FireDAC.PostgreSQL Arrays Sample
This sample demonstrates how to use the TFDParam.ArrayType property to send arrays to a PostgreSQL database server using FireDAC.
Contents
Location
You can find the Arrays project at:
- Start | Programs | Embarcadero RAD Studio Athens | Samples and then navigate to:
Object Pascal\Database\FireDAC\Samples\DBMS Specific\PostgreSQL\Arrays
- Subversion Repository:
- You can find Delphi code samples in GitHub Repositories. Search by name into the samples repositories according to your RAD Studio version.
Description
The Arrays sample shows you how to use the TFDParam.ArrayType property to send arrays to a PostgreSQL database server. To this end, the ArrayType property is set to atTable
.
How to Use the Sample
- Navigate to the location given above and open
PGArrays.dproj
. - Press F9 or choose Run > Run.
Files
File in Delphi | Contains |
---|---|
|
The project itself. |
|
The main form. |
Implementation
Before running the sample, the main components are configured at design time using the Object Inspector as follows:
- A TFDConnection object named FDConnection1. This is the FireDAC connection object that the sample uses to connect to a DBMS. The sample sets the ConnectionDefName property to
PG_Demo
.
- A TFDQuery object named FDQuery1. This component implements a dataset capable of executing SQL queries. The sample sets its Connection property to
FDConnection1
to specify the FireDAC connection object.
- A TDataSource object named DataSource1. This component provides an interface between a dataset component and data-aware controls on a form. In this sample, it is used to provide communication between the dataset and the grid where the dataset is displayed. To this end, the sample sets the following properties:
- The DataSet property of DataSource is set to
FDQuery1
. - The DataSource property of DBGrid1 is set to
DataSource1
.
- The DataSet property of DataSource is set to
When you run the application, you see a grid, a combo box and two buttons labeled as PG Read and PG Write. The purpose of these components in this sample is the following:
- TDBGrid - This sample uses the grid to display the arrays.
- TComboBox - Use the combo box to choose whether to define the array as
ftArray
orftDataSet
. - TButtons - Both buttons have an OnClick event to do the following:
- PG Read:
- Uses the Open method to read the arrays from the database server. The sample displays the arrays on the grid.
- PG Write:
- Press this button to send arrays to a database server. When you press this button, the sample takes the following steps:
- Uses the Text property of SQL to set the SQL command that FDQuery1 will execute.
- Sets the TFDParam.DataTypeName to specify the field name as
<TableName>.<FieldName>
. - Sets the TFDParam.ArrayType property to
atTable
.- Note: If you set it to
atArray
it does not work.
- Note: If you set it to
- Sets the array size with the TFDParam.ArraySize property.
- Sets the arrays using the AsStrings property:
- Sends the arrays to the database server by executing the SQL command specified in the first step.
Uses
- FireDAC.Comp.Client.TFDConnection
- FireDAC.Comp.Client.TFDQuery
- Data.DB.TDataSource
- Vcl.DBGrids.TDBGrid
- FMX.StdCtrls.TButton
- Vcl.StdCtrls.TComboBox
See Also
Samples
- FireDAC InterBase Arrays sample
- FireDAC PostgreSQL Ranges sample