> 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-functions/string-functions/insert-function.md).

# INSERT Function

## Syntax

```bnf
INSERT(str,pos,len,newstr)
```

## Description

Returns the string `str`, with the substring beginning at position `pos` and `len` characters long replaced by the string `newstr`. Returns the original string if `pos` is not within the length of the string.\
Replaces the rest of the string from position `pos` if `len` is not within the length of the rest of the string. Returns `NULL` if any argument is `NULL`.

## Examples

```sql
SELECT INSERT('Quadratic', 3, 4, 'What');
+-----------------------------------+
| INSERT('Quadratic', 3, 4, 'What') |
+-----------------------------------+
| QuWhattic                         |
+-----------------------------------+

SELECT INSERT('Quadratic', -1, 4, 'What');
+------------------------------------+
| INSERT('Quadratic', -1, 4, 'What') |
+------------------------------------+
| Quadratic                          |
+------------------------------------+

SELECT INSERT('Quadratic', 3, 100, 'What');
+-------------------------------------+
| INSERT('Quadratic', 3, 100, 'What') |
+-------------------------------------+
| QuWhat                              |
+-------------------------------------+
```

<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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