mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-10-20 23:41:01 +00:00
Symbolic link
3.1 KiB
Symbolic link
3.1 KiB
IPv4
IPv4
是基于 UInt32
的domain类型,用来存储IPv4地址。它使用紧凑的存储方式,提供用户友好的输入输出格式,
自动检查列类型。
基本使用
CREATE TABLE hits (url String, from IPv4) ENGINE = MergeTree() ORDER BY url;
DESCRIBE TABLE hits;
┌─name─┬─type───┬─default_type─┬─default_expression─┬─comment─┬─codec_expression─┐
│ url │ String │ │ │ │ │
│ from │ IPv4 │ │ │ │ │
└──────┴────────┴──────────────┴────────────────────┴─────────┴──────────────────┘
您也可以使用IPv4 domain作主键:
CREATE TABLE hits (url String, from IPv4) ENGINE = MergeTree() ORDER BY from;
IPv4
domain支持定制化的IPv4地址字符串格式:
INSERT INTO hits (url, from) VALUES ('https://wikipedia.org', '116.253.40.133')('https://clickhouse.yandex', '183.247.232.58')('https://clickhouse.yandex/docs/en/', '116.106.34.242');
SELECT * FROM hits;
┌─url────────────────────────────────┬───────────from─┐
│ https://clickhouse.yandex/docs/en/ │ 116.106.34.242 │
│ https://wikipedia.org │ 116.253.40.133 │
│ https://clickhouse.yandex │ 183.247.232.58 │
└────────────────────────────────────┴────────────────┘
数据值以紧凑的二进制格式存储:
SELECT toTypeName(from), hex(from) FROM hits LIMIT 1;
┌─toTypeName(from)─┬─hex(from)─┐
│ IPv4 │ B7F7E83A │
└──────────────────┴───────────┘
Domain不可隐式转换为除UInt32
以外的类型。如果要将IPv4值转换为字符串,则必须使用IPv4NumToString()
函数显示的进行此操作。
SELECT toTypeName(s), IPv4NumToString(from) as s FROM hits LIMIT 1;
┌─toTypeName(IPv4NumToString(from))─┬─s──────────────┐
│ String │ 183.247.232.58 │
└───────────────────────────────────┴────────────────┘
或转换为 UInt32
类型:
SELECT toTypeName(i), CAST(from as UInt32) as i FROM hits LIMIT 1;
┌─toTypeName(CAST(from, 'UInt32'))─┬──────────i─┐
│ UInt32 │ 3086477370 │
└──────────────────────────────────┴────────────┘