ADO.Net connection in C#

Question

Hi Friends After making the ADO.Net connection when i am trying to fetch the s_name value based on the input from textbox using below query. I am getting object reference null error. Can anybody identify what actually is the flaw in the below code string @searchValue = txtStudentName.Text; string sql = SELECT * FROM Student_Detail where s_name=@searchValue; No record is coming in sql object. SqlCommand cmd = new SqlCommand(sql connection);

Rojalin Sahoo · Answer

As your s_name is a string value(varchar/nvarchar for DB) there must be single quotes for that search value. So change your command like this string sql = SELECT * FROM Student_Detail where s_name='  + @searchValue +  ' ;

Sumit Dwivedi · Answer

Hi Ravi I wrote this code:- string connectionString = Data Source=.;Initial Catalog=Student;Integrated Security=True; string sql = SELECT * FROM Student_Detail where s_name= + @searchValue; SqlConnection connection = new SqlConnection(connectionString); SqlCommand cmd = new SqlCommand(sql connection); //conne.Open(); connection.Open(); SqlDataReader dr = cmd.ExecuteReader(); DataTable dt = new DataTable(); dt.Load(dr); //dataDataSource = dt; //GridView1.DataBind(); dataGridView1.DataSource = dt; It is throwing error as invalid column name 'sumit' when i am entering sumit as my search character in textbox. The error is coming just after this line:- SqlDataReader dr = cmd.ExecuteReader();

Krishna Rajput Singh · Answer

Hello Sumit Dwivedi Thanks for writing i hope below links helpful for you...:) https://msdn.microsoft.com/en-us/library/dw70f090(v=vs.110).aspx http://csharp.net-informations.com/data-providers/csharp-sql-server-connection.htm http://www.codeproject.com/Articles/8477/Using-ADO-NET-for-beginners Special Thanks http://www.c-sharpcorner.com/

Upendra Pratap Shahi · Answer

use this- string sql = SELECT * FROM Student_Detail where s_name=+@searchValue;

Ravi Patel · Answer

Hi Sumit  try this string @searchValue = txtStudentName.Text; string sql = SELECT * FROM Student_Detail where s_name=@searchValue; SqlDataReader myReader = null; SqlCommand cmd = new SqlCommand(sql connection); cmd.Parameters.Add(searchValue); myReader = cmd.ExecuteReader(); while(myReader.Read()) { var id =myReader[Column1].ToString(); }