStatement(inSQL);
  			wPs = wPs1.unwrap(OraclePreparedStatement.class);
  			wPs.setString(1, "123");
  			wPs.registerReturnParameter(2, Types.CHAR);
  			wPs.registerReturnParameter(3, Types.CHAR);
  			wPs.executeUpdate();
  			resultSet = wPs.getReturnResultSet();
  			while (resultSet.next()) {
  					System.out.println(resultSet.getString(1));
  					System.out.println(resultSet.getString(2));
  			}
 		} catch (SQLException e) {
  				return;
 		} finally {
  				// 關閉資源
  				...
    }
}