我有以下代码:
public boolean updateDatabase(long houseValue, List<Users> userList)
{
boolean result = false;
Connection conn = null;
PreparedStatement stmtUpdateUsers = null;
PreparedStatement stmtQueryHouse = null;
PreparedStatement stmtUpdateHouse = null;
ResultSet rs = null;
String updateUsers = "UPDATE users SET money = ? WHERE username = ?";
String queryHouse = "SELECT * FROM house WHERE house_id = ?";
String updateHouse = "UPDATE house SET house_money = ? WHERE house_id = ?";
try
{
conn = getConnectionPool().getConnection();
conn.setAutoCommit(false);
stmtUpdateUsers = conn.prepareStatement(updateUsers);
...
// Here is some code that updates Users table in a short loop
...
stmtQueryHouse = conn.prepareStatement(queryHouse);
stmtQueryHouse.setInt(1, 1);
rs = stmtQueryHouse.executeQuery();
if(rs.next())
{
long houseMoney = rs.getLong("house_money");
houseMoney += houseValue;
stmtUpdateHouse = conn.prepareStatement(updateHouse);
stmtUpdateHouse.setLong(1, houseMoney);
stmtUpdateHouse.setInt(2, 1);
stmtUpdateHouse.executeUpdate();
}
else
{
throw new SQLException("Failed to update house: unable to query house table");
}
conn.commit();
result = true;
}
catch(SQLException e)
{
logger.warn(getStackTrace(e));
try{conn.rollback();}catch(SQLException excep)
{
logger.warn(getStackTrace(excep));
}
}
finally
{
DbUtils.closeQuietly(rs);
DbUtils.closeQuietly(stmtQueryHouse);
DbUtils.closeQuietly(stmtUpdateUsers);
DbUtils.closeQuietly(stmtUpdateHouse);
try { conn.setAutoCommit(true); } catch (SQLException e) { /* quiet */ }
DbUtils.closeQuietly(conn);
}
return result
}
此方法可以从多个线程调用,house 表只是一个包含总收入的单行表。它由不同的线程更新。
问题是 stmtQueryHouse.executeQuery() 返回空集,这不应该发生,因为 house 表总是有(自数据库创建以来)更新的一行(仅更新 house_money 列)。
当我在 Windows(JDBC 驱动程序 + mysql 5.5.13)上运行这段代码时,它工作正常,但是当我在 CentOS(相同的 JDBC 驱动程序 + mysql 5.1.57)上运行它时,它经常返回空结果集(如果不是总是)。知道出了什么问题或我如何检查问题出在哪里?也许我应该使用 select 进行更新,但为什么它适用于 Windows 而不是 Linux?我感谢任何帮助。提前致谢。
最佳答案
查看 mysql 通用查询日志是否有任何错误?
我知道这本身不是你的问题,但如果你有另一个表,每个房子只有一行,我觉得将 house_money
移到你的主表中会更有意义房子
表
关于java - Mysql+JDBC+Linux : executeQuery returns empty result set when it shouldn't,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/6658362/