SQLite, code only, no TSQLite3Connection

[jbmckim]

I like the DB connectors and I'll use the SQLite connector if need be but I was wondering if there was a "code only" solution.  I'm starting what will likely be a rather large project and I'd like to have my DB access all run through one unit.  This unit will be a worker bee and won't have a UI.  I've looked and maybe my Google skills aren't that sharp but everything I find uses the connectors dropped on a UI.

Thanks.

[valdir.marcos]

Take a look here:
[Solved]How can I create TSQLite3 components in a unit at run time.
http://forum.lazarus.freepascal.org/index.php/topic,30398.msg193409.html#msg193409

[GAN]

I use this unit in my projects. I use ZeosLib but it will serve as a guide.

Code: Pascal  [Select][+][-]

1. unit dbfunctions;
2.  
3. {$mode objfpc}{$H+}
4.  
5. interface
6.  
7. uses
8.     Classes, SysUtils, db, ZConnection, ZDataset, FileUtil
9.     ;
10.  
11. function DB_Exists (sDBase, sTable, sField, sValue: String) : Integer;
12.  
13. implementation
14.  
15.  
16. function DB_Exists (sDBase, sTable, sField, sValue: String) : Integer;    //-1 Database does not exist
17. var                                                                       // 0 Database not Found
18.   ZConn:TZConnection;                                                     // >0 Number of records found
19.   ZQry:TZQuery;
20.   DSource:TDataSource;
21.   iRet:Integer=0;
22. begin
23.   if not(FileExists(sDBase)) then Exit(-1);
24.   ZConn:=TZConnection.Create(nil);
25.   ZQry:=TZQuery.Create(nil);
26.   DSource:=TDataSource.Create(nil);
27.   ZConn.Protocol:='sqlite-3';
28.   ZConn.Database:=sDBase;
29.   ZConn.Connect;
30.   ZQry.Connection:=ZConn;
31.   DSource.DataSet:=ZQry;
32.   DSource.Enabled:=True;
33.   ZQry.SQL.Text:='SELECT '+sField+' FROM '+sTable+' WHERE '+sField+'='+QuotedStr(sValue)+' ;';
34.   ZQry.Open;
35.   iRet:=ZQry.RecordCount;
36.   ZQry.Close;
37.   DSource.Enabled:=False;
38.   ZConn.Disconnect;
39.   FreeAndNil(ZConn);
40.   FreeAndNil(ZQry);
41.   FreeAndNil(DSource);
42.   DB_Exists:=iRet;
43. end;
44.  
45. end.

[Thaddy]

Take a look here:
[Solved]How can I create TSQLite3 components in a unit at run time.
http://forum.lazarus.freepascal.org/index.php/topic,30398.msg193409.html#msg193409

Indeed. Actually I never use the visual component, I always do it like that.

[jbmckim]

Thanks all,

Just to put things (mostly) all in one place:

You do need some things in "uses"

Code: Pascal  [Select][+][-]

1. uses
2.   ..., db, sqldb, sqlite3conn,...;

Then this - I put this in the global vars for the unit:

Code: Pascal  [Select][+][-]

1. var
2.   DBconnection: TSQLite3Connection;  

Then this:

Code: Pascal  [Select][+][-]

1. DBconnection := TSQLite3Connection.Create(nil);  

Mostly putting this here so I can google it later to remind myself

[jbmckim]

And here's a good example of how to use after things are defined:

http://wiki.freepascal.org/TSQLite3Connection