The case-insensitive hasprefix string operator

Filters a record set for data with a case-insensitive starting string.

For best performance, use strings of three characters or more. hasprefix searches for indexed terms, where a term is three or more characters. If your term is fewer than three characters, the query scans the values in the column, which is slower than looking up the term in the term index.

Performance tips

When possible, use the case-sensitive hasprefix_cs.

Syntax

T | where Column hasprefix (Expression)

Parameters

Returns

Rows in T for which the predicate is true.

Example

StormEvents
| summarize event_count=count() by State
| where State hasprefix "la"
| project State, event_count