> ## Documentation Index
> Fetch the complete documentation index at: https://private-7c7dfe99-fix-nav-issues.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

> Documentation for EXECUTE AS Statement

# EXECUTE AS Statement

export const CloudNotSupportedBadge = () => {
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            Not supported in ClickHouse Cloud
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};

Allows to execute queries on behalf of a different user.

<h2 id="syntax">
  Syntax
</h2>

```sql theme={null}
EXECUTE AS target_user;
EXECUTE AS target_user subquery;
```

The first form (without `subquery`) sets that all the following queries in the current session will be executed on behalf of the specified `target_user`.

The second form (with `subquery`) executes only the specified `subquery` on behalf of the specified `target_user`.

In order to work both forms require config setting `access_control_improvements.allow_impersonate_user`
to be set to `1` and the `IMPERSONATE` privilege to be granted. For example, the following commands

```sql theme={null}
GRANT IMPERSONATE ON user1 TO user2;
GRANT IMPERSONATE ON * TO user3;
```

allow user `user2` to execute commands `EXECUTE AS user1 ...` and also allow user `user3` to execute commands as any user.

While impersonating another user function [currentUser()](/reference/functions/regular-functions/other-functions#currentUser) returns the name of that other user,
and function [authenticatedUser()](/reference/functions/regular-functions/other-functions#authenticatedUser) returns the name of the user who has been actually authenticated.

<h2 id="examples">
  Examples
</h2>

```sql theme={null}
SELECT currentUser(), authenticatedUser(); -- outputs "default    default"
CREATE USER james;
EXECUTE AS james SELECT currentUser(), authenticatedUser(); -- outputs "james    default"
```