ES|QL implicit castingedit
Often users will input datetime, ip, version, or geospatial objects 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 improves usability, by automatically converting string literals to the target data type. This is most useful when the target data type is datetime, ip, version or a geo spatial. It is natural to specify these as a string in 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
Implicit casting supportedit
The following table details which ES|QL operations support implicit casting for different data types.
| ScalarFunction | BinaryComparison | ArithmeticOperation | InListPredicate | AggregateFunction | ||
|---|---|---|---|---|---|---|
DATETIME |
Y |
Y |
Y |
Y |
N |
|
DOUBLE |
Y |
N |
N |
N |
N |
|
LONG |
Y |
N |
N |
N |
N |
|
INTEGER |
Y |
N |
N |
N |
N |
|
IP |
Y |
Y |
Y |
Y |
N |
|
VERSION |
Y |
Y |
Y |
Y |
N |
|
GEO_POINT |
Y |
N |
N |
N |
N |
|
GEO_SHAPE |
Y |
N |
N |
N |
N |
|
CARTESIAN_POINT |
Y |
N |
N |
N |
N |
|
CARTESIAN_SHAPE |
Y |
N |
N |
N |
N |
|
BOOLEAN |
Y |
Y |
Y |
Y |
N |