====== SQL Event Source ======

===== Overview =====

**SQL Event Source** is a datacore event source for databases. It provides low-level support to define a database connection and query that polls for data. It supports SQL Server, OLE DB, ODBC, Oracle, EntityClient and SQL Server Compact 4.0.

===== Event Message Structure =====

Records from the SQL source are converted to the Data Core Event Message structure, with columns becoming Event Properties.

===== Requirements =====

==== DB Providers ====
DB Providers must be installed on the server hosting App Store Connect. \\ (The .Net framework includes most key providers. [[https://msdn.microsoft.com/en-us/library/a6cd7c08(v=vs.110).aspx|More info...]])

==== Read-Only Data Access ====
The Event Source can connect to a database using windows impersonation or with credentials explicitly specified in the connection string (encrypted). However, in both cases, you should only provide an account with read-only access to the subset of data you are prepared to share.

===== Configuration =====

  * SQL Provider: DB drivers installed on server 
  * Connection String: The connection string for the remote database.
  * SQL Query: The SQL query string to use when requesting events from the database.
  * Primary Key: A numeric incrementing PK is required to track data-processing progress. This must be returned by the query.
  * Sleep Period: Interval to rest if no data is returned.

==== Example SQL Query  ====


<code SQL SQL Query>

SELECT TOP 50
  [MessageDataID],
  *
  FROM [dbo].[Archiver1_MasterEventLog_Col1_Con1]
  WHERE  MessageDataID > {0}
    ORDER BY MessageDataID
    
</code>

The SQL Query should look something like the above and include the following parts:

  * A Top clause so data is queried and returned in batches.
  * The source-data must contain a Primary Key (e.g. "MessageDataID")
  * A Where filter on the source-data primary key with placeholder (e.g. WHERE MessageDataID > {0}). This allows us to pick-up and move on to the next batch of data.