Fetches a column value from the lookup table, that is the one side of a many-to-one relationship, for whichever row is being evaluated. It therefore needs to run inside an iterator or a calculated column, where row context exists.
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Terms in this definition
- LOOKUP
Inside a visual calculation, this DAX function retrieves a value from the visual matrix using whatever filters you supply, and works out any you omit from the context it is evaluated in.
- Event
Table in Log Analytics where entries from Windows event logs are kept.
- Iterator
A DAX function like SUMX that steps through a table one row at a time, evaluating an expression in row context, and then aggregates what it gets.
- Calculated column
A new column whose DAX formula is worked out for each row when the data refreshes, with the results kept in the model and so increasing its size. Because the values are stored, it can be used in slicers, filters, rows and axes, which a measure cannot.
- WHERE
Limits a SELECT, UPDATE or DELETE to just the rows meeting a condition. Omit it, and the statement hits every row.
- Row context
Exists automatically in calculated columns and inside iterators like SUMX, giving DAX a current row to work on. Filtering the model is left to filter context; a current row does not do that by itself.
Related terms
- Alert story
Shown on a Defender alert page as a process tree: what came before the alert (related events and other alerts), what happened next, and entities that can be expanded for more detail.
- AlertInfo
Holds one row per alert from onboarded Sentinel workspaces and the Defender products, giving the alert's severity, category and title, its detection source and mapped MITRE ATT&CK techniques. Combine it with AlertEvidence using AlertId when you need the related entities.
- App launchers
Here administrators group related apps into My Apps collections, each appearing as a separate tab for users. It sits in the Enterprise apps blade, needs Entra ID P1 or P2, and only organises apps people could already open rather than granting new access.
- View
Shows a system through one chosen group of related concerns. No view is generic; each one is tied to whichever architecture it depicts.
- AuditIfNotExists
Azure Policy effect that flags a resource as non-compliant if a related resource, identified by details.type and matching existenceCondition, is absent. It only reports and never deploys anything.
- Blank row
When fact rows carry a key that doesn't exist in the related one-side table, a regular relationship gathers them under an added virtual row, so referential integrity problems surface as (Blank). Limited relationships don't do this.
- Column-family database
A NoSQL database that still has rows and columns, but organises related columns into named groups called column families. Apache Cassandra works this way.
- DeployIfNotExists
When a related resource is absent, this Azure Policy effect deploys an ARM template to create it. Resources that already exist are corrected only by a remediation task running as the assignment's managed identity.