为什么两个 类似 Connection conn = DriverManager.getConnection(),第二个会执行错误
为什么两个 类似 Connection conn = DriverManager.getConnection(),第二个会执行错误,具体代码如下:
try (
Connection conn = DriverManager.getConnection(url, user, pass); // 使用Connection来创建一个Statment对象
Statement stmt = conn.createStatement()
) {
String sql;
sql = "select user from user where user= 'mima_1aadb_1nb_2bbb' ";
//1、以上代码查询数据库中是否有一名为mima_1aadb_1nb_2bbb 的 user
ResultSet relt = stmt.executeQuery(sql);
if (!(relt.next())) {
sql = "create user 'mima_1aadb_1nb_2bbb'@'%' identified by '123' ";
// 2、 如果没有 mima_1aadb_1nb_2bbb 则创建该 user
stmt.executeUpdate(sql);
} else {
sql = "drop user mima_1aadb_1nb_2bbb "; // 3、 如果有则先删除 再 创建该 mima_1aadb_1nb_2bbb 帐户
stmt.executeUpdate(sql);
sql = "create user 'mima_1aadb_1nb_2bbb '@'%' identified by '123' ";
stmt.executeUpdate(sql);
}
sql = "grant select, alter ,delete, update , insert ,lock tables, show view on dbsj_nb_yj190801.* to 'mima_1aadb_1nb_2bbb '@'%' "; // 4、给该 帐户 授权
stmt.executeUpdate(sql);
sql = "select user from user where user='mima_1aadb_1nb_2bbb'";
relt = stmt.executeQuery(sql);
if (relt.next()) {
url1 = "jdbc:mysql://localhost:3306/dbsj_nb_yj190801?useSSL=false&serverTimezone=UTC";
pass1="123";
Connection conn1 = DriverManager.getConnection(url1, "mima_1aadb_1nb_2bbb", pass1);
// 5、执行到此处发生错误,错误代码不明,请问是何原因?
}
以上代码 中 dbsj_nb_yj190801 数据库存在 ,dbsj_nb_yj190801 建好之后,曾在MYSQL 命令行代码下 进行登录 测试,可正常登录
请问为什么 执行到5 处就出现错误。谢谢大家。