fabric-eventhouselisted

# Fabric Eventhouse / KQL Database KQL management and query patterns specific to Fabric Eventhouse. Assumes familiarity with KQL — focus is on Fabric-specific behavior and az-rest-driven workflows. ## Connection - **Cluster URI**: each KQL Database has its own `queryServiceUri`, `https://<cluster>.kusto.fabric.microsoft.com`. Discover with `GET /v1/workspaces/{wsId}/kqlDatabases` (returns `queryServiceUri` + `databaseName` per item). - **Token audience**: `https://kusto.kusto.windows.net/.default` for all direct access. A wrong audience surfaces as a 401 *"Request is invalid and cannot be processed"*, not an auth error. - **Query endpoint**: `POST {clusterUri}/v1/rest/query`, body `{"db":"<dbName>", "csl":"<KQL>"}`. - **KQL `|` breaks shell escaping** — write the JSON body to a temp file and pass `--body @<file>`, never inline. Worked `az rest` invocation and the REST item-definition envelope: [references/programmatic-access.md](references/programmatic-access.md). ## Schema Discovery ```kql .show tables .show table T schema as json // column names + types .show table T details // row count, extent count, size .show functions .show materialized-views .show database principals // who has what role ``` ## Schema Evolution - **`.create-merge table`** is the safe / idempotent form — adds missing columns, never drops existing. Prefer over `.create table` for repeatable deployments. - `.alter-merge table T (NewCol: string)` — add