Tabular expression statements

The tabular expression statement is what people usually have in mind when they talk about queries. This statement usually appears last in the statement list, and both its input and its output consists of tables or tabular datasets. Any two statements must be separated by a semicolon.

A tabular expression statement is generally composed of tabular data sources such as tables, tabular data operators such as filters and projections, and optional rendering operators. The composition is represented by the pipe character (|), giving the statement a regular form that visually represents the flow of tabular data from left to right. Each operator accepts a tabular dataset “from the pipe”, and other inputs including more tabular datasets from the body of the operator, then emits a tabular dataset to the next operator that follows.

Syntax

Source | Operator1 | Operator2 | RenderInstruction

Parameters

Tabular data sources

A tabular data source produces sets of records, to be further processed by tabular data operators. The following list shows supported tabular data sources:

• Table references
• The tabular range operator
• The print operator
• An invocation of a function that returns a table
• A table literal (“datatable”)

Examples

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

Filter rows by condition

This query counts the number of records in the StormEvents table that have a value of “FLORIDA” in the State column.

StormEvents 
| where State == "FLORIDA"
| count

Output

Combine data from two tables

In this example, the join operator is used to combine records from two tabular data sources: the StormEvents table and the PopulationData table.

StormEvents 
| where InjuriesDirect + InjuriesIndirect > 50
| join (PopulationData) on State
| project State, Population, TotalInjuries = InjuriesDirect + InjuriesIndirect

Output