join

Concatenate string values within a group using a delimiter.

Syntax

join(StringExpression, Delimiter)

• StringExpression: the string to collect.
• Delimiter: string separator; defaults to "," when omitted.

column - The string column to join.
delimiter - The string to use as a separator between values.

Return Value

A single string with all values joined by the delimiter.

Example

Used inside summarize.

Join strings per group:

datatable(group:string, val:string)["A", "foo", "A", "bar", "B", "baz"]
| summarize joined = join(val, ",") by group

Collect unique pages per user:

pageviews
| where timestamp > ago(1h)
| summarize pages = join(page, " | ") by userId