elasticsearch/docs/reference/esql/processing-commands/eval.asciidoc

[discrete]
[[esql-eval]]
=== `EVAL`

**Syntax**

[source,esql]
----
EVAL column1 = value1[, ..., columnN = valueN]
----

*Parameters*

`columnX`::
The column name.

`valueX`::
The value for the column. Can be a literal, an expression, or a
<<esql-functions,function>>.

*Description*

The `EVAL` processing command enables you to append new columns with calculated
values. `EVAL` supports various functions for calculating values. Refer to
<<esql-functions,Functions>> for more information.

*Examples*

[source.merge.styled,esql]
----
include::{esql-specs}/docs.csv-spec[tag=eval]
----
[%header.monospaced.styled,format=dsv,separator=|]
|===
include::{esql-specs}/docs.csv-spec[tag=eval-result]
|===

If the specified column already exists, the existing column will be dropped, and
the new column will be appended to the table:

[source.merge.styled,esql]
----
include::{esql-specs}/docs.csv-spec[tag=evalReplace]
----
[%header.monospaced.styled,format=dsv,separator=|]
|===
include::{esql-specs}/docs.csv-spec[tag=evalReplace-result]
|===