CSVWithNamesAndTypes

CSVWithNamesAndTypes 格式文档

输入	输出	别名
✔	✔

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描述

还会输出两行表头，包含列名和类型，类似于 TabSeparatedWithNamesAndTypes。

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示例用法

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插入数据

从 version 23.1 开始，ClickHouse 在使用 CSV 格式时会自动检测 CSV 文件中的表头，因此无需使用 CSVWithNames 或 CSVWithNamesAndTypes。

使用以下名为 football_types.csv 的 CSV 文件：

date,season,home_team,away_team,home_team_goals,away_team_goals
Date,Int16,LowCardinality(String),LowCardinality(String),Int8,Int8
2022-04-30,2021,Sutton United,Bradford City,1,4
2022-04-30,2021,Swindon Town,Barrow,2,1
2022-04-30,2021,Tranmere Rovers,Oldham Athletic,2,0
2022-05-02,2021,Salford City,Mansfield Town,2,2
2022-05-02,2021,Port Vale,Newport County,1,2
2022-05-07,2021,Barrow,Northampton Town,1,3
2022-05-07,2021,Bradford City,Carlisle United,2,0
2022-05-07,2021,Bristol Rovers,Scunthorpe United,7,0
2022-05-07,2021,Exeter City,Port Vale,0,1
2022-05-07,2021,Harrogate Town A.F.C.,Sutton United,0,2
2022-05-07,2021,Hartlepool United,Colchester United,0,2
2022-05-07,2021,Leyton Orient,Tranmere Rovers,0,1
2022-05-07,2021,Mansfield Town,Forest Green Rovers,2,2
2022-05-07,2021,Newport County,Rochdale,0,2
2022-05-07,2021,Oldham Athletic,Crawley Town,3,3
2022-05-07,2021,Stevenage Borough,Salford City,4,2
2022-05-07,2021,Walsall,Swindon Town,0,3

创建表：

CREATE TABLE football
(
    `date` Date,
    `season` Int16,
    `home_team` LowCardinality(String),
    `away_team` LowCardinality(String),
    `home_team_goals` Int8,
    `away_team_goals` Int8
)
ENGINE = MergeTree
ORDER BY (date, home_team);

使用 CSVWithNamesAndTypes 格式插入数据：

INSERT INTO football FROM INFILE 'football_types.csv' FORMAT CSVWithNamesAndTypes;

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读取数据

使用 CSVWithNamesAndTypes 格式读取数据：

SELECT *
FROM football
FORMAT CSVWithNamesAndTypes

输出将是一个 CSV 文件，包含两行表头，分别表示列名和类型：

"date","season","home_team","away_team","home_team_goals","away_team_goals"
"Date","Int16","LowCardinality(String)","LowCardinality(String)","Int8","Int8"
"2022-04-30",2021,"Sutton United","Bradford City",1,4
"2022-04-30",2021,"Swindon Town","Barrow",2,1
"2022-04-30",2021,"Tranmere Rovers","Oldham Athletic",2,0
"2022-05-02",2021,"Port Vale","Newport County",1,2
"2022-05-02",2021,"Salford City","Mansfield Town",2,2
"2022-05-07",2021,"Barrow","Northampton Town",1,3
"2022-05-07",2021,"Bradford City","Carlisle United",2,0
"2022-05-07",2021,"Bristol Rovers","Scunthorpe United",7,0
"2022-05-07",2021,"Exeter City","Port Vale",0,1
"2022-05-07",2021,"Harrogate Town A.F.C.","Sutton United",0,2
"2022-05-07",2021,"Hartlepool United","Colchester United",0,2
"2022-05-07",2021,"Leyton Orient","Tranmere Rovers",0,1
"2022-05-07",2021,"Mansfield Town","Forest Green Rovers",2,2
"2022-05-07",2021,"Newport County","Rochdale",0,2
"2022-05-07",2021,"Oldham Athletic","Crawley Town",3,3
"2022-05-07",2021,"Stevenage Borough","Salford City",4,2
"2022-05-07",2021,"Walsall","Swindon Town",0,3

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格式设置

如果将设置 input_format_with_names_use_header 设为 1， 输入数据中的列会按名称映射到表中的列；如果将设置 input_format_skip_unknown_fields 设为 1，则会跳过名称未知的列。 否则，将跳过第一行。

如果将设置 input_format_with_types_use_header 设为 1， 输入数据中的类型会与表中对应列的类型进行比较。否则，将跳过第二行。