startswith operator
Filters a record set for data with a case-insensitive string starting sequence.
The following table provides a comparison of the startswith operators:
| Operator | Description | Case-Sensitive | Example (yields true) |
|---|---|---|---|
startswith |
RHS is an initial subsequence of LHS | No | "Fabrikam" startswith "fab" |
!startswith |
RHS isn't an initial subsequence of LHS | No | "Fabrikam" !startswith "kam" |
startswith_cs |
RHS is an initial subsequence of LHS | Yes | "Fabrikam" startswith_cs "Fab" |
!startswith_cs |
RHS isn't an initial subsequence of LHS | Yes | "Fabrikam" !startswith_cs "fab" |
Note
The following abbreviations are used in the table above:
- RHS = right hand side of the expression
- LHS = left hand side of the expression
For further information about other operators and to determine which operator is most appropriate for your query, see datatype string operators.
Case-insensitive operators are currently supported only for ASCII-text. For non-ASCII comparison, use the tolower() function.
Performance tips
Note
Performance depends on the type of search and the structure of the data.
For faster results, use the case-sensitive version of an operator, for example, hassuffix_cs, not hassuffix. For best practices, see Query best practices.
Syntax
T | where col startswith (expression)
Arguments
- T - The tabular input whose records are to be filtered.
- col - The column to filter.
- expression - Scalar or literal expression.
Returns
Rows in T for which the predicate is true.
Example
StormEvents
| summarize event_count=count() by State
| where State startswith "Lo"
| where event_count > 10
| project State, event_count
Output
| State | event_count |
|---|---|
| LOUISIANA | 463 |