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.
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Each book explains LOOKUP in context, with comparison tables and the common traps.
Terms in this definition
- Visual calculation
Defined on one visual instead of within the model, so only fields shown by that visual are usable. Good for running totals, moving averages or percentages of a total.
- DAX
Short for Data Analysis Expressions, the formula language you write measures, calculated columns and row-level security rules in, within tabular semantic models in Power BI, Excel Power Pivot or Analysis Services.
- Visual matrix
Visual calculations operate over this layout, which shows up in their edit mode as rows and columns, plus row pages if small multiples are used. Anything outside the visual, such as other model tables, can't be referenced.
Related terms
- COALESCE
Picks the first argument that is not NULL. In T-SQL loads this is often used to replace a missing lookup result with an Unknown member key such as -1.
- Custom variables
Values you define once in a Declarative Automation Bundle, under
variables, and reuse anywhere as${var.<name>}. A variable can carry a fallback value, fetch an object's ID by lookup, or be declaredtype: complex, and everything is filled in when you deploy. - LOOKUPVALUE
A DAX function that finds the row satisfying one or more search conditions and returns the value from a chosen result column, much like a lookup that doesn't need a relationship. Visual calculations can't use it.
- Point query
An Azure Table storage lookup that supplies both the PartitionKey and the RowKey, so exactly one entity comes back; this is the fastest kind of query the service offers.
- privatelink.vaultcore.azure.net
Zone used by Key Vault private endpoints. Unless it exists and is linked to the VNet, a lookup of the vault name returns the public IP rather than the private one.
- PTR
Turns an IP address back into a host name. These records live in reverse lookup zones.
- RELATED
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.