> ## Documentation Index
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> Use this file to discover all available pages before exploring further.

> JSONCompactColumns 格式文档

# JSONCompactColumns

| 输入 | 输出 | 别名 |
| -- | -- | -- |
| ✔  | ✔  |    |

<div id="description">
  ## 说明
</div>

在这种格式下，所有数据都表示为一个 JSON 数组。

<Note>
  `JSONCompactColumns` 输出格式会将所有数据缓存在内存中，并以单个块的形式输出，因此可能导致较高的内存占用。
</Note>

<div id="example-usage">
  ## 使用示例
</div>

<div id="inserting-data">
  ### 插入数据
</div>

使用一个名为 `football.json`、包含以下数据的 JSON 文件：

```json theme={null}
[
    ["2022-04-30", "2022-04-30", "2022-04-30", "2022-05-02", "2022-05-02", "2022-05-07", "2022-05-07", "2022-05-07", "2022-05-07", "2022-05-07", "2022-05-07", "2022-05-07", "2022-05-07", "2022-05-07", "2022-05-07", "2022-05-07", "2022-05-07"],
    [2021, 2021, 2021, 2021, 2021, 2021, 2021, 2021, 2021, 2021, 2021, 2021, 2021, 2021, 2021, 2021, 2021],
    ["Sutton United", "Swindon Town", "Tranmere Rovers", "Port Vale", "Salford City", "Barrow", "Bradford City", "Bristol Rovers", "Exeter City", "Harrogate Town A.F.C.", "Hartlepool United", "Leyton Orient", "Mansfield Town", "Newport County", "Oldham Athletic", "Stevenage Borough", "Walsall"],
    ["Bradford City", "Barrow", "Oldham Athletic", "Newport County", "Mansfield Town", "Northampton Town", "Carlisle United", "Scunthorpe United", "Port Vale", "Sutton United", "Colchester United", "Tranmere Rovers", "Forest Green Rovers", "Rochdale", "Crawley Town", "Salford City", "Swindon Town"],
    [1, 2, 2, 1, 2, 1, 2, 7, 0, 0, 0, 0, 2, 0, 3, 4, 0],
    [4, 1, 0, 2, 2, 3, 0, 0, 1, 2, 2, 1, 2, 2, 3, 2, 3]
]
```

插入数据：

```sql theme={null}
INSERT INTO football FROM INFILE 'football.json' FORMAT JSONCompactColumns;
```

<div id="reading-data">
  ### 读取数据
</div>

使用 `JSONCompactColumns` 格式来读取数据：

```sql theme={null}
SELECT *
FROM football
FORMAT JSONCompactColumns
```

输出将采用 JSON 格式：

```json theme={null}
[
    ["2022-04-30", "2022-04-30", "2022-04-30", "2022-05-02", "2022-05-02", "2022-05-07", "2022-05-07", "2022-05-07", "2022-05-07", "2022-05-07", "2022-05-07", "2022-05-07", "2022-05-07", "2022-05-07", "2022-05-07", "2022-05-07", "2022-05-07"],
    [2021, 2021, 2021, 2021, 2021, 2021, 2021, 2021, 2021, 2021, 2021, 2021, 2021, 2021, 2021, 2021, 2021],
    ["Sutton United", "Swindon Town", "Tranmere Rovers", "Port Vale", "Salford City", "Barrow", "Bradford City", "Bristol Rovers", "Exeter City", "Harrogate Town A.F.C.", "Hartlepool United", "Leyton Orient", "Mansfield Town", "Newport County", "Oldham Athletic", "Stevenage Borough", "Walsall"],
    ["Bradford City", "Barrow", "Oldham Athletic", "Newport County", "Mansfield Town", "Northampton Town", "Carlisle United", "Scunthorpe United", "Port Vale", "Sutton United", "Colchester United", "Tranmere Rovers", "Forest Green Rovers", "Rochdale", "Crawley Town", "Salford City", "Swindon Town"],
    [1, 2, 2, 1, 2, 1, 2, 7, 0, 0, 0, 0, 2, 0, 3, 4, 0],
    [4, 1, 0, 2, 2, 3, 0, 0, 1, 2, 2, 1, 2, 2, 3, 2, 3]
]
```

块中不存在的列将使用默认值进行填充 (此处可以使用 [`input_format_defaults_for_omitted_fields`](/zh/reference/settings/formats#input_format_defaults_for_omitted_fields) 设置)

<div id="format-settings">
  ## 格式设置
</div>