Java 如何从单个CallableStatement获取多个resultset？

当我从命令行调用存储的proc时，我得到以下结果

CALL `events`.`get_event_by_id`(10)

+---------+----------+-------------+---------------------+---------------------+---------------------+--------+----------+
| evet_id | name     | description | starttime           | endtime             | last_modified       | active | addre_id |
+---------+----------+-------------+---------------------+---------------------+---------------------+--------+----------+
|      10 | samole 3 | sanely      | 2013-11-27 17:37:00 | 2013-11-27 18:09:00 | 2013-11-27 09:37:42 |      1 |       20 |
+---------+----------+-------------+---------------------+---------------------+---------------------+--------+----------+
1 row in set (0.00 sec)

+---------+------------+---------+
| user_id | username   | picture |
+---------+------------+---------+
|       1 | jamess2000 | NULL    |
|       2 | yferna2012 | NULL    |
+---------+------------+---------+
2 rows in set (0.00 sec)

+----------+------------------------------+---------------------+-------------+--------+
| addre_id | street                       | name                | description | active |
+----------+------------------------------+---------------------+-------------+--------+
|       20 | Schieffelin                  | Manhattan Ville Loc | NULL        |      1 |
+----------+------------------------------+---------------------+-------------+--------+

下面是我的Java代码片段

String SP_GET_EVENT_BY_ID = "CALL `events`.`get_event_by_id`(?)";
String PROC_PARAM_EVENT_ID = "evet_id";
mCallableStatement = mConnection.prepareCall(SP_GET_EVENT_BY_ID);
mCallableStatement.setInt(10, PROC_PARAM_EVENT_ID);

当我执行该语句时，只返回event_table结果。 我阅读了以下内容的查询：

ResultSet reader = mCallableStatement.executeQuery();

while(reader.next())
{
   //etc..... here i assign db values to properties. 
}

我试图避免向数据库发出多个请求，因为根据结果的多少，它的速度非常慢，为300毫秒

---

有可能吗？

我找到了这篇很棒的文章

/**
 * MySqlCallMultipleResultSet.java
 * Copyright (c) 2007 by Dr. Herong Yang. All rights reserved.
 */
import java.sql.*;
public class MySqlCallMultipleResultSet {
  public static void main(String [] args) {
    Connection con = null;
    try {
      com.mysql.jdbc.jdbc2.optional.MysqlDataSource ds 
        = new com.mysql.jdbc.jdbc2.optional.MysqlDataSource();
      ds.setServerName("localhost");
      ds.setPortNumber(3306);
      ds.setDatabaseName("HerongDB");
      ds.setUser("Herong");
      ds.setPassword("TopSecret");
      con = ds.getConnection();

// Create CallableStatement
      CallableStatement cs = con.prepareCall("CALL HeadTail(?)");

// Register OUT parameters
      cs.registerOutParameter(1, java.sql.Types.INTEGER);     

// Execute the CALL statement and expecting multiple result sets
      boolean isResultSet = cs.execute();

// First ReulstSet object
      if (!isResultSet) {
        System.out.println("The first result is not a ResultSet.");
        return;
      }

// First ReulstSet object
      System.out.println("Head of the table:");
      ResultSet res = cs.getResultSet();
      while (res.next()) {
        System.out.println("  "+res.getInt("ID")
          +", "+res.getString("FirstName")
          +", "+res.getString("LastName")
          +", "+res.getTimestamp("ModTime"));

      }
      res.close();

// Move to the next result
      isResultSet = cs.getMoreResults();
      if (!isResultSet) {
        System.out.println("The next result is not a ResultSet.");
        return;
      }

// Second ReulstSet object
      System.out.println("Tail of the table:");
      res = cs.getResultSet();
      while (res.next()) {
        System.out.println("  "+res.getInt("ID")
          +", "+res.getString("FirstName")
          +", "+res.getString("LastName")
          +", "+res.getTimestamp("ModTime"));

      }
      res.close();

// Retrieve OUT parameters
      System.out.println("Total number of records: "+cs.getInt(1));

// Close resource
      cs.close();

      con.close();
    } catch (Exception e) {
      System.err.println("Exception: "+e.getMessage());
      e.printStackTrace();
    }
  }
}

下面是那篇文章的代码

/**
 * MySqlCallMultipleResultSet.java
 * Copyright (c) 2007 by Dr. Herong Yang. All rights reserved.
 */
import java.sql.*;
public class MySqlCallMultipleResultSet {
  public static void main(String [] args) {
    Connection con = null;
    try {
      com.mysql.jdbc.jdbc2.optional.MysqlDataSource ds 
        = new com.mysql.jdbc.jdbc2.optional.MysqlDataSource();
      ds.setServerName("localhost");
      ds.setPortNumber(3306);
      ds.setDatabaseName("HerongDB");
      ds.setUser("Herong");
      ds.setPassword("TopSecret");
      con = ds.getConnection();

// Create CallableStatement
      CallableStatement cs = con.prepareCall("CALL HeadTail(?)");

// Register OUT parameters
      cs.registerOutParameter(1, java.sql.Types.INTEGER);     

// Execute the CALL statement and expecting multiple result sets
      boolean isResultSet = cs.execute();

// First ReulstSet object
      if (!isResultSet) {
        System.out.println("The first result is not a ResultSet.");
        return;
      }

// First ReulstSet object
      System.out.println("Head of the table:");
      ResultSet res = cs.getResultSet();
      while (res.next()) {
        System.out.println("  "+res.getInt("ID")
          +", "+res.getString("FirstName")
          +", "+res.getString("LastName")
          +", "+res.getTimestamp("ModTime"));

      }
      res.close();

// Move to the next result
      isResultSet = cs.getMoreResults();
      if (!isResultSet) {
        System.out.println("The next result is not a ResultSet.");
        return;
      }

// Second ReulstSet object
      System.out.println("Tail of the table:");
      res = cs.getResultSet();
      while (res.next()) {
        System.out.println("  "+res.getInt("ID")
          +", "+res.getString("FirstName")
          +", "+res.getString("LastName")
          +", "+res.getTimestamp("ModTime"));

      }
      res.close();

// Retrieve OUT parameters
      System.out.println("Total number of records: "+cs.getInt(1));

// Close resource
      cs.close();

      con.close();
    } catch (Exception e) {
      System.err.println("Exception: "+e.getMessage());
      e.printStackTrace();
    }
  }
}

---

根据的Javadocs，您还应该检查getUpdateCount！=-1查找更多结果集时

这段代码适用于Sybase和许多其他数据库：

    try (Connection conn = DriverManager.getConnection(url, username, password);) {
        Class.forName("com.sybase.jdbc4.jdbc.SybDriver");
        CallableStatement call = conn.prepareCall("{call events.get_event_by_id(?)}");
        call.setInt("@evet_id", 10);
        boolean moreResults = call.execute();
        int updateCount = call.getUpdateCount();    
        while (moreResults || updateCount != -1) {
            if (moreResults) {
                ResultSet rs = call.getResultSet();
                processResults(rs);    
            }
            moreResults = call.getMoreResults();
            updateCount = call.getUpdateCount();
        }
    } catch (Exception e) {
        e.printStackTrace();
    }