PowerShell Scripting to Replicate Neo4J Data to MySQL

The CData Cmdlets for Neo4J offer live access to Neo4J 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 Neo4J and the CData Cmdlets for MySQL in PowerShell to replicate Neo4J data to a MySQL database.

After obtaining the needed connection properties, accessing Neo4J data in PowerShell and preparing for replication consists of four basic steps.

To connect to Neo4j, set the following connection properties:

• Server: The server hosting the Neo4j instance.
• Port: The port on which the Neo4j service is running. The provider connects to port 7474 by default.
• User: The username of the user using the Neo4j instance.
• Password: The password of the user using the Neo4j instance.

Collecting Neo4J Data

1. Install the module:

   Install-Module Neo4jCmdlets

2. Connect to Neo4J:

   $neo4j = Connect-Neo4j -Server $Server -Port $Port -User $User -Password $Password

3. Retrieve the data from a specific resource:

   $data = Select-Neo4j -Connection $neo4j -Table "ProductCategory"

   You can also use the Invoke-Neo4j cmdlet to execute pure SQL-92 statements:

   $data = Invoke-Neo4j -Connection $neo4j -Query 'SELECT * FROM ProductCategory WHERE CategoryOwner = @CategoryOwner' -Params @{'@CategoryOwner'='CData Software'}

4. Save a list of the column names from the returned data.

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

Inserting Neo4J 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 Neo4J 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 Neo4J resource (ProductCategory) and to exist in the database.

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

You have now replicated your Neo4J data to a MySQL database. This gives you freedom to work with Neo4J 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 Neo4J and MySQL in PowerShell, you can pipe command results to perform the replication in a single line:

  Select-Neo4j -Connection $neo4j -Table "ProductCategory" | % { $row = $_ $values = @() $columns | % { $col = $_ $values += $row.$($col) } Add-MySQL -Connection $mysql -Table "ProductCategory" -Columns $columns -Values $values }

• If you wish to replicate the Neo4J 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-Neo4j 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')}