ES|QL implicit casting
editES|QL implicit casting
editOften users will input date
, date_period
, time_duration
, ip
or version
as simple strings in their queries for use in predicates, functions, or expressions. ES|QL provides type conversion functions to explicitly convert these strings into the desired data types.
Without implicit casting users must explicitly code these to_X
functions in their queries, when string literals don’t match the target data types they are assigned or compared to. Here is an example of using to_datetime
to explicitly perform a data type conversion.
FROM employees | EVAL dd_ns1=date_diff("day", to_datetime("2023-12-02T11:00:00.00Z"), birth_date) | SORT emp_no | KEEP dd_ns1 | LIMIT 1
Implicit casting example
editImplicit casting automatically converts string literals to the target data type. This allows users to specify string values for types like date
, date_period
, time_duration
, ip
and version
in their queries.
The first query can be coded without calling the to_datetime
function, as follows:
FROM employees | EVAL dd_ns1=date_diff("day", "2023-12-02T11:00:00.00Z", birth_date) | SORT emp_no | KEEP dd_ns1 | LIMIT 1
Operations that support implicit casting
editThe following table details which ES|QL operations support implicit casting for different data types.
ScalarFunctions | Operators | GroupingFunctions | AggregateFunctions | |
---|---|---|---|---|
DATE |
Y |
Y |
Y |
N |
DATE_PERIOD/TIME_DURATION |
Y |
N |
Y |
N |
IP |
Y |
Y |
Y |
N |
VERSION |
Y |
Y |
Y |
N |
BOOLEAN |
Y |
Y |
Y |
N |
ScalarFunctions includes:
Operators includes: