SQL语句到底什么地方有错误呢?新手问题!急 update QiuZu set flag=1你这样会把整个QiuZu都更新的,没有加条件啊 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 try:SqlConnection conn = new SqlConnection("Data Source=127.0.0.1;Password=1314521;User ID=sa;Initial Catalog=Search;"); SqlCommand cmd=new SqlCommand("update QiuZu set flag=1",conn); cmd.Connection.Open(); cmd.ExecuteNonQuery();cmd.Connection.Close(); con.ConnectionString = sysconnstr;??sysconnstr = "Data Source=127.0.0.1;Password=1314521;User ID=sa;Initial Catalog=Search;"??? SqlCommand cmd=new SqlCommand("update QiuZu set flag=1",conn); SqlConnection con = new SqlConnection("Data Source=127.0.0.1;Password=1314521;User ID=sa;Initial Catalog=Search;");con.ConnectionString = sysconnstr;上面你把con实例了,你又给他赋sysconnstr这个变量的连接字符串,而且不知道sysconnstr是什么。建议你用try...catch 来调试。 你在实例化 SqlConnection 时不是把连接字符串传进去了吗?干嘛还要 con.ConnectionString = sysconnstr;打开连接的时候最好放在try{}catch{}块里 update QiuZu set flag=1 where id=1// ?? try{ string sysconnstr="Data Source=127.0.0.1;Password=1314521;User ID=sa;Initial Catalog=Search"; string sql ="update QiuZu set flag=1"; SqlConnection con = new SqlConnection(); SqlCommand com = new SqlCommand(sql,con); com.ExecuteNonQuery(); com.Dispose(); con.Close(); con.Dispose(); con.ConnectionString = sysconnstr; 错了 con.ConnectionString = sysconnstr;是什么道理 SqlConnection con = new SqlConnection("Data Source=127.0.0.1;Password=1314521;User ID=sa;Initial Catalog=Search;"); con.Open(); SqlCommand com = new SqlCommand(); com.Connection = con; com.CommandText = "update QiuZu set flag=1"; com.ExecuteNonQuery(); com.Dispose(); con.Close(); con.Dispose(); con.ConnectionString = sysconnstr; 错了~!!最好加个 try{ 你的原代码}catch(Exception error){ MessageBox.show(error.message);}这样至少能看到你到底是哪里错了 ~!! con.ConnectionString = sysconnstr; //sysconnstr变量未定义;是拷贝来的代码吧?那就是没有拷贝完全 SqlConnection con = new SqlConnection("Data Source=127.0.0.1;Password=1314521;User ID=sa;Initial Catalog=Search;"); con.ConnectionString = sysconnstr; con.Open(); SqlCommand com = new SqlCommand(); com.Connection = con; com.CommandText = "update QiuZu set flag='1'"; com.ExecuteNonQuery(); com.Dispose(); con.Close(); con.Dispose(); 要找到出错的原因,肯定是要:try{上面的代码...}catch(Exception exp){string strExp = exp.Message.ToString();}在catch中找到原因吧。 new SqlConnection("Data Source=127.0.0.1;Password=1314521;User ID=sa;Initial Catalog=Search;");里的database到哪里去了?datascourse写.就可以了con.ConnectionString = sysconnstr;这句完全是多余的 SqlConnection con = new SqlConnection("Data Source=127.0.0.1;Password=1314521;User ID=sa;Initial Catalog=Search;"); String sysconnstr="Persist Security Info=False;Integrated Security=SSPI;database=mydatabase;server=."; con.ConnectionString = sysconnstr; con.Open(); SqlCommand com = new SqlCommand(); com.Connection = con; com.CommandText = "update QiuZu set flag=1"; com.ExecuteNonQuery(); com.Dispose(); con.Close(); con.Dispose(); SqlConnection con = new SqlConnection("Data Source=127.0.0.1;Password=1314521;User ID=sa;Initial Catalog=Search;"); con.ConnectionString = sysconnstr;-----------------------------------------------------------------------------------可能是这里的问题. sysconnstr 在哪里声明??存储的什么内容..SqlConnection con = new SqlConnection("Data Source=127.0.0.1;Password=1314521;User ID=sa;Initial Catalog=Search;");就已经表示你把"Data Source=127.0.0.1;Password=1314521;User ID=sa;Initial Catalog=Search;" 这个字符串传常量给con做ConnectionString属性了,所以:con.ConnectionString = sysconnstr;就是多余的,如果sysconnstr没存储任何内容的话,可能就是它的错了 【求教】无法将类型为“System.DateTime”的对象强制转换为类型“System.String”。 C# 100分求读出access的ole对象的问题,希望朋友们能帮帮忙 新手提问 超难问题:在winform中,如何能知道鼠标移动到了datagrid中的哪一列? 关于分类的数据帮定 初学者请教问题,请大家帮忙 静态非托管引用DLL 卸载 删除(改) 请问用Visual Studio.Net作开发时应怎样进行分工合作呢? [提问] c#开发涉及到图形按钮的问题 做网络通讯,怎么设计数据安全解决方案? win ce打印程序 小妹在这里求助各位大虾 帮忙到底啊!
SqlConnection conn = new SqlConnection("Data Source=127.0.0.1;Password=1314521;User ID=sa;Initial Catalog=Search;");
SqlCommand cmd=new SqlCommand("update QiuZu set flag=1",conn);
cmd.Connection.Open();
cmd.ExecuteNonQuery();
cmd.Connection.Close();
con.ConnectionString = sysconnstr;
上面你把con实例了,你又给他赋sysconnstr这个变量的连接字符串,而且不知道sysconnstr是什么。
建议你用try...catch 来调试。
干嘛还要 con.ConnectionString = sysconnstr;
打开连接的时候
最好放在
try{}catch{}块里
{
string sysconnstr="Data Source=127.0.0.1;Password=1314521;User ID=sa;Initial Catalog=Search";
string sql ="update QiuZu set flag=1";
SqlConnection con = new SqlConnection();
SqlCommand com = new SqlCommand(sql,con);
com.ExecuteNonQuery();
com.Dispose();
con.Close();
con.Dispose();
con.Open(); SqlCommand com = new SqlCommand();
com.Connection = con;
com.CommandText = "update QiuZu set flag=1";
com.ExecuteNonQuery();
com.Dispose(); con.Close(); con.Dispose();
你的原代码
}
catch(Exception error)
{
MessageBox.show(error.message);
}这样至少能看到你到底是哪里错了 ~!!
con.ConnectionString = sysconnstr;
con.Open(); SqlCommand com = new SqlCommand();
com.Connection = con;
com.CommandText = "update QiuZu set flag='1'";
com.ExecuteNonQuery();
com.Dispose(); con.Close(); con.Dispose();
try
{上面的代码...}
catch(Exception exp)
{string strExp = exp.Message.ToString();}
在catch中找到原因吧。
con.ConnectionString = sysconnstr;这句完全是多余的
String sysconnstr="Persist Security Info=False;Integrated Security=SSPI;database=mydatabase;server=.";
con.ConnectionString = sysconnstr;
con.Open(); SqlCommand com = new SqlCommand();
com.Connection = con;
com.CommandText = "update QiuZu set flag=1";
com.ExecuteNonQuery();
com.Dispose(); con.Close(); con.Dispose();
con.ConnectionString = sysconnstr;
-----------------------------------------------------------------------------------
可能是这里的问题.
SqlConnection con = new SqlConnection("Data Source=127.0.0.1;Password=1314521;User ID=sa;Initial Catalog=Search;");
就已经表示你把"Data Source=127.0.0.1;Password=1314521;User ID=sa;Initial Catalog=Search;" 这个字符串传常量给con做ConnectionString属性了,所以:
con.ConnectionString = sysconnstr;就是多余的,
如果sysconnstr没存储任何内容的话,可能就是它的错了