mysql - 在没有同步错误的情况下在另一个循环中运行 mysql 查询

Question

如果我有这样的代码(忽略初始化连接和句柄等不相关的事情):

MYSQL_RES *res;
MYSQL_ROW row;
mysql_query(mysql, "some select query");
res = mysql_use_result(mysql);
while (row = mysql_fetch_row(res)) {
    MYSQL_RES *res2;
    MYSQL_ROW row2;
    mysql_query(mysql, "some other select query using an id from the first");
    res2 = mysql_use_result(mysql);
    /* ... */
    mysql_free_result(res2);
}
mysql_free_result(res);

每当我运行第二个 mysql_query(在循环中)时，我都会收到错误

mysql: 2014: Commands out of sync; you can't run this command now

如何在从一个选择查询中获取行的同时运行另一个选择查询？

Answer 1

我向 MySQL 邮件列表发送了一封电子邮件。基本上，为了能够做到这一点，我需要有两个独立的 MySQL 连接。谢谢，Shawn Green(来自 Oracle)。

The mysql object you are using for your connection can only have one active query or result on it at a time. To have two sets of results working, you need a second independent connection to the MySQL server