Frage 1: Mit `dbWriteTable` wird eine Tabelle aus der Datenbank erstellt. Ist diese Behauptung richtig?
Die csv-Dateien haben das folgende Format:
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$ file -i 1.csv
1.csv: application/csv; charset=us-ascii
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data/
└── TEST
├── 2022
│ ├── 1.csv
│ ├── 2.csv
│ └── 3.csv
└── TEST-2022.csv <- The file TEST-2022.csv are the three csv files in one file.
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# Add libraries
library(duckdb)
library(dplyr)
library(DBI)
path <- "data/TEST/2022"
setwd(path)
# write to disk as "test-year.duckdb", other defaults to in memory
con <- DBI::dbConnect(duckdb::duckdb(), dbdir = "test-2022.duckdb")
duckdb::duckdb_read_csv(
conn = con, name = "test_csv", files = "TEST-2022.csv",
header = TRUE, delim = ",", encoding = "UTF-8"
)
dbDisconnect(con, shutdown = TRUE)
dbWriteTable(con, "test-2022_table", "test-2022")
res <- dbGetQuery(con, 'SELECT * FROM "test-2022"')
print(res)
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>
>
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DateTime,Beta,Alpha
01/02/2022 22:03:13.151,0.83987,0.84129
01/02/2022 22:05:03.942,0.83959,0.84143
01/02/2022 22:05:09.121,0.83982,0.84124
01/02/2022 22:05:09.286,0.83978,0.8412
01/02/2022 22:06:04.904,0.83981,0.84123
01/02/2022 22:06:04.909,0.83979,0.84121
01/02/2022 22:06:08.360,0.8398,0.84122
01/02/2022 22:06:51.568,0.8398,0.84111
01/02/2022 22:06:51.573,0.83959,0.841
01/02/2022 22:06:53.234,0.83958,0.841
01/02/2022 22:06:57.617,0.83958,0.84099
01/02/2022 22:06:59.648,0.83957,0.84099
01/02/2022 22:07:00.037,0.83958,0.84099
01/02/2022 22:07:00.378,0.83959,0.84099
01/02/2022 22:07:13.989,0.8396,0.84099
01/02/2022 22:07:14.071,0.83961,0.84099
01/02/2022 22:07:15.506,0.83962,0.84099
01/02/2022 22:07:15.839,0.83962,0.841
01/02/2022 22:07:16.219,0.83963,0.841
01/02/2022 22:07:16.835,0.83962,0.841
01/02/2022 22:07:17.185,0.83963,0.841
01/02/2022 22:07:17.214,0.83963,0.84099
01/02/2022 22:07:17.517,0.83962,0.84099
01/02/2022 22:07:19.701,0.83961,0.84099
01/02/2022 22:07:20.477,0.83962,0.84099
01/02/2022 22:07:21.478,0.83961,0.84099
01/02/2022 22:07:22.340,0.83962,0.84099
01/02/2022 22:07:23.344,0.83961,0.84099
01/02/2022 22:07:27.841,0.83962,0.84099
01/02/2022 22:07:28.589,0.83963,0.84099
01/02/2022 22:07:28.734,0.83964,0.84099
01/02/2022 22:07:29.076,0.83965,0.84099
01/02/2022 22:07:34.188,0.83966,0.84099
01/02/2022 22:07:34.528,0.83967,0.84099
01/02/2022 22:07:34.873,0.83966,0.84099
01/02/2022 22:07:35.969,0.83967,0.84099
01/02/2022 22:07:38.535,0.83968,0.84099