Articles InterBase mit Arrays und FireDAC (Interbase with Arrays and FireDAC) by Matthias Eißing (German article)

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InterBase mit Arrays und FireDAC (Interbase with Arrays and FireDAC)

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Matthias Eißing
14/4/2020

InterBase has been offering the possibility to use arrays since time immemorial.

What are arrays?
Arrays are one or more dimensional data stores of the same type within a column. These can be used with InterBase with all standard data types, except for BLOBs.

When should you use it / when not?
Arrays can be defined quite easily . But you should note when you should use them and when you should be better:

• The data of the array are of the same type
• The data of the array are used as a logical (data belong together) and physical (storage in one column; under common transaction control) unit.

Advantages result from the reduced load due to the transaction control: You can simply read and save one slide of data (one / multi-dimensional) in an array within a single transaction. The latter may result in significant performance advantages

Arrays are created as extensions of CREATE TABLEor CREATE DOMAIN:

CREATE TABLE TBL_ARRAY
(
ID INTEGER,
TICTACTOE BOOLEAN[1:3, 1:3]
);

Here a Tic Tac Toe field is defined in a column.

With / with FireDAC it looks like this in the Delphi IDE:

(View from the data explorer)

Within an application. (Normal DBGrid and 3x3 DBCheckBox)

It should be noted that first the rows / rows and then the columns / columns in the array are run through. Fortran, for example, expects a column / row order .

As of Berlin 10.1, the DBGrid also correctly displays an array!

Program access to the array elements
The array elements can be accessed directly via the 0-based elements. Alternating here:

Tbl_arrayTable.Edit;
Tbl_arrayTable.FieldByName('TICTACTOE[0]').Value := NOT Tbl_arrayTable.FieldByName('TICTACTOE[0]').AsBoolean;

What to pay attention to?
Unfortunately, the InterBase Console cannot display arrays:

My colleague Stephen Ball also made a nice video about it (in English)

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