* Load extension demo by Silvio Clecio

git-svn-id: trunk@40610 -

.gitattributes

@@ -2098,8 +2098,10 @@ packages/fcl-db/examples/loadlibdemo.lpi svneol=native#text/plain
 packages/fcl-db/examples/loadlibdemo.pp svneol=native#text/plain
 packages/fcl-db/examples/logsqldemo.lpi svneol=native#text/plain
 packages/fcl-db/examples/logsqldemo.pas svneol=native#text/plain
+packages/fcl-db/examples/myext.pp svneol=native#text/plain
 packages/fcl-db/examples/pqeventstest.pp svneol=native#text/plain
 packages/fcl-db/examples/showcsv.pp svneol=native#text/plain
+packages/fcl-db/examples/sqlite3extdemo.pp svneol=native#text/plain
 packages/fcl-db/examples/sqlite3loadlib.lpr svneol=native#text/plain
 packages/fcl-db/examples/sqlparser.pp svneol=native#text/plain
 packages/fcl-db/examples/tsamytable.pp svneol=native#text/plain

packages/fcl-db/examples/myext.pp

@@ -0,0 +1,49 @@
+library myext;
+
+{$mode objfpc}{$h+}
+
+uses
+  sysutils,
+  ctypes,
+  sqlite3,
+  sqlite3ext;
+
+procedure mysum(ctx: psqlite3_context; n: cint; v: ppsqlite3_value); cdecl;
+var
+  a, b, r: cint;
+begin
+  a := sqlite3_value_int(v[0]);
+  b := sqlite3_value_int(v[1]);
+  r := a + b;
+  sqlite3_result_int(ctx, r);
+end;
+
+procedure myconcat(ctx: psqlite3_context; n: cint; v: ppsqlite3_value); cdecl;
+var
+  a, b, r: ansistring;
+begin
+  a := sqlite3_value_text(v[0]);
+  b := sqlite3_value_text(v[1]);
+  r := a + b;
+  sqlite3_result_text(ctx, @r[1], length(r), nil);
+end;
+
+function sqlite3_extension_init(db: Psqlite3; pzErrMsg: Ppcchar;
+  const pApi: Psqlite3_api_routines): cint; cdecl; export;
+var
+  rc: cint;
+begin
+  SQLITE_EXTENSION_INIT2(pApi);
+  rc := sqlite3_create_function(db, 'mysum', 2, SQLITE_UTF8, nil,
+    @mysum, nil, nil);
+  if rc = SQLITE_OK then
+    Result := sqlite3_create_function(db, 'myconcat', 2, SQLITE_UTF8, nil,
+      @myconcat, nil, nil);
+  Result := rc;
+end;
+
+exports
+  sqlite3_extension_init;
+
+begin
+end.

packages/fcl-db/examples/sqlite3extdemo.pp

@@ -0,0 +1,40 @@
+program test;
+
+{$mode objfpc}{$H+}
+
+uses
+  sysutils,
+  sqlite3conn,
+  sqlite3ext,
+  sqldb;
+
+const
+  SharedPrefix = {$ifdef mswindows}''{$else}'lib'{$endif};
+
+var
+  con: TSQLite3Connection;
+  trans: TSQLTransaction;
+  q: TSQLQuery;
+begin
+  con := TSQLite3Connection.Create(nil);
+  trans := TSQLTransaction.Create(con);
+  q := TSQLQuery.Create(con);
+  try
+    trans.DataBase := con;
+    q.DataBase := con;
+    q.Transaction := trans;
+    con.DatabaseName := 'test.sqlite3';
+    con.Open;
+    con.LoadExtension(ExtractFilePath(ParamStr(0)) +
+      SharedPrefix + 'myext.' + SharedSuffix);
+    q.SQL.Text := 'SELECT mysum(2, 3);';
+    q.Open;
+    WriteLn('MYSUM: ', q.Fields[0].AsInteger); // prints "MYSUM: 5"
+    q.Close;
+    q.SQL.Text := 'SELECT myconcat(''abc'', ''123'');';
+    q.Open;
+    WriteLn('MYCONCAT: ', q.Fields[0].AsString); // prints "MYCONCAT: abc123"
+  finally
+    con.Free;
+  end;
+end.