import_flobs: Import flobs.

In dbflobr: Read and Write Files to SQLite Databases

Import flobs.

Description

Import flobs to SQLite database column from directory. Values in file name are matched to table primary key to determine where to write flob.

Usage

import_flobs(
  column_name,
  table_name,
  conn,
  dir = ".",
  sep = "_-_",
  pattern = ".*",
  sub = FALSE,
  exists = FALSE,
  recursive = FALSE,
  replace = FALSE
)

Arguments

column_name	A string of the name of the BLOB column.
table_name	A string of the name of the existing table.
conn	A SQLite connection object.
dir	A string of the path to the directory to import files from.
sep	A string of the separator between values in file names.
pattern	A regular expression specifying the pattern file names must match.
sub	A logical scalar specifying whether to import flobs based on their filename (sub = FALSE) or the name of their subdirectory (sub = TRUE) which must only contain 1 file. If sub = NA and replace = TRUE then the names of the subdirectories are used irrespective of whether they include files and existing flobs are deleted if the corresponding subdirectory is empty. If sub = TRUE or sub = NA then recursion is just one subfolder deep.
exists	A logical scalar specifying whether the column must (TRUE) or mustn't (FALSE) already exist or whether it doesn't matter (NA). IF FALSE, a new BLOB column is created.
recursive	A flag indicating whether to recurse into file directory (TRUE) or not (FALSE).
replace	A flag indicating whether to replace existing flobs (TRUE) or not (FALSE).

Value

An invisible named vector indicating file name and whether the file was successfully written to database.

Examples

conn <- DBI::dbConnect(RSQLite::SQLite(), ":memory:")
DBI::dbGetQuery(conn, "CREATE TABLE Table1 (CharColumn TEXT PRIMARY KEY NOT NULL)")
DBI::dbWriteTable(conn, "Table1", data.frame(CharColumn = c("a", "b")), append = TRUE)
key <- data.frame(CharColumn = "a", stringsAsFactors = FALSE)[0,,drop = FALSE]
dir <- tempdir()
write.csv(key, file.path(dir, "a.csv"))
import_flobs("BlobColumn", "Table1", conn, dir)
DBI::dbDisconnect(conn)

dbflobr documentation built on Aug. 20, 2022, 1:06 a.m.