There are three basic components\steps in creating POL’s application.
The Virtual Table:
This is a submenu item of the main menu item, “Add” which is a graphic object in an image of a table that you Drag & Drop onto the canvas (working space) that creates a table on the canvas which you load into it a database table through a browser connected to the database. This applies to the Novice and Advanced editions of POL which did not require any previous knowledge.
In the case of those users who know how to create database queries, which applies to the Sophisticated and Professional editions of POL, the Virtual Table will be filled with database query results (view).
On top of this table (which contains a database table or query results- view), the user can perform a point & click operation, exactly like in a spreadsheet (like Excel).
Unlike spreadsheets, no need to define a range or copy the formula to all the records.
There is a single formula created by the point & click operation.
This formula works on an unlimited number of records (billions and more).
When you drag & drop the table to the canvas (working space\environment) or select one that is already being dropped, on the left side of the canvas, will appear the properties panel.
This panel represents most of the operations made in the application.
The second stage is to connect a data source to the Virtual Table.
You click on the “Select Data Source” in the Virtual Table panel (above) and the Data Source dialogue box will appear.
You will get from your Database Administrator all the data needed to connect to this database.
Note: You can connect to a remote database server by using the server’s name or its IP address.
You will connect in a much easier way to a local database server you install on your local machine.
After filling in all the data, you will click on the “Add” button and it will be added to the table at the bottom of the Data Source dialogue box.
The next step is to click the check button located on the row added to this table and a login dialogue box will appear, enabling you to put your username and password to connect to this data source.
The next step is to click on this row to select it and click the Select button (above the table).
The Data Source dialogue box will close, the “Select Data Source” button becomes disabled and the “Select DB Table” button that previously was disabled is now enabled. The data source is now connected to the Virtual Table.
You click on the “Select DB Table” button and the database tables will appear in a list.
You select one of the tables and click the “OK” button. There could be thousands of tables in a database, to find your table more easily, there is a field at the top of the list where you can type the first letters of the table name and you will get similar names with proximity to the name. With slight scrolling and you will find the desired name. The data of the database table will fill the Virtual Table.
The next step is to do Point & Click operation as in spreadsheets like Excel and other spreadsheets on top of the Virtual Table to create POL’s Formula.
You can change the default name of the Virtual Table name into a logical arbitrary name of your consideration. This name can be changed before or after creating POL’s formula and will appear in the formula syntax. After creating POL’s formulas, clicking “Enter” will put them in POL’s tab one after another.
POL’s formula contains pointers of different Virtual Tables, which means that you can perform Point & Click operations on different Virtual Tables.
POL’s formula syntax is:
Pointer- Virtual Tables name: [relative column location, relative row location].
Definition- relative means the relative location to the output cell. The relative direction of the column is, to the left of the output cell is negative and to the right is positive. The relative direction of the row is, above the output cell is negative, and below is positive.
Output- on the left side of the equation the syntax is, Virtual Tables name: (output column, general parameters separated by comma).
Example- Cumulative: (2, 3) = Cumulative: [-1, 0] + Cumulative: [0, -1].
You can also see it in POL’s tab and add the formula manually or change the existing one.
Note: Creating a formula can be on data of selected database table or database query (SQL) results.
The Sophisticated and Professional editions of POL can generate database queries (SQL).
The third stage is to create a Data Link. The purpose Data Link is to connect the Virtual Table Data Source to the Data Link and the database query (SQL) it contains.
The Data Link is created automatically in the Novice and Advanced editions of POL, but it is invisible.
The Data Link is created by the users of the Sophisticated and Professional editions of POL, and they can fill it with query syntax (SQL) or generate it automatically using a Visual Query Builder tool.
The table properties panel of the Sophisticated and Professional editions of POL, are different as you can see below.
Note: as you can see, in the Virtual Table panel of the Sophisticated and Professional editions of POL, there are three additional buttons, “Select Data Link”, “Edite SQL Queries” and “Execute SQL” which enable to create POL formula on top of database query result represent in the Virtual Table.
After clicking the “Select Data Source” button and selecting a data source the button will become disabled and the disabled button of the “Select Data Link” will become enabled. When you click on this button the Data Link dialogue box below will appear.
As you can see you can see, the names of the arbitrary names you gave the Virtual Table, and the Data Source already appears in this dialogue box because they are linked automatically. You also give an arbitrary name to the Data Link.
You can type in the database query (SQL) in the editor (above the buttons) or click on the button Visual SQL (on the left above the editor) and open a Visual Query Builder tool that will enable you to visually generate even complex database query (SQL).
You can use the link at the right above the editor “SQL Converter” to convert the SQL syntax to another database.
After you fill in all the details, you click on the “Add” button and it will appear on the table at the bottom. You click on the row, select it, and click the “Select” button. The Data Link dialogue box will be closed, and the query result will appear in the Virtual Table.
At this stage you can perform Point & Click operations on top of this result or several results in different Virtual Tables.
The Roll Back button enables you to reset the database table or query result (note: database term) and start over. The Commit button enables you to save the result into the database.
Whenever you save a file, when loaded, it automatically executes data processing according to the last definition. You can also use the “Run” menu item to determine how it executes data processing when loaded.
