CSVWithNamesAndTypes

Documentação do formato CSVWithNamesAndTypes

Entrada	Saída	Alias
✔	✔

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Descrição

Também imprime duas linhas de cabeçalho com nomes de colunas e tipos, semelhante a TabSeparatedWithNamesAndTypes.

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Exemplo de uso

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Inserção de dados

A partir da versão 23.1, o ClickHouse detecta automaticamente cabeçalhos em arquivos CSV ao usar o formato CSV, portanto não é necessário usar CSVWithNames nem CSVWithNamesAndTypes.

Usando o arquivo CSV a seguir, chamado football_types.csv:

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

Crie uma tabela:

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);

Insira dados no formato CSVWithNamesAndTypes:

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

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Leitura de dados

Leia os dados usando o formato CSVWithNamesAndTypes:

SELECT *
FROM football
FORMAT CSVWithNamesAndTypes

A saída será um CSV com duas linhas de cabeçalho para os nomes e os tipos das colunas:

"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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Configurações de formato

Se a configuração input_format_with_names_use_header estiver definida como 1, as colunas dos dados de entrada serão mapeadas para as colunas da tabela com base em seus nomes, e colunas com nomes desconhecidos serão ignoradas se a configuração input_format_skip_unknown_fields estiver definida como 1. Caso contrário, a primeira linha será ignorada.

Se a configuração input_format_with_types_use_header estiver definida como 1, os tipos dos dados de entrada serão comparados com os tipos das colunas correspondentes da tabela. Caso contrário, a segunda linha será ignorada.