> 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/server/reference/sql-statements/geometry-constructors/geometry-properties/st_isring.md).

# ST\_IsRing

## Syntax

```bnf
ST_IsRing(g)
IsRing(g)
```

## Description

Returns true if a given [LINESTRING](/docs/server/reference/sql-statements/geometry-constructors/geometry-constructors/linestring.md) is a ring, that is, both [ST\_IsClosed](/docs/server/reference/sql-statements/geometry-constructors/geometry-properties/st_isclosed.md) and [ST\_IsSimple](/docs/server/reference/sql-statements/geometry-constructors/geometry-properties/st_issimple.md). A simple curve does not pass through the same point more than once. However, see [MDEV-7510](https://jira.mariadb.org/browse/MDEV-7510).

`St_IsRing()` and `IsRing()` are synonyms.

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