Specific condition against repeated datas...

Question

Hi,

I wrote these codes to save datas (text and image). I need to reject the repeated name (for example: This name already exist). How can I do?

try
{
    byte[] img1 = null;
    FileStream fs1 = new FileStream(imgLoc1, FileMode.Open, FileAccess.Read);
    BinaryReader br1 = new BinaryReader(fs1);
    img1 = br1.ReadBytes((int)fs1.Length);
     string sql = "INSERT INTO intelflex1(ID, name,  age, imagem1)Values(" + txtID.Text + ",'" + txtName.Text  + "','" + txtAge + "','" + "',@img1)";
    if (conn.State != ConnectionState.Open)
        conn.Open();
    comm = new SqlCommand(sql, conn);
    comm.Parameters.Add(new SqlParameter("@img1", img1));
    int x = comm.ExecuteNonQuery();
    conn.Close();
    MessageBox.Show(x.ToString() + "saved successfully!");
}
catch (Exception ex)
{
    conn.Close();
    MessageBox.Show(ex.Message);
}

Sachin Singh · Answer

You can retrieve the count according to name. Method 1. public bool IsExist(string Name) { bool isValid= true ; using (SqlConnection con= new SqlConnection(cs)){ SqlCommand cmd= new SqlCommand( "select count(*) from table where Name=@name" ,con); cmd.Parameters.AddWithValue( "@name" ,Name); con.Open(); int res= Convert.ToInt32(cmd.ExecuteScalar()); if (res>0) { isValid= false ; } return isValid; } } then try { if (IsExist()){ byte[] img1 = null; FileStream fs1 = new FileStream(imgLoc1, FileMode.Open, FileAccess.Read); BinaryReader br1 = new BinaryReader(fs1); img1 = br1.ReadBytes(( int )fs1.Length); string sql = "INSERT INTO intelflex1(ID, name, age, imagem1)Values(" + txtID.Text + ",'" + txtName.Text + "','" + txtAge + "','" + "',@img1)" ; if (conn.State != ConnectionState.Open) conn.Open(); comm = new SqlCommand(sql, conn); comm.Parameters.Add( new SqlParameter( "@img1" , img1)); int x = comm.ExecuteNonQuery(); conn.Close(); MessageBox.Show(x.ToString() + "saved successfully!" ); } else { MessageBox.Show( "Name already Exist" ); } } catch (Exception ex) { conn.Close(); MessageBox.Show(ex.Message); } Method 2. Make the Name column unique key in the Database, so the duplicate name will throw an error that will be caught by your catch block and display.