Dynamic data import / export

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Merging CSV and Excel data using an SQLite database

In this example we demonstrate how data from a CSV text file and an Excel list can be merged into a large export text file in flat file report format.

It is often the case that data derive from various (data) sources and need to be merged into a consolidated list (export file). For simplicity our example only merges two sources here. However, applying this method you can combine any number of sources and as much data as you wish.

For each source we require a separate FlowHeater Definition in order to first store the data temporarily in an SQLite database. Perhaps you are wondering why SQLite? Theoretically almost any database would suffice, but with SQLite we have the advantage that there is no need for supplementary database tools. FlowHeater is all we need to manipulate data with an SQLite database.

Import CSV text file into the SQLite database

We start by importing the CSV file into the SQLite database. First create a new FlowHeater Definition and choose the TextFile Adapter for the READ side and the SQLite Adapter for the WRITE side. Configure the READ side Adapter to select the CSV text file "text-data.csv" for input and close the Configurator for the CSV file.

Now position your mouse cursor in Designer over the SQLite Adapter on the WRITE side (do not open the Configurator yet) and select with a right mouse click "Adopt the READ fields" option.

Now open the Configurator for the SQLite Adapter on the WRITE side. For the database name enter "Addresses.sqlite" and enable the following "General" tab options:

  • Create database if it does not exist
  • Insert table if it does not exist
  • Insert data
  • Empty the table before importing

Once you have done this, switch to the "Fields / Data types" tab and unless it already exists type "t_Addresses" for the table name. It is necessary in this case, because when our SQLite database does not already exist we cannot select a table. Now we have to inform the SQLite Adapter which field of our CSV file should be used as a primary key. For this, click on the field list of the field ID, set the FlowHeater data type to integer and check the option "PrimaryKey" for this field. Close the Configurator popup of the SQLite Adapter with OK.

Now we must connect the fields of the CSV text file (READ side) with the fields of the SQLite database table (WRITE side). After this, we can import the CSV file into our SQLite database. Run this Definition once and store it with "Import-CSV-into-SQLite.fhd" as file name.

 

Import Excel worksheet into the SQLite database

We create another new FlowHeater Definition and for this select the Excel Adapter for the READ side and the SQlite Adapter for the WRITE side. Next we configure the Excel Adapter so that the Excel worksheet "Excel-Data.xls" can be read.

After this we open the Configurator for the SQLite Adapter on the WRITE side and select the same database "Addresses.sqlite" that we created in the previous steps. Enable in the "General" tab only the following options:

  • Add fields that do not exist to the table
  • Update data

And then switch to the "Fields / Data types" tab. The only thing to do here is to select the table "t_Addresses" from the SQLite tables list and click the "Load Schema" button once to load the fields already assigned to the table. Then close the SQLite Configurator popup with OK.

Now connect the ID field of the Excel file (READ side) with the ID field of the SQLite Adapter (WRITE side). At present we lack equivalent fields for the two additional fields of the Excel list in our SQLite database table. However, because we checked the "Add fields that do not exist to the table" option we can simply drag these fields to an empty area of the SQLite Adapter in the Designer. The SQLite Adapter automatically inserts these fields into the table and so amends the table schema for the new structure.

When you now run the Definition the SQLite table will be extended by two new fields and FlowHeater updates the table with data from the Excel file according to the ID field (PrimaryKey) into the SQLite database. Store this Definition with "Import-Excel-into-SQLite.fhd " as file name.

 

Export SQLite table as a flat file report

With our first two Definitions we have succeeded in consolidating the data from two sources (CSV and Excel) together. All that remains is to export the consolidated data as a flat file report. Create another new Definition and select for the READ side the SQLite Adapter and for the WRITE side the Textfile Adapter.

Open the SQLite Configurator and enter for the database name "Addresses.sqlite" to access the same database we created previously . Next switch to the "Fields / Data types" tab and select the "t_Addresses" table, initialize the fields list by clicking the "Load Schema" button and close the popup with OK.

Now open the TextFile Adapter Configurator on the WRITE side. Enter a file name for the output and amend the standard "Delimitation" option from "with delimiter" to "fixed width". Next switch to the "Fields / Data types" tab and click on the "Adopt the READ fields" button. Then close the Configurator popup with OK. Now we just have to connect the fields of the SQLite database (READ side) with the fields of the TextFile Adapter (WRITE side) and we can then start the export process. Store this Definition with "Export-SQLite-FlatFile.fhd" as file name.

 

Running automatically with the Batch Module

Using the Batch Module and the following CMD script you can automate the above 3 steps and potentially run these Definitions as a scheduled process via the Windows task planner.

@echo off
REM As necessary, amend for the installed path for FHBatch.exe
set FHBATCH="C:\Program Files\FlowHeater V2\BIN\FHBatch.exe"

REM Step 1: Export CSV to SQLite Datenbank
%FHBATCH% Import-CSV-into-SQLite.fhd

REM Step 2: Enrich the SQLite data with the Excel worksheet
%FHBATCH% Import-Excel-into-SQLite.fhd

REM Step 3: Export flat file report from the SQLite database
%FHBATCH% Export-SQLite-FlatFile.fhd