json.md

# JSON

Outputs data in JSON format. Besides data tables, it also outputs column names and types, along with some additional information: the total number of output rows, and the number of rows that could have been output if there weren't a LIMIT. Example:

```sql
SELECT SearchPhrase, count() AS c FROM test.hits GROUP BY SearchPhrase WITH TOTALS ORDER BY c DESC LIMIT 5 FORMAT JSON
```

```json
{
        "meta":
        [
                {
                        "name": "SearchPhrase",
                        "type": "String"
                },
                {
                        "name": "c",
                        "type": "UInt64"
                }
        ],

        "data":
        [
                {
                        "SearchPhrase": "",
                        "c": "8267016"
                },
                {
                        "SearchPhrase": "bathroom interior design",
                        "c": "2166"
                },
                {
                        "SearchPhrase": "yandex",
                        "c": "1655"
                },
                {
                        "SearchPhrase": "spring 2014 fashion",
                        "c": "1549"
                },
                {
                        "SearchPhrase": "freeform photos",
                        "c": "1480"
                }
        ],

        "totals":
        {
                "SearchPhrase": "",
                "c": "8873898"
        },

        "extremes":
        {
                "min":
                {
                        "SearchPhrase": "",
                        "c": "1480"
                },
                "max":
                {
                        "SearchPhrase": "",
                        "c": "8267016"
                }
        },

        "rows": 5,

        "rows_before_limit_at_least": 141137
}
```

The JSON is compatible with JavaScript. To ensure this, some characters are additionally escaped: the slash ` /`  is escaped as ` \/`; alternative line breaks ` U+2028` and ` U+2029`, which break some browsers, are escaped as ` \uXXXX`. ASCII control characters are escaped: backspace, form feed, line feed, carriage return, and horizontal tab are replaced with `\b`, `\f`, `\n`, `\r`, `\t`  , as well as the remaining bytes in the 00-1F range using `\uXXXX` sequences. Invalid UTF-8 sequences are changed to the replacement character � so the output text will consist of valid UTF-8 sequences. For compatibility with JavaScript, Int64 and UInt64 integers are enclosed in double quotes  by default. To remove the quotes, you can set the configuration parameter output_format_json_quote_64bit_integers to 0.

`rows` – The total number of output rows.

`rows_before_limit_at_least` The minimal number of rows there would have been without LIMIT. Output only if the query contains LIMIT.
If the query contains GROUP BY, rows_before_limit_at_least is the exact number of rows there would have been without a LIMIT.

`totals` – Total values (when using WITH TOTALS).

`extremes` – Extreme values (when extremes is set to 1).

This format is only appropriate for outputting a query result, but not for parsing (retrieving data to insert in a table).
See also the JSONEachRow format.