MartijnVisser commented on a change in pull request #18813:
URL: https://github.com/apache/flink/pull/18813#discussion_r823679233
##########
File path: docs/content/docs/dev/table/types.md
##########
@@ -1487,6 +1481,88 @@ Not supported.
{{< /tab >}}
{{< /tabs >}}
+Casting
+-------
+
+Flink SQL can perform casting between a defined pair `from` type and `target`
type pair. While some
+casting operations can always succeed regardless of the input value, others
can fail at runtime
+(i.e. where there is no way to create a value for the target type). For
example, it is always
+possible to convert `INT` to `STRING`, but you cannot always convert a
`STRING` to `INT`.
+
+During the planning stage, Flink SQL rejects queries for invalid cast input
and target type with
+a `ValidationException`, e.g. when trying to cast a `TIMESTAMP` to an
`INTERVAL`.
+While for valid type pairs that can fail at runtime Flink SQL accepts them,
but requires the user to correctly handle failures.
Review comment:
```suggestion
Valid type pairs that can fail at runtime will be accepted by Flink Table
API and SQL, but requires the user to correctly handle failures.
```
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
