How to Insert/Edit Rows in Firebird Dataset in Delphi using FIBPLUS Components?

How to Insert/Edit Rows in Firebird Dataset in Delphi using FIBPLUS Components?

You can insert a row and edit an existing row in firebird dataset in Delphi. I will use FIBPLUS dataset component in Delphi XE4. Just use Insert and Edit procedures for this purpose. First of all create a dataset of type TpFIBDataset. Lets have a look at this very simple example.

var

dsMyFirebirdDataset : TpFIBDataset;

Insert a row in a dataset

with dsMyFirebirdDataset do

begin

Insert;

dsMyFirebirdDatasetID.AsInteger := 101;

dsMyFirebirdDatasetDESC.AsString := 'Hello';

Post;

end;

You can also use FieldByName like following:

with dsMyFirebirdDataset do

begin

Insert;

FieldByName('ID').AsInteger := 101;

FieldByName('DESC').AsString := 'Hello';

Post;

end;

Similarly, you can edit a record/row in the dataset like following:

Edit a row in a dataset

With dsMyFirebirdDataset do

begin

Edit;

dsHdwPriceGroupDESC.AsString := 'Hello World';

Post;

end;

or

With dsMyFirebirdDataset do

begin

Edit;

FieldByName('DESC').AsString := 'Hello World';

Post;

end;

How to populate data into dataset from Firebird database in Delphi using FIBPLUS components?

How to populate data into dataset from Firebird database in Delphi using FIBPLUS components?

I am using Firebird 2.5.2 database and Delphi XE4. I will be using FIBPlus TpFIBDatabase and TpFIBDataset components to populate data from Firebird database to dataset in Delphi XE4. For this, you have to drag TpFIBDatabase and TpFIBDataset components into your Delphi Form from the Tool Palette. Set various properties of TpFIBDatabase component like DBName, Username, Password and LibraryName to connect to Firebird database. I have written a complete tutorial on this. After successfully creating the database connection, set following properties of TpFIBDataset component:

Database: Provide the name of database component (TpFIBDatabase) in Database property. In my case, I have created dbMyDatabase component in my previous article.

SQLs: Write the query which you want to run. In my case, I am running following query:

SELECT ID, NAME FROM MY_FIREBIRD_TABLE WHERE ID = :ID AND NAME = :NAME;

Now, populate your dataset like this:

var

dsMyDataSet : TpFIBDataSet;

with dsMyDataSet do

begin

  Active := False;

  Params.ParamByName('ID').AsInteger := 1000;

  Params.ParamByName('NAME').AsString := 'Naresh';

  Active := True;

  RecordCount;

end;

Note: You can also set Database and SQLs properties in pas file as following:

with dsMyDataSet do

begin

  Active := False;

  Database := dbMyDatabase;

  SQLs.SelectSQL.Text := 'SELECT ID, NAME FROM MY_FIREBIRD_TABLE WHERE ID =:ID                                               AND NAME = :NAME;';

  Params.ParamByName('ID').AsInteger := 1000;

  Params.ParamByName('NAME').AsString := 'Naresh';

  Active := True;

  RecordCount;

end;

How to create database connection with Firebird in Delphi using FIBPLUS components?

How to create database connection with Firebird in Delphi using FIBPLUS components?

I am using Firebird 2.5.2 with Delphi XE4. I will show you how to create a database connection with Firebird database in Delphi XE4 using FIBPLUS component? Just go into the Tool Palette and search for TpFIBDatabase component under FIBPLUS. Drag it into the form and name it. I have given "dbMyDatabase" name to TpFIBDatabase database component. If you see your pas file, a declaration for TpFIBDatabase will look like this:

var
dbMyDatabase: TpFIBDatabase;

Now create a function "ConnectToDatabae" with return type boolean. This function will return true if Firebird database connection is established successfully otherwise false.

function TMyForm.ConnectToDatabase : boolean; 
begin
  result := False;
  try
    try
      with dbMyDatabase do
     begin
        DBName := 'C:\MyProject\MyDB.FDB';
ConnectParams.UserName := 'SYSDBA';
ConnectParams.Password := 'masterkey';
LibraryName := 'C:\Program Files(86)\Firebird\Firebird_2_5\bin\fbclient.dll'; 
Connected := True;
     end;
     result := True;
    except
`     result := False;
end;
  finally
    dbMyDatabase.Connected := False;
  end;
end;

In the above function, I have set different properties of TpFIBDatabase component like DBName, Username, Password, LibraryName etc as following:

DBName := 'C:\MyProject\MyDB.FDB'; //MyDB is the firebird database name
ConnectParams.UserName := 'SYSDBA'; //Default username of firebird database
ConnectParams.Password := 'masterkey'; //Default password of firebird database
LibraryName := 'C:\Program Files(86)\Firebird\Firebird_2_5\bin\fbclient.dll'; //Default library path of firebird database

Note: You can set all these properties at design time in your dfm file. But I would recommend to write all these settings in your pas file.

After setting the above properties, I have set connected property to true. If Firebird database connection is established successfully, above function will return true otherwise false. Finally, I am disconnecting the database.

How to use TpFIBDataSet, TpFIBQuery and TpFIBTransaction FIBPlus components to connect with Firebird / Interebase database in Delphi XE4?

How to use TpFIBDataSet, TpFIBQuery and TpFIBTransaction FIBPlus components to connect with Firebird / Interebase database in Delphi XE4?

Following is the basic article on Firebird / Interbase database connectivity in Delphi XE4 using FIBPlus database components like TpFIBDataSet, TpFIBQuery and TpFIBTransaction. I will explain all these FIBPlus database components in detail. I have written a small article on TpFIBDatabase before this article. Please go through that before reading this one. Read FIBPlus TpFIBDatabase...

FIBPlus TpFIBQuery Component

An application works with a database by issuing SQL instructions. They are used to get and modify data\metadata. FIBPlus has a special TpFIBQuery component responsible for SQL operator execution. This robust, light and powerful component can perform any actions with the database. 

TpFIBQuery is very easy-to-use: just set the TpFIBDatabase component, fill in the SQL property and call any ExecQuery method (ExecQueryWP, ExecQueryWPS). 

NOTE: The tpFIBQuery is not a TDataset descendant, so it does not act in exactly the same way or exhibit the same methods / properties as you would expect to find in a dataset. 

The example below will show how to create TpFIBQuery dynamically at run-time and thus get data about clients.

 var sql: TpFIBQuery;

 sql := TpFIBQuery.Create(nil);

 with sql do

 try

 Database := db;

 Transaction := db.DefaultTransaction;

 SQL.Text := 'select first_name, last_name from customer';

 ExecQuery;

 while not Eof do begin

 Memo1.Lines.Add(

 FldByName['FIRST_NAME'].AsString+' '+

 FldByName['LASTST_NAME'].AsString);

 Next; end;

 sql.Close;

 finally

 sql.Free;

 end;

FIBPlus TpFIBDataSet component

The TpFIBDataSet component is responsible for work with datasets. It is based on the TpFIBQuery component and helps to cache selection results. TpFIBDataSet is a TDataSet descendant so it supports all TDataSet properties, events and methods.

TpFIBDataSet enables you to select, insert, update and delete data. All these operations are executed by TpFIBQuery components in TpFIBDataSet. 

To select data you set the SelectSQL property. It’s similar to setting the SQL property of the QSelect component (TpFIBQuery type). Define the InsertSQL.Text property to insert data, UpdateSQL.Text to update, DeleteSQL.Text to delete and RefreshSQL.Text to refresh the data. 

Here is a demo database employee.gdb (or .fdb for Firebird) to show how to write Select SQL and get a list of all employees. I will write all queries in InsertSQL, UpdateSQL, etc.

with pFIBDataSet1 do begin

 if Active then Close;

 SelectSQL.Text := 'select CUST_NO, CUSTOMER, CONTACT_FIRST, CONTACT_LAST from CUSTOMER';

 InsertSQL.Text := 'insert into CUSTOMER(CUST_NO, CUSTOMER, CONTACT_FIRST,                                           CONTACT_LAST )' + 

                              ' values (:CUST_NO, :CUSTOMER, :CONTACT_FIRST, :CONTACT_LAST)';

 UpdateSQL.Text := 'update CUSTOMER set CUSTOMER = :CUSTOMER, '+

                   'CONTACT_FIRST = :CONTACT_FIRST, CONTACT_LAST = :CONTACT_LAST '+

                   'where CUST_NO = :CUST_NO';

 DeleteSQL.Text := 'delete from CUSTOMER where CUST_NO = :CUST_NO';

 RefreshSQL.Text := 'select CUST_NO, CUSTOMER, CONTACT_FIRST, CONTACT_LAST '                                       + 'from CUSTOMER where CUST_NO = :CUST_NO';

 Open;

end;

To open TpFIBDataSet either execute Open/OpenWP methods or set the Active property to True. To close TpFIBDataSet call the Close method

FIBPlus TpFIBTransaction component

A transaction is an operation of database transfer from one consistent state to another. All operations with the dataset (data/metadata changes) are done in the context of a transaction. To understand special FIBPlus features completely you need to know about InterBase / FIBPlus transactions. 

All the changes done in the transaction can be either committed (in case there are no errors) by Commit or rolled back (Rollback). Besides these basic methods TpFIBTransaction has their context saving analogues: CommitRetaining and RollbackRetaining, i.e. on the client side, these will not close a TpFibQuery or TpFibDataset.

To start the transaction you should call the StartTransaction method or set the Active property to True. To commit the transaction call Commit/CommitRetaing, to roll it back - Rollback/RollbackRetaining. 

TpFIBQuery and TpFIBDataSet components have some properties which help to control transactions automatically. In particular they are: the TpFIBDataSet.AutoCommit property; the poStartTransaction parameter in TpFIBDataSet.Options; qoStartTransaction and qoCommitTransaction in TpFIBQuery.Options.

TpFIBTransaction has three basic transaction types: 

tpbDefault, 

tpbReadCommited, 

tpbRepeatableRead. 

At design time you can also create special types of your own in the TpFIBTransaction editor and use them as internal ones. Set the transaction type to set its 

parameters:

TpbDefault – parameters must be set in TRParams

tbpReadCommited – shows the ReadCommited isolation level

tbpRepeatableRead – shows the RepeatableRead isolation level 

How to use TpFIBDatabase FIBPlus Component to connect with Firebird database in Delphi XE4?

How to use TpFIBDatabase FIBPlus Component to connect with Firebird database in Delphi XE4?

TpFIBDatabase component is used to make database connectivity with Firebird database in Delphi. For using TpFIBDatabase component, you should have FIBPlus and Firebird installed on your system. I am using Delphi XE4, Firebird 2.5.2 and FIBPlus 7.5 to make database connection.

Connection parameters are typical for InterBase/Firebird server:

1) path to a database file;

2) user name and password;

3) user role;

4) charset;

5) dialect;

6) client library (gds32.dll for InterBase and fbclient.dll for Firebird).

To connect to a database you should call the Open method or set the Connected property to True. It’s also possible to use this code to connect to a database:

function Login(DataBase: TpFIBDatabase; dbpath, uname, upass, urole: string): Boolean;

begin

 if DataBase.Connected then DataBase.Connected := False; 

 with FDataBase.ConnectParams do begin

   UserName := uname;

   Password := upass;

   RoleName := urole;

 end;

 DataBase.DBName := dbpath;

 try DataBase.Connected := True;

 except

   on e: Exception do

   ShowMessage(e.Message);

 end;

 Result := DataBase.Connected;

end;

To close the connection either call the Close method or set the Connected property to False. 

You can also close all datasets and connected transactions at once:

procedure Logout(DataBase: TpFIBDatabase);

var i: Integer;

begin

  if not DataBase.Connected then

  Exit;

  for i := 0 to DataBase.TransactionCount - 1 do

    if TpFIBTransaction(DataBase.Transactions[i]).InTransaction then 

      TpFIBTransaction(DataBase.Transactions[i]).Rollback

 DataBase.CloseDataSets;

 DataBase.Close;

end;