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PowerShell Scripting to Replicate Quandl Data to MySQL

Write a simple PowerShell script to replicate Quandl data to a MySQL database.

The CData Cmdlets for Quandl offer live access to Quandl data from within PowerShell. Using PowerShell scripts, you can easily automate regular tasks like data replication. This article will walk through using the CData Cmdlets for Quandl and the CData Cmdlets for MySQL in PowerShell to replicate Quandl data to a MySQL database.

After obtaining the needed connection properties, accessing Quandl data in PowerShell and preparing for replication consists of four basic steps.

Quandl uses an API key for authentication. See the help documentation for a guide to obtaining the APIKey property.

Additionally, set the DatabaseCode connection property to the code identifying the Database whose Datasets you want to query with SQL. You can search the available Databases by querying the Databases view.

Collecting Quandl Data

  1. Install the module:

    Install-Module QuandlCmdlets
  2. Connect to Quandl:

    $quandl = Connect-Quandl -APIKey $APIKey -DatabaseCode $DatabaseCode
  3. Retrieve the data from a specific resource:

    $data = Select-Quandl -Connection $quandl -Table "AAPL"

    You can also use the Invoke-Quandl cmdlet to execute pure SQL-92 statements:

    $data = Invoke-Quandl -Connection $quandl -Query 'SELECT * FROM AAPL WHERE Collapse = @Collapse' -Params @{'@Collapse'='Daily'}
  4. Save a list of the column names from the returned data.

    $columns = ($data | Get-Member -MemberType NoteProperty | Select-Object -Property Name).Name

Inserting Quandl Data into the MySQL Database

With the data and column names collected, you are ready to replicate the data into a MySQL database.

  1. Install the module:

    Install-Module MySQLCmdlets
  2. Connect to MySQL, using the server address and port of the MySQL server, valid user credentials, and a specific database with the table in which the data will be replicated:

    $mysql = Connect-MySQL -User $User -Password $Password -Database $Database -Server $Server -Port $Port
  3. Loop through the Quandl data, store the values, and use the Add-MySQL cmdlet to insert the data into the MySQL database, one row at a time. In this example, the table will need to have the same name as the Quandl resource (AAPL) and to exist in the database.

    $data | % { $row = $_ $values = @() $columns | % { $col = $_ $values += $row.$($col) } Add-MySQL -Connection $mysql -Table "AAPL" -Columns $columns -Values $values }

You have now replicated your Quandl data to a MySQL database. This gives you freedom to work with Quandl data in the same way that you work with other MySQL tables, whether that is performing analytics, building reports, or other business functions.

Notes

  • Once you have connected to Quandl and MySQL in PowerShell, you can pipe command results to perform the replication in a single line:

    Select-Quandl -Connection $quandl -Table "AAPL" | % { $row = $_ $values = @() $columns | % { $col = $_ $values += $row.$($col) } Add-MySQL -Connection $mysql -Table "AAPL" -Columns $columns -Values $values }
  • If you wish to replicate the Quandl data to another database using another PowerShell module, you will want to exclude the Columns, Connection, and Table columns from the data returned by the Select-Quandl cmdlet since those columns are used to help pipe data from one CData cmdlet to another:

    $columns = ($data | Get-Member -MemberType NoteProperty | Select-Object -Property Name).Name | ? {$_ -NotIn @('Columns','Connection','Table')}