SqlParameter帶引數的增刪改查語句,可以防止注入.有時候寫sql語句的時候會根據方法傳進來的引數來判斷sql語句中where條件的引數.

一般方法

DAL層方法

public UserInfo GetAll(UserInfo a)
{
            string strSql = "select id,name,code,password from [tb].[dbo].[User] where 1=1";
            strSql += " and [id][email protected]";
            strSql += " and [name]
 
[email protected]";
            strSql += " and [code][email protected]";
            strSql += " and [password][email protected]";
            SqlParameter[] parameters = { 
					     new SqlParameter("@id", a.id)
                                             new SqlParameter("@name", a.name)
                                             new SqlParameter("@code", a.code), 
                                             new SqlParameter("@password", a.password)
                                 };
            SqlDataReader reader = SqlHelper.ExecuteReader(strSql, parameters);
            UserInfo hc = new UserInfo();
            while(reader.Read())
            {
                hc.id = reader.GetInt32(reader.GetOrdinal("id"));
                hc.name = reader.GetString(reader.GetOrdinal("name"));                
                hc.code = reader.GetString(reader.GetOrdinal("code"));
                hc.password = reader.GetString(reader.GetOrdinal("password"));
            }
            reader.Close();
            return hc;
}
 

方法如下

DAL層方法

public UserInfo GetALL(UserInfo a)
{
            string strSql = "select id,name,code,password from [tb].[dbo].[User] where 1=1";
            if (a.id>0) strSql += " and [id][email protected]";
            if (!string.IsNullOrEmpty(a.name)) strSql += " and [name]
 
[email protected]";
            if (!string.IsNullOrEmpty(a.code)) strSql += " and [code][email protected]";
            if (!string.IsNullOrEmpty(a.password)) strSql += " and [password][email protected]";
            List<SqlParameter> parametertemp = new List<SqlParameter>();
            if (a.id > 0) parametertemp.Add(new SqlParameter("@id", a.id));
            if (!string.IsNullOrEmpty(a.name)) parametertemp.Add(new SqlParameter("@name", a.name));
            if (!string.IsNullOrEmpty(a.code)) parametertemp.Add(new SqlParameter("@code", a.code));
            if (!string.IsNullOrEmpty(a.password)) parametertemp.Add(new SqlParameter("@password", a.password));
            SqlParameter[] parameters = parametertemp.ToArray();//ToArray()方法將 List<T> 的元素複製到新陣列中。
            
            SqlDataReader reader = SqlHelper.ExecuteReader(strSql, parameters);
            UserInfo hc = new UserInfo();
            while (reader.Read())
            {
                hc.id = reader.GetInt32(reader.GetOrdinal("id"));
                hc.name = reader.GetString(reader.GetOrdinal("name"));                
                hc.code = reader.GetString(reader.GetOrdinal("code"));
                hc.password = reader.GetString(reader.GetOrdinal("password"));
            }
            reader.Close();
            return hc;
 }

DBUtility層SqlHelper

public SqlDataReader ExecuteReader(string query, params SqlParameter[] parameters)
        {        
		SqlConnString = GetConnect2();
		SqlConnString.Open();
		SqlCommand SqlCmd = new SqlCommand(); 
		SqlCmd.Connection = SqlConnString; 
		SqlCmd.CommandText = query; 
		//SqlCmd.Parameters.AddRange(parameters);//AddRange()不能傳空引數組
		//params 的意思就是允許傳空引數組
		foreach (SqlParameter item in parameters) 
		{ 
			SqlCmd.Parameters.Add(item); 
		} 
		SqlDataReader dr; 
		try 
		{ 
			dr = SqlCmd.ExecuteReader(CommandBehavior.CloseConnection);
 			return dr; 
		} 
		catch (Exception ee) 
		{ 
			SqlConnString.Close();
 			throw ee; 
		} 
	}