讓java從Mysql返回多個ResultSet

首先，JDBC對於SQLSERVER來說默認是支持返回，但對於MySql來說，只默認支持存儲過程返回多個ResultSet，那對於手寫SQL怎麼辦。

其實很簡單，只要一個在連接字符串中加一個參數：allowMultiQueries=true。

代碼實現如下：

@Test
public void test01() throws SQLException, ClassNotFoundException {
    String DBDRIVER = "com.mysql.jdbc.Driver";
    String DBURL = "jdbc:mysql://localhost:3306/bookstore?allowMultiQueries=true";
    String DBUSER = "root";
    String DBPASS = "root";

    Connection conn = null; 
    Class.forName(DBDRIVER); 
    conn = DriverManager.getConnection(DBURL, DBUSER, DBPASS); 
    System.out.println(conn);
    String sql = "SELECT * FROM category;"
            +"SELECT * FROM user;" ;
    Statement stmt = conn.createStatement();

    boolean isResultSet = stmt.execute(sql);
    ResultSet rs = null;
    int count = 0;
    while(true) {
        if(isResultSet) {
            rs = stmt.getResultSet();
            while(rs.next()) {
                System.out.println(rs.getString(1));
            }
            rs.close();
        } else {
            if(stmt.getUpdateCount() == -1) {
                break;
            }
            System.out.printf("Result {} is just a count: {}", count, stmt.getUpdateCount());
        }

        count ++;
        isResultSet = stmt.getMoreResults();
    }
    stmt.close();
    conn.close(); 
}