SqlParameter用法

拼搏现实的明天。 2022-09-19 04:20 111阅读 0赞

在c\#中执行sql语句时传递参数的小经验

1、直接写入法：

例如：

int Id =1;

string Name="lui";

cmd.CommandText="insert into TUserLoginvalues("+Id+",'"+Name+"')";

因为Id是数值，所以在传递的时候只需要在sql字符串中用"+Id+"即可实现，而  Name是字符串，所以在传递的时候还需要在"+Name+"两边各加一个单引号（'）来 实现;

2、给命令对象添加参数法：

例如：

int Id =1;

string Name="lui";

cmd.CommandText="insert into TUserLogin values(@Id,@Name)";

//上条语句中直接在sql语句中写添加的参数名,不论参数类型都是如此.

SqlParameter  para=newSqlParameter("@Id",SqlDbType.int,4);//生成一个名字为@Id的参数,必须以@开头表示是添加的参数，并设置其类型长度，类型长度与数据库中对应字段相同

para.Value=Id;//给参数赋值

cmd.Parameters.Add(para);//必须把参数变量添加到命令对象中去。

//以下类似

para=new SqlParameter("@Name",SqlDbType.VarChar,16);

para.Value=Name;

com.Parameters.Add(para);

...然后就可以执行数据库操作了。  
\-----------------------------------  
3、

SqlParameter\[\] paraList = new SqlParameter\[7\];  
  
paraList\[0\] = new SqlParameter( "@userName ", SqlDbType.VarChar,50);  
paraList\[0\].Value = personModel.UserName;  
paraList\[1\] = new SqlParameter( "@account ", SqlDbType.VarChar,100);  
paraList\[1\].Value = personModel.Account;  
paraList\[2\] = new SqlParameter( "@pwd ", SqlDbType.VarChar,100);  
paraList\[2\].Value = personModel.Pwd;  
paraList\[3\] = new SqlParameter( "@unitID ", SqlDbType.VarChar,20);  
paraList\[3\].Value = personModel.UnitID;  
paraList\[4\] = new SqlParameter( "@email ", SqlDbType.VarChar,100);  
paraList\[4\].Value = personModel.Email;  
paraList\[5\] = new SqlParameter( "@officeTel ", SqlDbType.VarChar,20);  
paraList\[5\].Value = personModel.OfficeTel;  
paraList\[6\] = new SqlParameter( "@mobile ", SqlDbType.VarChar,20);  
paraList\[6\].Value = personModel.Mobile;  
  
return sd.ExecuteNonQuery( "UP\_Person\_ADD ", paraList); ///        SqlParameter\[\] parms = new SqlParameter\[\] \{   
                   new SqlParameter(SQL\_PARM\_RECEIVE, SqlDbType.NVarChar,20),  
                   new SqlParameter(SQL\_PARM\_SEND, SqlDbType.NVarChar,20),  
                   new SqlParameter(SQL\_PARM\_TITLE, SqlDbType.NVarChar,20),  
                   new SqlParameter(SQL\_PARM\_CONTENT, SqlDbType.NVarChar, 100)\};  
           SqlCommand cmd = new SqlCommand();           // 依次给参数赋值  
           parms\[0\].Value = receive;  
           parms\[1\].Value = send;  
           parms\[2\].Value = title;  
           parms\[3\].Value = content;           //将参数添加到SqlCommand命令中  
           foreach (SqlParameter parm in parms)  
               cmd.Parameters.Add(parm);           //获取数据库的连接字符串  
     using (SqlConnection conn = newSqlConnection(SqlHelper.ConnectionStringLocalTransaction))  
           \{   
               //打开数据库连接，执行命令  
               conn.Open();  
               //设置Sqlcommand命令的属性  
               cmd.Connection = conn;  
               cmd.CommandType = CommandType.Text;  
               cmd.CommandText = SQL\_INSERT\_MESSAGE;  
               //执行添加的SqlCommand命令  
               int val = cmd.ExecuteNonQuery();  
               //清空SqlCommand命令中的参数  
               cmd.Parameters.Clear();

[http://hi.baidu.com/aweibsb/item/e775342a64d231cddcf69ac7][http_hi.baidu.com_aweibsb_item_e775342a64d231cddcf69ac7]

[http_hi.baidu.com_aweibsb_item_e775342a64d231cddcf69ac7]: http://hi.baidu.com/aweibsb/item/e775342a64d231cddcf69ac7