How to Connect to PostgreSQL in Delphi with Devart PgDAC

November 23, 2023

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PostgreSQL is a popular open-source relational database management system (RDBMS) that is widely used for building robust and scalable applications. When developing applications in Delphi, a powerful tool like Devart PgDAC (PostgreSQL Data Access Components) can greatly simplify the process of connecting to and interacting with PostgreSQL databases. In this article, we will guide you through the steps to connect to PostgreSQL in Delphi using Devart PgDAC. We will also compare PgDAC with two similar products from other brands to highlight its advantages.

Installing Devart PgDAC

Devart PgDAC is a set of Delphi components that facilitate seamless connectivity and interaction with PostgreSQL databases in Delphi applications. It is designed to simplify database development and offer advanced features for developers who work with PostgreSQL.

Key Benefits and Features of PgDAC

Direct Mode: PgDAC provides a Direct Mode that allows applications to work with PostgreSQL databases without using the PostgreSQL client library. This results in better performance and reduced dependencies.
Cross-Platform Support: PgDAC supports various versions of Delphi and C++ Builder and is compatible with both 32-bit and 64-bit Windows platforms. This cross-platform support ensures that developers can work on different systems and target platforms.
Visual Query Builder: PgDAC includes a visual query builder, which enables developers to design SQL queries visually without writing complex code. This feature is particularly useful for those who are new to SQL or prefer a more intuitive approach.
Advanced Connection Pooling: PgDAC offers advanced connection pooling, which helps manage database connections efficiently. Connection pooling can significantly enhance application performance, especially in multi-user environments.
Batch Updates: it increases the speed of data operations dramatically. Moreover, in contrast to using Loader, Batch operations can be used not only for insertion, but for modification and deletion as well.
Data Type Mapping: It provides comprehensive data type mapping between PostgreSQL and Delphi data types, ensuring that data is handled correctly when transferring between the database and the application.
SSL Support: PgDAC supports SSL encryption for secure database connections, which is essential for protecting sensitive data in applications.
BLOB Streaming: PgDAC allows developers to work with BLOB (Binary Large Object) data using streaming, which is efficient for handling large binary data such as images or documents.
Unicode Support: PgDAC fully supports Unicode, ensuring compatibility with international character sets and languages.
Automatic Query Execution: Developers can use PgDAC’s automatic query execution feature, simplifying the process of running SQL statements and retrieving results.
Support for PostgreSQL-Specific Features: PgDAC is specifically designed for PostgreSQL, so it provides easy access to PostgreSQL-specific features and functions, including JSONB support, hstore, and more.
Documentation and Support: Devart offers comprehensive documentation, examples, and support resources to assist developers in using PgDAC effectively.

Primary Consumers of PgDAC

Delphi and C++ Builder Developers: PgDAC is primarily targeted at developers who use Embarcadero Delphi or C++ Builder for Windows application development and need to work with PostgreSQL databases. It simplifies database connectivity and management within these development environments.
Business and Enterprise Application Developers: Developers working on business and enterprise-level applications that rely on PostgreSQL as the backend database can benefit from PgDAC’s features and optimizations. These applications often require secure, efficient, and feature-rich database connectivity.
ISVs (Independent Software Vendors): ISVs who build software products for a broad customer base may choose PgDAC to ensure that their applications can connect to PostgreSQL seamlessly. This component helps ISVs maintain database compatibility and performance across various customer environments.
Database Administrators: Database administrators responsible for maintaining PostgreSQL databases may find PgDAC useful for developing custom database management tools and utilities.
Startups and Small Businesses: PgDAC can also be valuable for startups and small businesses looking to build cost-effective, high-performance applications that use PostgreSQL as the database backend.

When you start working with PostgreSQL in Delphi using PgDAC, you need to install the component. Follow these steps to install PgDAC:

Download and Install Devart PgDAC: Visit the Devart website to download the latest version of PgDAC. Once downloaded, run the installer and follow the on-screen instructions to complete the installation.
Launch Delphi: Open Delphi, either an existing project or create a new one.
Adding PgDAC to Your Project:

Click on “Component” in the Delphi menu.
Select “Install Packages.”
Click on “Add” and browse to the location where PgDAC was installed. Usually, it’s under “C:\Program Files (x86)\Devart\PgDAC for RAD Studio XE\xx\Bin.”
Select “PgDACxxx.bpl” (where “xxx” is the version number).
Click “Open” and then “OK.”

Adding PgDAC Components to Your Form:

Open the form you want to work with.
In the “Tool Palette” on the left, you will find a list of PgDAC components. Drag and drop the TPgConnection component onto your form.

Configuring PgDAC Connection:

Double-click on the TPgConnection component to open its properties.
Set the Database property to the name of your PostgreSQL database.
Set the Server property to the hostname or IP address of your PostgreSQL server.
Enter the User and Password properties with the appropriate credentials.
You can also specify other connection properties like Port and Protocol if needed.
Click “OK” to save the settings.

Connecting to PostgreSQL

Now that you have PgDAC installed and configured, let’s see how to connect to a PostgreSQL database:

procedure TForm1.ConnectToPostgreSQL;
begin
  PgConnection1.Connected := True; // Connect to PostgreSQL
  if PgConnection1.Connected then
    ShowMessage('Connected to PostgreSQL!')
  else
    ShowMessage('Failed to connect.');
end;

In the above code, PgConnection1 is the instance of the TPgConnection component you added to your form. By setting the Connected property to True, you establish a connection to the PostgreSQL database.

Working with PgDAC

Once connected, you can perform various database operations using PgDAC, such as querying data, inserting records, updating, and deleting data. Here’s a simple example of executing an SQL query:

procedure TForm1.ExecuteQuery;
var
  Query: TUniQuery;
begin
  Query := TUniQuery.Create(nil);
  try
    Query.Connection := PgConnection1; // Set the connection
    Query.SQL.Text := 'SELECT * FROM your_table';
    Query.Open; // Execute the query
    // Process the query results here
  finally
    Query.Free; // Release resources
  end;
end;

In this code, we create a TUniQuery object, associate it with the PgConnection1, set the SQL query, and open it to fetch the data.

Comparing PgDAC with Similar Product

Now, let’s compare Devart PgDAC with two similar products from other brand to highlight its advantages.

PgDAC vs. FireDAC:

Devart PgDAC is a specialized PostgreSQL component optimized for PostgreSQL database interactions.

While FireDAC is a more generic component that supports multiple database systems, making it less optimized for PostgreSQL-specific features.

PgDAC provides better integration and performance for PostgreSQL as well as lower memory consumption. Unfortunately, a direct comparison between the performance of PgDAC and UniDAC was not carried out, but there is an article where The performance and memory consumption comparison between UniDAC and FireDAC is compared in detail and it is clear that UniDAC has much higher performance and consumes much less memory than FireDAC. And since PgDAC and UnIDAC have a common source code and therefore have the same performance and memory consumption, PgDAC is also much faster than FireDAC and consumes significantly less memory.

Conclusion

Devart PgDAC simplifies the process of connecting to and working with PostgreSQL databases in Delphi. By following the steps outlined in this article, you can quickly set up your development environment and leverage PgDAC’s capabilities for efficient database interactions. When compared to similar products, PgDAC stands out with its PostgreSQL-specific optimizations and advanced features, making it a valuable tool for Delphi developers working with PostgreSQL.

How to Connect to PostgreSQL in Delphi with Devart PgDAC