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86 lines
3.2 KiB
ReStructuredText
86 lines
3.2 KiB
ReStructuredText
JSON
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-----
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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:
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.. code-block:: sql
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SELECT SearchPhrase, count() AS c FROM test.hits GROUP BY SearchPhrase WITH TOTALS ORDER BY c DESC LIMIT 5 FORMAT JSON
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{
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"meta":
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[
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{
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"name": "SearchPhrase",
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"type": "String"
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},
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{
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"name": "c",
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"type": "UInt64"
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}
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],
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"data":
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[
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{
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"SearchPhrase": "",
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"c": "8267016"
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},
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{
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"SearchPhrase": "интерьер ванной комнаты",
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"c": "2166"
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},
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{
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"SearchPhrase": "яндекс",
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"c": "1655"
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},
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{
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"SearchPhrase": "весна 2014 мода",
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"c": "1549"
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},
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{
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"SearchPhrase": "фриформ фото",
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"c": "1480"
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}
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],
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"totals":
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{
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"SearchPhrase": "",
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"c": "8873898"
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},
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"extremes":
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{
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"min":
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{
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"SearchPhrase": "",
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"c": "1480"
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},
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"max":
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{
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"SearchPhrase": "",
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"c": "8267016"
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}
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},
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"rows": 5,
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"rows_before_limit_at_least": 141137
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}
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JSON is compatible with JavaScript. For this purpose, certain symbols are additionally escaped: the forward slash ``/`` is escaped as ``\/``; alternative line breaks ``U+2028`` and ``U+2029``, which don't work in some browsers, are escaped as \uXXXX-sequences. ASCII control characters are escaped: backspace, form feed, line feed, carriage return, and horizontal tab as ``\b``, ``\f``, ``\n``, ``\r``, and ``\t`` respectively, along with the rest of the bytes from the range 00-1F using \uXXXX-sequences. Invalid UTF-8 sequences are changed to the replacement character ``<EFBFBD>`` and, thus, the output text will consist of valid UTF-8 sequences. UInt64 and Int64 numbers are output in double quotes for compatibility with JavaScript.
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``rows`` - The total number of output rows.
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``rows_before_limit_at_least`` - The minimal number of rows there would have been without a LIMIT. Output only if the query contains LIMIT.
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If the query contains GROUP BY, ``rows_before_limit_at_least`` is the exact number of rows there would have been without a LIMIT.
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``totals`` - Total values (when using WITH TOTALS).
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``extremes`` - Extreme values (when extremes is set to 1).
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This format is only appropriate for outputting a query result, not for parsing.
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See JSONEachRow format for INSERT queries.
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