hasprefix_cs operator

Article
09/30/2024

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

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

For best performance, use strings of three characters or more. hasprefix_cs 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.

The following table compares the hasprefix operators using the abbreviations provided:

RHS = right-hand side of the expression
LHS = left-hand side of the expression

Operator	Description	Case-Sensitive	Example (yields `true`)
`hasprefix`	RHS is a term prefix in LHS	No	`"North America" hasprefix "ame"`
`!hasprefix`	RHS isn't a term prefix in LHS	No	`"North America" !hasprefix "mer"`
`hasprefix_cs`	RHS is a term prefix in LHS	Yes	`"North America" hasprefix_cs "Ame"`
`!hasprefix_cs`	RHS isn't a term prefix in LHS	Yes	`"North America" !hasprefix_cs "CA"`

For more information about other operators and to determine which operator is most appropriate for your query, see datatype string operators.

Performance tips

Note

Performance depends on the type of search and the structure of the data. For best practices, see Query best practices.

Syntax

T | where Column hasprefix_cs (Expression)

Learn more about syntax conventions.

Parameters

Name	Type	Required	Description
T	`string`	✔️	The tabular input whose records are to be filtered.
Column	`string`	✔️	The column used to filter.
Expression	`string`	✔️	The expression for which to search.

Returns

Rows in T for which the predicate is true.

Examples

Run the query

StormEvents
| summarize event_count=count() by State
| where State hasprefix_cs "P"
| count

Count
3