> For the complete documentation index, see [llms.txt](https://mariadb.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mariadb.com/docs/connectors/mariadb-connector-c/api-functions/mariadb_cancel.md).

# mariadb\_cancel

## Syntax

```c
int mariadb_cancel(MYSQL * mysql);
```

## Parameter

* `mysql` - mysql handle, which was previously allocated by [mysql\_init()](/docs/connectors/mariadb-connector-c/api-functions/mysql_init.md) or [mysql\_real\_connect()](/docs/connectors/mariadb-connector-c/api-functions/mysql_real_connect.md).

## Description

Immediately aborts a connection by making all subsequent read/write operations fail.*mariadb\_cancel()* does not invalidate memory used for mysql structure, nor close any communication channels. To free the memory, [mysql\_close()](/docs/connectors/mariadb-connector-c/api-functions/mysql_close.md) must be called.*mariadb\_cancel()* is useful to break long queries in situations where sending KILL is not possible.

## Return Value

Returns zero on success or a non-zero value on error.

## History

`mariadb_cancel()` was added in Connector/C 3.0

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