> ## Documentation Index
> Fetch the complete documentation index at: https://clickhouse.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# format_csv_* 格式设置

> ClickHouse 在 format_csv_* 生成分组中的格式设置。

export const SettingsInfoBlock = ({type, default_value, changeable_without_restart}) => {
  return <div className="not-prose" style={{
    display: "flex",
    flexWrap: "wrap",
    alignItems: "baseline",
    columnGap: "0.5rem",
    rowGap: "0.125rem",
    margin: "0.375rem 0",
    fontSize: "0.8125rem",
    lineHeight: "1.125rem"
  }}>
      <div style={{
    fontWeight: 600,
    opacity: 0.72
  }}>类型</div>
      <div style={{
    overflowWrap: "anywhere"
  }}>{type}</div>
      <div style={{
    fontWeight: 600,
    opacity: 0.72,
    marginInlineStart: "0.5rem"
  }}>默认值</div>
      <div style={{
    overflowWrap: "anywhere"
  }}>{default_value}</div>
      {changeable_without_restart && <div style={{
    fontWeight: 600,
    opacity: 0.72,
    marginInlineStart: "0.5rem"
  }}>
          无需重启即可更改
        </div>}
      {changeable_without_restart && <div style={{
    overflowWrap: "anywhere"
  }}>
          {changeable_without_restart}
        </div>}
    </div>;
};

这些设置是根据[source](https://github.com/ClickHouse/ClickHouse/blob/master/src/Core/FormatFactorySettings.h)自动生成的。

<div id="format_csv_allow_double_quotes">
  ## format\_csv\_allow\_double\_quotes
</div>

<SettingsInfoBlock type="Bool" default_value="1" />

如果设置为 true，则允许字符串使用双引号括起。

<div id="format_csv_allow_single_quotes">
  ## format\_csv\_allow\_single\_quotes
</div>

<SettingsInfoBlock type="Bool" default_value="0" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "22.7"},{"label": "0"},{"label": "大多数工具不会将 CSV 中的单引号作特殊处理，因此默认也不应这样处理"}]}]} />

如果设置为 true，则允许使用单引号括起来的字符串。

<div id="format_csv_delimiter">
  ## format\_csv\_delimiter
</div>

<SettingsInfoBlock type="Char" default_value="," />

CSV 数据中用作分隔符的字符。如果将其设置为字符串，该字符串的长度必须为 1。

<div id="format_csv_null_representation">
  ## format\_csv\_null\_representation
</div>

<SettingsInfoBlock type="String" default_value="\N" />

CSV 格式中的自定义 NULL 表示