I have error while I'm trying to save winforms textboxes values into a connected MS access database

Question

I have created winform project and bound MS Access database to it, I have created dataGridView which its dataSource is from MS Acess database.

I also have created 3 textboxes as to carry data inputs and created "add button" to save textboxes values into MS Access database and show these data in the dataGridView.

This is the "add button" code:

> private void button1_Click(object sender, EventArgs e)  
>     {  
>         string firstName = textBox1.Text;  
>         string secondName = textBox2.Text;  
>         int age =Convert.ToInt32(textBox3.Text);  
>         int ID = 0;  
>         ID += 1;  
>   
>         theDatabase1DataSet.Table1.Rows.Add(ID, firstName,   
>           secondName, age);  
>         textBox1.Text = "";  
>         textBox2.Text = "";  
>         textBox3.Text = "";  
>         MessageBox.Show("Inputs have been saved");  
>     }  
  
I have created winform project and bound MS Access database to it, I have created dataGridView which its dataSource is from MS Acess database.  
  
![enter image description here][2]  
  
I also have created 3 textboxes as to carry data inputs and created "add button" to save textboxes values into MS Access database and show these data in the dataGridView.  
  
This is the "add button" code:  
  
private void button1_Click(object sender, EventArgs e)  
    {  
        string firstName = textBox1.Text;  
        string secondName = textBox2.Text;  
        int age =Convert.ToInt32(textBox3.Text);  
        int ID = 0;  
        ID += 1;  
  
        theDatabase1DataSet.Table1.Rows.Add(ID, firstName,   
          secondName, age);  
        textBox1.Text = "";  
        textBox2.Text = "";  
        textBox3.Text = "";  
        MessageBox.Show("Inputs have been saved");  
    }  

When I enter text in the textboxes and click on "add button"

This error message appears " System.ArgumentException: 'Input string was not in a correct format.Couldn't store in age Column. Expected type is Int32.'"

Answer 1

Seeing

System.Data.ConstraintExccption: ‘Column 'ID' is constrained to be unique. Value T is already present.’

Means you need to determine if a record exists with the value you are attempting to add with so check for it first like

SELECT 1 FROM YOUR_TABLE_NAME WHERE ID = (the value to use and should be done with a parameter)

Use ExecuteScalar() if it's null then insert the record else donot as this will be the same constraint violation you have now.