Some SERIOUS DBase help

[cyprus106]

I've been working with the Data Access components in Builder and toying with Microsoft Access databases and tables and showing the fields, etc... I was just beginning to think I almost had the hang of it and I remember there's the Borland Examples. When I looked at them I got 10x more confused. I seriously need some decent tutorials on this stuff. I've got the database accessed and I can show it on a DBGrid so I don't need to know how to set all of that up, (hint: I don't need that FAQ on setting up a database) what I need to know is more along the lines of examples of using the functions, how I can manipulate data, etc... I've got some problems with programatically moving to a record in the table, doing finds on the record(s), making new records, accessing individual records. All of the little things that I'm sure there's functions for and just when I think I've found them I check the BCB Help file and it's not what I need at all. Or sometimes I just don't know how to use them and can't figure it out. Normally I would just use the help file but it's not really helping me. And their examples, not to mention word phrasing, leave something to be desired.

I hope somebody can help me out here.
Thanks a lot, Cyprus

 

[Frush]

ill send you a program i did for school. theres everything you can do with a database in builder just tell me your email
Query1->Sql->Add("insert into table1(name,firstname)"
Query1->Sql->Add("ValuesName1,FirstName1)"
Query1->Params->Items[0]->AsString = Name1->Text;
Query1->Params->Items[1]->AsString = FirstName1->Text;

thats one way to do request nyway take my prog its open source!

 

[cyprus106]

cyprus@cynoptics.com Cyprus

 

[butthead]

I have had some dificulty with the fieldvalues property
so I tend to stick with the fields [] property.

this puts you on the 10th record.
Table1->RecNo = 10;

Table1->Edit(); // edit field
Table1->Fields->Fields[2]->AsString = s1;
Table1->Fields->Fields[3]->AsBoolean = false;
Table1->Post ();

Table1->Close ();
Table1->ReadOnly = true;
Table1->Open ();

Table1->Active = false;
Table1->EmptyTable ();
Table1->Active = true;

Table2->Close ();
Table2->CreateTable ();
Table2->Open ();

Table2->Append(); //new field
Table2->Fields [0] = Table1->Fields [1];
Table2->Fields [1] = Table1->Fields [3];
Table2->Fields [2] = Table1->Fields [4];
Table2->Post ();

char buff1 [256];
strcpy (buff1, Table1->Fields[4]->AsString.c_str ());

int z = z + Table1->Fields[2]->AsFloat;

{
if (FileExists ("descript.dbf&quot)
{
//Clear the items from design time, default.
DBComboBox1->Items->Clear ();

Table4->Open ();
Table4->First ();
while (!Table4->Eof)
{
DBComboBox1->Items->Add (Table4->Fields[0]->AsString);
Table4->Next ();
}
DBComboBox1->ItemIndex = -1;
Table4->Close ();
}
}

Its easy once you know the secret. and the secret sometimes is interpreting the function parameters.

 

[cyprus106]

OK that helps a lot... Most of that solved most of my problems. But now how do I do something like select an entry in the DB list box (DBBusinessCombo) and make a few of the fields in its row appear under a few of the corresponding Edit Boxes? Cyprus

 

[butthead]

DBEdit boxes have a property called field.
this links the text in this component to the
corresponding field in the selected record.
when you select a record by way of a list box
or other method the text for each field is
displayed. provided you have set up a separate
DBEdit for each field. The Datasource property
also must be set to the datasource of the table.

 

[butthead]

thats "datafield"
oops

tomcruz.net

 

[cyprus106]

I know that much. I can show data in the edit boxes... let me elaborate.

I set up a DBComboBox and it takes all of the data in the first column of my table ('LOCATION NAME'). I tried to set it up so that when a user selects one of the values in the DBCombo, the 3 DBEdit boxes ('LOCATION CITY', 'LOCATION ADDRESS', and 'LOCATION STATE') that I had would change, corresponding to the values in that particular row. When I try to do this the edit boxes to update but the values in them are always the same. They always only show the first row's data.

For example:
if my first row in my table was:
FairCom | 2100 Forum blvd. | Winchestertonfieldville | Missouri
and my second row was:
MyBusiness | 1400 AM Radio | whocaresville | Montana

My DBComboBox would then show both FairCom and MyBusiness. When I select FairCom the right data appears in the edit boxes but when I select MyBusiness the data in the edit boxes stays the FairCom data.

I don't know enough about the database programming yet to know what's going on but I've been stuck on this issue for a week and a half and that was my biggest problem regarding the database stuff.

Thanks, Cyprus

 

[butthead]

I would think that you are iterating through the
database file and grabbing the text from the desired
field and inserting this into the combobox.

Use a TListBox not a TDBComboBox. You dont need the
Database aware stuff for the listbox.
Then you could get the Itemindex of the list box and
do

table1->RecNo = ListBox->ItemIndex;

You may have to adjust the itemindex.
as
table1->RecNo = ListBox->ItemIndex + 1;
or
table1->RecNo = ListBox->ItemIndex - 1;

I Cant remember which offhand.

 

[cyprus106]

ok, I'll say Table1->RecNo = ListBox1->ItemIndex; and the RecNo doesn't change. It's always -1. Help?? Cyprus

 

[butthead]

This works for me;

Questions??

void __fastcall TForm1::FormCreate(TObject *Sender)
{
try
{
if (!FileExists ("test.db&quot)
{
Application->MessageBox(" A new database will now be created.", "New Data File", MB_OK);
Table1->CreateTable ();
Table1->Open ();

Table1->Append ();
Table1->Fields->Fields [0]->AsString = "feild1->record1";
Table1->Fields->Fields [1]->AsString = "feild2->record1";
Table1->Fields->Fields [2]->AsString = "feild3->record1";
Table1->Post ();

Table1->Append ();
Table1->Fields->Fields [0]->AsString = "feild1->record2";
Table1->Fields->Fields [1]->AsString = "feild2->record2";
Table1->Fields->Fields [2]->AsString = "feild3->record2";
Table1->Post ();

Table1->Append ();
Table1->Fields->Fields [0]->AsString = "feild1->record3";
Table1->Fields->Fields [1]->AsString = "feild2->record3";
Table1->Fields->Fields [2]->AsString = "feild3->record3";
Table1->Post ();
}
else
Table1->Open ();
}
catch (...)
{

}

int x = Table1->RecordCount;

for (int y = 0; y < x; y++)
{
Table1->RecNo = y + 1;
ComboBox1->Items->Add (Table1->Fields->Fields [0]->AsString);
}
ComboBox1->ItemIndex = 0;
}

void __fastcall TForm1::ComboBox1Click(TObject *Sender)
{
Table1->RecNo = ComboBox1->ItemIndex + 1;
}