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project operator

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Applies to: ✅ Microsoft Fabric ✅ Azure Data Explorer ✅ Azure Monitor ✅ Microsoft Sentinel

Select the columns to include, rename or drop, and insert new computed columns.

The order of the columns in the result is specified by the order of the arguments. Only the columns specified in the arguments are included in the result. Any other columns in the input are dropped.

Syntax

T | project [ColumnName | (ColumnName[,]) =] Expression [, ...]

or

T | project ColumnName [= Expression] [, ...]

Learn more about syntax conventions.

Parameters

Name Type Required Description
T string ✔️ The tabular input for which to project certain columns.
ColumnName string A column name or comma-separated list of column names to appear in the output.
Expression string The scalar expression to perform over the input.
  • Either ColumnName or Expression must be specified.
  • If there's no Expression, then a column of ColumnName must appear in the input.
  • If ColumnName is omitted, the output column name of Expression will be automatically generated.
  • If Expression returns more than one column, a list of column names can be specified in parentheses. If a list of the column names isn't specified, all Expression's output columns with generated names will be added to the output.

Note

It's not recommended to return a new calculated column with the same name as an existing column in the input.

Returns

A table with columns that were named as arguments. Contains same number of rows as the input table.

Examples

The examples in this section show how to use the syntax to help you get started.

The examples in this article use publicly available tables in the help cluster, such as the StormEvents table in the Samples database.

The examples in this article use publicly available tables, such as the StormEvents table in the Weather analytics sample data.

Only show specific columns

Only show the EventId, State, EventType of the StormEvents table.

StormEvents
| project EventId, State, EventType

Output

The table shows the first 10 results.

EventId State EventType
61032 ATLANTIC SOUTH Waterspout
60904 FLORIDA Heavy Rain
60913 FLORIDA Tornado
64588 GEORGIA Thunderstorm Wind
68796 MISSISSIPPI Thunderstorm Wind
68814 MISSISSIPPI Tornado
68834 MISSISSIPPI Thunderstorm Wind
68846 MISSISSIPPI Hail
73241 AMERICAN SAMOA Flash Flood
64725 KENTUCKY Flood
... ... ...

Potential manipulations using project

The following query renames the BeginLocation column and creates a new column called TotalInjuries from a calculation over two existing columns.

StormEvents
| project StartLocation = BeginLocation, TotalInjuries = InjuriesDirect + InjuriesIndirect
| where TotalInjuries > 5

Output

The table shows the first 10 results.

StartLocation TotalInjuries
LYDIA 15
ROYAL 15
GOTHENBURG 9
PLAINS 8
KNOXVILLE 9
CAROL STREAM 11
HOLLY 9
RUFFIN 9
ENTERPRISE MUNI ARPT 50
COLLIERVILLE 6
... ...

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