DataBind Controls to SQL Server Data in Delphi

The CData ODBC driver for SQL Server supports the ODBC standard to enable integration of live SQL Server data with visual form designers and other rapid development tools in Delphi. The ODBC driver simplifies data access strategies for applications that share a single codebase like Delphi by providing a single API for database development. This article shows how to how to connect to SQL Server data and query data from a simple visual component library (VCL) application, as well as from Delphi code.

Create a Connection to SQL Server Data

If you have not already, first specify connection properties in an ODBC DSN (data source name). This is the last step of the driver installation. You can use the Microsoft ODBC Data Source Administrator to create and configure ODBC DSNs.

Connecting to Microsoft SQL Server

Connect to Microsoft SQL Server using the following properties:

• Server: The name of the server running SQL Server.
• User: The username provided for authentication with SQL Server.
• Password: The password associated with the authenticating user.
• Database: The name of the SQL Server database.

Connecting to Azure SQL Server and Azure Data Warehouse

You can authenticate to Azure SQL Server or Azure Data Warehouse by setting the following connection properties:

• Server: The server running Azure. You can find this by logging into the Azure portal and navigating to "SQL databases" (or "SQL data warehouses") -> "Select your database" -> "Overview" -> "Server name."
• User: The name of the user authenticating to Azure.
• Password: The password associated with the authenticating user.
• Database: The name of the database, as seen in the Azure portal on the SQL databases (or SQL warehouses) page.

SSH Connectivity for SQL Server

You can use SSH (Secure Shell) to authenticate with SQL Server, whether the instance is hosted on-premises or in supported cloud environments. SSH authentication ensures that access is encrypted (as compared to direct network connections).

SSH Connections to SQL Server in Password Auth Mode

To connect to SQL Server via SSH in Password Auth mode, set the following connection properties:

• User: SQL Server User name
• Password: SQL Server Password
• Database: SQL Server database name
• Server: SQL Server Server name
• Port: SQL Server port number like 3306
• UserSSH: "true"
• SSHAuthMode: "Password"
• SSHPort: SSH Port number
• SSHServer: SSH Server name
• SSHUser: SSH User name
• SSHPassword: SSH Password

SSH Connections to SQL Server in Public Key Auth Mode

To connect to SQL Server via SSH in Password Auth mode, set the following connection properties:

• User: SQL Server User name
• Password: SQL Server Password
• Database: SQL Server database name
• Server: SQL Server Server name
• Port: SQL Server port number like 3306
• UserSSH: "true"
• SSHAuthMode: "Public_Key"
• SSHPort: SSH Port number
• SSHServer: SSH Server name
• SSHUser: SSH User name
• SSHClientCret: the path for the public key certificate file

You can then follow the steps below to use the Data Explorer to create a FireDAC connection to SQL Server data.

1. In a new VCL Forms application, expand the FireDAC node in the Data Explorer.
2. Right-click the ODBC Data Source node in the Data Explorer.
3. Click Add New Connection.
4. Enter a name for the connection.
5. In the FireDAC Connection Editor that appears, set the DataSource property to the name of the ODBC DSN for SQL Server.

👁 A FireDAC connection to the ODBC data source. (Salesforce is shown.)

Create VCL Applications with Connectivity to SQL Server Data

Follow the procedure below to start executing queries to SQL Server data from a simple VCL application that displays the results of a query in a grid.

1. Drop a TFDConnection component onto the form and set the following properties:

   • ConnectionDefName: Select the FireDAC connection to SQL Server data.
   • Connected: Select True from the menu and, in the dialog that appears, enter your credentials.

2. Drop a TFDQuery component onto the form and set the properties below:

   • Connection: Set this property to the TFDConnection component, if this component is not already specified.

   • SQL: Click the button in the SQL property and enter a query. For example:

     SELECT ShipName, Freight FROM Orders
     

   • Active: Set this property to true.

3. Drop a TDataSource component onto the form and set the following property:

   • DataSet: In the menu for this property, select the name of the TFDQuery component.

4. Drop a TDBGrid control onto the form and set the following property:

   • DataSource: Select the name of the TDataSource.
5. Drop a TFDGUIxWaitCursor onto the form — this is required to avoid a run-time error.

👁 Components in FireDAC used to databind an editable grid to the data source. (Salesforce is shown.)

Execute Commands to SQL Server with FireDAC Components

You can use the TFDConnection and TFQuery components to execute queries to SQL Server data. This section provides SQL Server data-specific examples of executing queries with the TFQuery component.

Connect to SQL Server Data

To connect to the data source, set the Connected property of the TFDConnection component to true. You can set the same properties from code:

FDConnection1.ConnectionDefName := 'mysql';
FDConnection1.Connected := true;

Create Parameterized Queries

Parameterized resources can improve performance: Preparing statements is costly in system resources and time. The connection must be active and open while a statement is prepared. By default, FireDAC prepares the query to avoid recompiling the same query over and over. To disable statement preparation, set ResourceOptions.DirectExecute to True; for example, when you need to execute a query only once.

Execute a Query

To execute a query that returns a result set, such as a select query, use the Open method. The Open method executes the query, returns the result set, and opens it. The Open method will return an error if the query does not produce a result set.

FDQuery1.Open('select * from Orders where ShipCountry = :ShipCountry',['USA']);

To execute a query that does not return a result set, such as a delete, use the ExecSQL method. The ExecSQL method will return an error if the query returns a result set. To retrieve the count of affected rows, use the TFD.RowsAffected property.

FDQuery1.ExecSQL('delete from Orders where Id= :myId',['x12345']);
i := FDQuery1.RowsAffected;

Related Articles

Below you can find other articles for using the CData ODBC Driver with RAD Studio, Delphi, and C++ Builder.

• DataBind Controls to SQL Server Data in C++Builder
• Viewing SQL Server Data in RAD Studio Data Explorer
• Build a Simple VCL Application for SQL Server Data