c# 取数据库中特定的值

[destinyC]

string sql = "SELECT USERINFO.USERNAME FROM USERINFO WHERE UESERID='" + uid + "'";
我想取出表USERINFO中USERID=uid时的USERNAME。
请问大虾用声明语句实现取

[wheeler]

declare @uid int
set @uid = 'xxxxxx'
SELECT USERNAME FROM USERINFO WHERE UESERID = @uid

这样？


'用声明语句实现取' 这句话真的看不懂

[wwweasy]

看不明白，楼主要达到什么目的

[缭绕飘渺]

楼主是意思是不是怎么执行你那个sql语句
然后返回那个结果赋给一个字符串啊

[destinyC]

请问大虾用C#语句实现取。。。
打错字了。。

TO
mervyn807

就是那个意思 我本来想用SqlDataReader但是没实现的了

[lpingz]

string queryString = "SELECT USERINFO.USERNAME FROM USERINFO WHERE UESERID='" + uid + "'";
    using (OracleConnection connection = new OracleConnection(connectionString))
    {
        OracleCommand command = new OracleCommand(queryString, connection);
        connection.Open();
        MySqlDataAdapter mysqlda = new MySqlDataAdapter(command, connection);
        DataSet dataset = new DataSet();
        mysqlda.Fill(dataset, "tablename");
        if(dataset != null)
       {
            DataTable dt = dataset.Tables["tablename"];
            string username = dt.Rows[0][0].ToString();
       }

大概这个意思，手写没调试@-@