Features

Execute SQL statements within blueprints
Queries are ran asynchronously in UE4's async thread pool
Depending on query result size, hundreds of queries can execute at once without any noticeable lag on the game thread

Code Modules

How to create and execute a query in blueprints (See Blueprint Screenshot)

Construct a Query UObject
Bind the OnQueryFinished event
Add a DatabaseRowModel struct variable. The DatabaseRowModel should contain the array of DatabaseColumnModels which contains the column name and variable type definitions. The StringBufferSize is only needed for string columns
Call ExecuteQueryAsync on the DatabaseQuery object
A DatabaseQueryResult should be returned populated with results
You can GetValueAsString on a result column or cast it to it's variable type column to avoid converting it to a string

Behind the scenes:

DatabaseQueryResult UObject is created on the game thread
FNonAbandonableTask is created and begins to run on it's own thread
A connection is created to the SQL database
QueryResultRowStructs are created for each result row and populated by ODBC SQLFetch()
FNonAbandonableTask returns the populated QueryResultStruct to the game thread
Game thread converts the QueryResultStructs to the UDatabaseQueryResults
The blueprint friendly OnQueryFinished is broadcast with the populated UDatabaseQueryResult

John Poole

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