SQLite.NET - Retrieving Data

[Ionix]

I am currently using SQLite.NET Wrapper from http://www.phpguru.org/static/SQLite.NET.html

 

I am currently facing a problem on retrieving the data.

My codes are as below...

SQLiteResultSet tempResult;
ArrayList tempString;

tempResult = sqlite.Execute("SELECT * FROM MARKET;");

tempString = tempResult.Rows;

for(int i=0; i<tempString.Count; i++)
{
Debug.Print((String)tempString[i]);
}

I am trying to typecast the tempString which is an ArrayList to String. But receive this error "Unable to cast object of type 'System.Collections.ArrayList' to type 'System.String'."

 

I am new to C#, please kindly teach me how to convert this?

Thanks.

Edited October 21, 2006 by PlausiblyDamp

[Ionix]

Is this forum thread, as "quiet" as this all the time?

[Nate Bross]

Try using the .ToString() method.

[Ionix]

tried. ToString() will display "'System.Collections.ArrayList".

 

I want the value, not the class.

[Nate Bross]

Just out of curisoty, have you tried

tempString.Item[i].ToString()

[Ionix]

There is no Items[] for ArrayList.!!!

Are you sure about the possibility?

[PlausiblyDamp]

tmpString[i].ToString()

[Ionix]

I tried

 

tempString.ToString() //It will print "System.Collections.ArrayList"

(String)tempString //It will give error "System.InvalidCastException"

 

So what should I do?

 

tempString is an ArrayList and how do I display it's content?

Shouldn't it be tempString?

[PlausiblyDamp]

tempString doesn't contain strings - only just looked at your original post, it looks like it contains an array of DataRow objects. Is that right?

[Ionix]

using SQLite.NET;

[..]

private SQLiteClient db;

[..]
///
/// Load the database on form load. If the database does not
/// exist the client library will create it for us.
///
private void formMain_Load(object sender, System.EventArgs e)
{
    db = new SQLiteClient(�test.db�);
}

///
/// Will execute the SQL command entered on the new database
/// and display the result set. Create the items described,
/// 1 text input for the statement (textSQL), 1 button (buttonExecSQL)
/// and 1 multiline textbox for the output (textOutput)
///
private void buttonExecSQL_Click(object sender, System.EventArgs e)
{
    SQLiteResultSet results;

    try
    {
         results = db.Execute(textSQL.Text);

         textOutput.Text = �Executed. � + results.Rows.Count;
         foreach (ArrayList row in results.Rows)
         {
              textOutput.Text += row[0] + �\r\n�;
         }
    }
    catch (SQLiteException s)
    {
         textOutput.Text += �ERROR: � + s.ErrorCode + � � + s.Message + � in � + s.Source + �\r\n�;
    }
} 

 

This code was copied from http://www.nik.com.au/archives/2005/05/03/using-sqlite-in-net/

 

And what that we are talking here is this portion

foreach (ArrayList row in results.Rows)
         {
              textOutput.Text += row[0] + �\r\n�;
         }

 

If ArrayList here does not contain any String then how does it textOutput.Text?

 

I have to assume that tempString, actually contains some string inside... I mean what else can that be?

[Ionix]

[csharp]

ArrayList row in results.Rows

[/csharp]

 

Doesn't this sentence mean

 

For every results.Rows

ArrayList row = results.Rows

 

?? :confused:

[PlausiblyDamp]

try something like

tmpString[i][0].ToString()

 

and see if that does anything. In their sample the variable row is an array.

[Ionix]

Hi

 

Tried your suggest. Result is...

 

Error 1 Cannot apply indexing with [] to an expression of type 'object'

[Ionix]

Surprisingly base on the example from http://www.nik.com.au/archives/2005/05/03/using-sqlite-in-net/

 

[csharp]

foreach (ArrayList row in results.Rows)

{

textOutput.Text += row[0] + �\r\n�;

}

[/csharp]

 

actually works.

 

but...

 

a for loop in my code cannot work. Anyone can explain this??? it's confusing :confused:

[PlausiblyDamp]

tmpString contains an array but it is returned as an object, you will need to cast the result of tmpString to an Arraylist and then access those elements.

 

Try something like

((ArrayList) tmpString[i])[0].ToString()
//or more explicit
ArrayList tmp = (ArrayList) tmpString[i];
string s = tmp[0].ToString();

[Ionix]

Yes you are right finally it works.

 

So there is a double return of ArrayList... no wander I am unable to convert it to string.

 

Thanks.

 

but the example by Nik, doesn't it only takes in 1 ArrayList row for each loop?

how is it possible for that his example to work that way?

[FZelle]

Just a question, why do you use a Provider that actually ignores ADO.NET and insists

on it's own methods?

 

If you would use http://sourceforge.net/projects/adodotnetsqlite/ for a FW 1.1 prg and

http://sourceforge.net/projects/sqlite-dotnet2/ for a FW 2.0 program you could use

the std. mechanisms in ADO.NET.