1

I have a database in which I created a table HUGO_BOSS. Its columns are [brand name], [stock quantity], [retail price] and its primery key is [Brand name]. I want to fill my textbox in windows form with the value of stock quantity present in my database. I tried the following code but it gives run-time error

The Connection was not close, the connection state is open. 

if (comboBox2.Text == "HUGO BOSS") { try { OleDbCommand cmd = con.CreateCommand(); cmd.CommandText = "Select [Stock quantity] as stockquantity from HUGO_BOSS WHERE [Brand name]=@name"; cmd.Parameters.AddWithValue("@name", comboBox3.SelectedItem); con.Open(); OleDbDataReader dr = cmd.ExecuteReader(CommandBehavior.SingleResult); if (dr.Read()) { textBox7.Text = dr["stockquantity"].ToString(); } } finally { con.Close(); } }

One more thing, here I will select the primary key by using a combobox3

Improve this question

1 Answer 1

Reset to default
1

It looks you're trying to reuse a database connection that is already open.

You could try testing the connection state before trying to open it:

OleDbCommand cmd = con.CreateCommand(); cmd.CommandText = "Select [Stock quantity] as stockquantity from HUGO_BOSS WHERE [Brand name]=@name"; cmd.Parameters.AddWithValue("@name", comboBox3.SelectedItem); if (con.State == ConnectionState.Closed) { con.Open(); } OleDbDataReader dr = cmd.ExecuteReader(CommandBehavior.SingleResult); if (dr.Read()) { textBox7.Text = dr["stockquantity"].ToString(); }

Alternatively, you could create a new connection each time you need to execute a new command.

Improve this answer
Sign up to request clarification or add additional context in comments.

6 Comments

it gives an error "Multiple-step OLE DB operation generated errors. Check each OLE DB status value, if available. No work was done."
@Dany In your question you say the table name is HUGGO_BOSS, but in the SQL code you're querying table HUGO_BOSS (only one G). Are you sure the SQL query is correct? Also, what type is comboBox3.SelectedItem?
sorry, actually there is a typing mistake in question.The correct spelling is HUGO_BOSS and my combobox3 contains the list of brand name from the database. If a users selects a particular brand name, then my textbox should give its quantity available in the stock.
@Dany If SelectedItem is a string, are you sure that [Brand Name] in a varchar or nvarchar (or char / nchar)? Also, did you specify the database name in your connection string?
yes i specified the database name in connection string. and my brand name is a text. Actually i am using ms access database.
|