[hotfix][docs][table] Fix typo in User-defined Functions

[KarmaGYZ]

What is the purpose of the change

This PR Fix typo in User-defined Functions

Brief change log

• Revert all Types.TIMESTAMP to Types.SQL_TIMESTAMP
• Remove redundant brackets

Verifying this change

This change is a trivial rework / code cleanup without any test coverage.

Does this pull request potentially affect one of the following parts (all no):

• Dependencies (does it add or upgrade a dependency): (yes / no)
• The public API, i.e., is any changed class annotated with @Public(Evolving): (yes / no)
• The serializers: (yes / no / don't know)
• The runtime per-record code paths (performance sensitive): (yes / no / don't know)
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Yarn/Mesos, ZooKeeper: (yes / no / don't know)
• The S3 file system connector: (yes / no / don't know)

Documentation

• Does this pull request introduce a new feature? no

[hequn8128]

@KarmaGYZ Hi, thanks a lot for the fix. I found same Types.TIMESTAMP and Types.STRING() errors in other docs(such as connect.md and common.md). Would be geat if you also fix it. It is both ok to fix them in this PR or create another one.

Best, Hequn

[sunjincheng121]

Thanks @KarmaGYZ and @hequn8128, udfs.md also has such a mistake. And I recommended to search globally for associated docs in the IDE. +1 for @hequn8128's suggestion.

Thanks,
Jincheng,

[KarmaGYZ]

Thanks for the advice @hequn8128 and @sunjincheng121 !
I push a new commit address the review:

• Fix all mistake types in other doc
• For the brackets, I find there are three Types class defined in Flink project: org.apache.flink.api.common.typeinfo.Types, org.apache.flink.api.scala.Types and org.apache.flink.table.api.Types. The last one enumerates all supported types of the Table API & SQL. So in doc of Table API & SQL domain, we should use this one and in Java code the brackets are necessary. So I add the missing brackets for associated docs.