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 Berlin | Samples and then navigate to:
Object Pascal\Database\FireDAC\Samples\DBMS Specific\PostgreSQL\Arrays
- Subversion Repository:
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