---
metadata:
  - name: generator
    content: Diplodoc Platform v5.50.6
alternate:
  - https://ydb.tech/docs/en/yql/reference/syntax/not_yet_supported.md
  - https://ydb.tech/docs/ru/yql/reference/syntax/not_yet_supported.md
sourcePath: en/core/yql/reference/syntax/not_yet_supported.md
---
> **Documentation Index:** Fetch the complete configuration index at https://ydb.tech/docs/en/llms.txt

# Classic SQL constructs not supported yet

## \[NOT\] \[EXISTS|INTERSECT\|EXCEPT] {#not-exists}

A syntactically available alternative is `EXISTS`, but it's not very useful as it doesn't support correlated subqueries. You can also rewrite it using `JOIN`.

## NATURAL JOIN {#natural-join}

An alternative is to explicitly list the matching columns on both sides.

## NOW() / CURRENT_TIME() {#now}

An alternative is to use the functions [CurrentUtcDate, CurrentUtcDatetime and CurrentUtcTimestamp](https://ydb.tech/docs/en/yql/reference/builtins/basic.md#current-utc).