how to make search of a string in a data base in c#

Question

This is the code that is used to make the search

 private void button1_Click(object sender, EventArgs e)
    {
        string connectionString = Tyre.Properties         


        

Answer 1

First off, your code is wide open to SQL Injection. You allow the user to insert any data he wants including

; DROP TABLE table1

To fix the immediate issue surround the item to be matched with single quotes and % signs:

"SELECT * FROM table1 where Nom like '%" + textBox1.Text + "%'"

However, you absolutely should look into using a parameterized query.