# LENGTH

## Syntax

```sql
LENGTH(str)
```

## Description

Returns the length of the string `str`.

In the default mode, when [Oracle mode](https://app.gitbook.com/s/aEnK0ZXmUbJzqQrTjFyb/community-server/about/compatibility-and-differences/sql_modeoracle) is not set, the length is measured in bytes. In this case, a multi-byte character counts as multiple bytes. `LENGTH()` returns the length in bytes, whereas `CHAR_LENGTH()` returns the number of characters. This means that, for a string containing five two-byte characters, `LENGTH()` returns 10, whereas [CHAR\_LENGTH()](https://mariadb.com/docs/server/reference/sql-functions/string-functions/char_length) returns 5. When running Oracle mode, the length is measured in characters, and `LENGTH` is a synonym for [CHAR\_LENGTH()](https://mariadb.com/docs/server/reference/sql-functions/string-functions/char_length).

If `str` is not a string value, it is converted into a string. If `str` is `NULL`, the function returns `NULL`.

## Examples

```sql
SELECT LENGTH('MariaDB');
+-------------------+
| LENGTH('MariaDB') |
+-------------------+
|                 7 |
+-------------------+
```

When Oracle mode is not set:

```sql
SELECT CHAR_LENGTH('π'), LENGTH('π'), LENGTHB('π'), OCTET_LENGTH('π');
+-------------------+--------------+---------------+--------------------+
| CHAR_LENGTH('π')  | LENGTH('π')  | LENGTHB('π')  | OCTET_LENGTH('π')  |
+-------------------+--------------+---------------+--------------------+
|                 1 |            2 |             2 |                  2 |
+-------------------+--------------+---------------+--------------------+
```

In Oracle mode:

```sql
SELECT CHAR_LENGTH('π'), LENGTH('π'), LENGTHB('π'), OCTET_LENGTH('π');
+-------------------+--------------+---------------+--------------------+
| CHAR_LENGTH('π')  | LENGTH('π')  | LENGTHB('π')  | OCTET_LENGTH('π')  |
+-------------------+--------------+---------------+--------------------+
|                 1 |            1 |             2 |                  2 |
+-------------------+--------------+---------------+--------------------+
```

## See Also

* [CHAR\_LENGTH()](https://mariadb.com/docs/server/reference/sql-functions/string-functions/char_length)
* [LENGTHB()](https://mariadb.com/docs/server/reference/sql-functions/string-functions/lengthb)
* [OCTET\_LENGTH()](https://mariadb.com/docs/server/reference/sql-functions/string-functions/octet_length)
* [Oracle mode](https://app.gitbook.com/s/aEnK0ZXmUbJzqQrTjFyb/community-server/about/compatibility-and-differences/sql_modeoracle)

<sub>*This page is licensed: GPLv2, originally from*</sub> [<sub>*fill\_help\_tables.sql*</sub>](https://github.com/MariaDB/server/blob/main/scripts/fill_help_tables.sql)

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