# **JSON_UNQUOTE()**

## **Function Description**

The `JSON_UNQUOTE()` function is used to extract a JSON value without quotes from a JSON string and return it as a string.

Specifically, the `JSON_UNQUOTE()` function takes a `JSON` string as input, and then extracts a `JSON` value from it and returns it as a string. If the entered `JSON` string does not contain a valid `JSON` value or the parameter is `NULL`, the function returns `NULL`. If the parameter is NULL, NULL is returned. An error occurs if the value starts and ends with double quotes but is not a valid `JSON` string literal.

## **Grammar Structure**

```sql
select JSON_UNQUOTE(string_value);
```

In a string, some sequences have special meanings, and these sequences start with a backslash (\), called escape characters, and the rules are as follows. For all other escape sequences, the backslash will be ignored. That is, escape characters are interpreted as having no escape. For example, \x is x. These sequences are case sensitive. For example, \b is interpreted as a backspace, while \B is interpreted as B.

|Escape sequence | Characters represented |
|---|--|
|\"|Double Quotes (") |
|\b|Backspace symbol|
|\f|Page change|
|\n|Line Newlines|
|\r|Carriage Return|
|\t|Tabs|
|\\|Backslash (\) |
|\uXXXX|Unicode UTF-8 bytes with XXXX|

## **Example**

```text
mysql> SET @j = '"abc"';
Query OK, 0 rows affected (0.00 sec)

mysql> SELECT @j, JSON_UNQUOTE(@j);
+-----------------------------------+
| @j | json_unquote(@j) |
+-----------------------------------+
| "abc" | abc |
+-----------------------------------+
1 row in set (0.00 sec)

mysql> SET @j = '[1, 2, 3]';
Query OK, 0 rows affected (0.00 sec)

mysql> SELECT @j, JSON_UNQUOTE(@j);
+----------------------------------------+
| @j | json_unquote(@j) |
+----------------------------------------+
| [1, 2, 3] | [1, 2, 3] |
+----------------------------------------+
1 row in set (0.00 sec)

mysql> SELECT JSON_UNQUOTE('"\\t\\u0032"');
+----------------------------------+
| json_unquote("\\t\\u0032") |
+----------------------------------+
| 2 |
+----------------------------------+
1 row in set (0.00 sec)
```