AnyLog query node

SparkStudio can use an AnyLog query node as a named-query connection. You write the same kind of SELECT used for SQL Server. The connector sends that statement as an HTTP GET. The command header is:

sql <dbms> format=json <select>

The header destination: network is the REST form of run client (). Putting run client () in a POST body makes this node return HTTP 400, Unrecognized Command. format=json is added so screens receive columns and rows. The SELECT text itself is not rewritten. @name parameters are still declared on the named query; before the command is sent, each one is replaced with a typed literal. AnyLog's REST command does not accept a separate parameter list.

The connector requires Windows preview.16, Docker preview.16-docker.1 or a later compatible build. This connector is a plugin under plugins/anylog/, contributed from a community fork. SparkStudio core only has a small registration seam for read-only database connectors; the seam and how another connector can use it are described in plugins/anylog/PLUGIN_SEAM.md.

Create the connection

Open Gateway Settings → Data → Connections → New Connection and choose AnyLog query node. The choice appears when the gateway was built with the plugin and has loaded plugins/SparkStudio.Connectors.AnyLog.dll.

Save, then Test connection. The test sends get status in the command header. A successful test means the node accepted a command. It does not prove that the DBMS contains a particular table; run a named query for that.

The connection is read-only. Named queries on it stay Rows (SELECT). INSERT, UPDATE and DELETE, including atomic table batches, stay on SQLite and SQL Server.

Write the query

In the project, create a named query and choose the AnyLog connection. Example:

SELECT sensor, value
FROM temperature
WHERE sensor = @sensor AND timestamp >= NOW() - 1 hour

With DBMS aloperator and @sensor set to BCT, the node receives:

sql aloperator format=json SELECT sensor, value FROM temperature WHERE sensor = 'BCT' AND timestamp >= NOW() - 1 hour

Parameter rules match the SQL Server named-query types: string, integer, long, floating point, decimal, boolean, date and GUID. Strings are single-quoted and embedded quotes are doubled. Numbers stay numeric literals. Missing values become NULL. Placeholders inside quotes are left as written. Comments are removed before sending.

AnyLog's own SQL limits still apply. A query is one statement, normally one table. Joins, nested queries and T-SQL TOP are outside what a query node typically accepts; use LIMIT and AnyLog's NOW() - N hours/days/minutes form. The connector still refuses a statement that is not a single SELECT or WITH … SELECT, and it refuses stacked statements.

The node returns a JSON object. Table rows are the objects in Query. Statistics is not shown as table data. Results are capped at 1,000 rows, about 16 MiB and 1 MiB per cell, with a 30-second limit. A larger result fails instead of returning a partial table. Screens, dropdowns, lists and query tables bind to the named query the same way they bind to a SQL Server query.

The gateway calls http://<address>:<port>/ with User-Agent: AnyLog/1.23. The command travels in the command header, and a query also sends destination: network. A line break in the SELECT becomes a space in that header, so -- and /* */ comments are removed first. The command is limited to 3,500 characters of printable ASCII; a SELECT or parameter value with accented or other non-ASCII characters is rejected with a message instead of being sent.

Build and test

From the repository root:

dotnet run --project plugins/anylog/SparkStudio.Connectors.AnyLog.Tests
dotnet build src/SparkStudio.Gateway

The gateway build compiles the plugin and copies SparkStudio.Connectors.AnyLog.dll into the gateway output plugins/ folder. Restart the gateway after that copy. Publishing the gateway copies the same file into the published plugins/ folder.

The connector tests cover command wrapping, parameter quoting, the SELECT screen, JSON rows and plugin loading. They do not contact a live query node.