Database SqlParameter insert operation to prevent sql from being injected into the implementation code

  • 2020-06-01 09:36:50
  • OfStack

Example: data is inserted into the database when the Button1 button is clicked.


using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Text;
using System.Data.SqlClient;
using System.Data;
using System.Configuration;
namespace ParaMeter
{
    public partial class Test : System.Web.UI.Page
    {
        private string connectionStr;  // A string that links to a database  
        private SqlConnection conDB;   // Database link 
        private SqlTransaction _trans; // Transaction object 

        protected void Page_Load(object sender, EventArgs e)
        {
            //connectionStr = ConfigurationSettings.AppSettings["constr"];
            connectionStr = "server=10.11.43.189\\SQL2008;database=OA_WEB_DB;uid=sa;pwd=123456";
            conDB = new SqlConnection(connectionStr);
        }
        protected void Button1_Click(object sender, EventArgs e)
        {
            StringBuilder strSql = new StringBuilder();
            strSql.Append("INSERT INTO [OA_WEB_DB].[dbo].[OA_RT_FileType]([FileTypeName],[Deleted])");
            strSql.Append("VALUES(@fileName,@delete)");
            SqlParameter[] parameters = {
                                 new SqlParameter("@fileName", SqlDbType.NVarChar,100),
                                 new SqlParameter("@delete",SqlDbType.Bit),
                             };
            parameters[0].Value = " The file type ";
            parameters[1].Value = false;
          bool IsSucc =   ExecUpdateSql(strSql.ToString(), parameters);
          if (IsSucc)
          {
             Label1.Text =  " Insert the success ";
          }
          else
          {
              Label1.Text = " Insert the failure ";
          }
        }
        ///  perform 1 Bar update statement 
        /// </summary>
        /// <param name="SQLString"> To be executed SQL Statements. </param>
        /// <param name="cmdParms"> Array of execution parameters </param>
        /// <returns> Successfully returns True , failed to return False . </returns>
        private bool ExecUpdateSql(string SQLString, params SqlParameter[] cmdParms)
        {
            using (SqlCommand cmd = new SqlCommand())
            {
                try
                {
                    PrepareCommand(cmd, conDB, _trans, SQLString, cmdParms);
                    int iret = cmd.ExecuteNonQuery();
                    return true;
                }
                catch (System.Data.SqlClient.SqlException e)
                {
                    return false;
                }
            }
        }
        private void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, string cmdText, SqlParameter[] cmdParms)
        {
            if (conn.State != ConnectionState.Open)
                conn.Open();
            cmd.Connection = conn;
            cmd.CommandText = cmdText;
            if (trans != null)
                cmd.Transaction = trans;
            cmd.CommandType = CommandType.Text;//cmdType;
            if (cmdParms != null)
            {
                foreach (SqlParameter parameter in cmdParms)
                {
                    if ((parameter.Direction == ParameterDirection.InputOutput || parameter.Direction == ParameterDirection.Input) &&
                        (parameter.Value == null))
                    {
                        parameter.Value = DBNull.Value;
                    }
                    cmd.Parameters.Add(parameter);
                }
            }
        }
    }
}


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