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[Experimental]

Reads a database table as an Arrow object. Use dbReadTable() instead to obtain a data frame.

Usage

dbReadTableArrow(conn, name, ...)

Arguments

conn

A DBIConnection object, as returned by dbConnect().

name

The table name, passed on to dbQuoteIdentifier(). Options are:

  • a character string with the unquoted DBMS table name, e.g. "table_name",

  • a call to Id() with components to the fully qualified table name, e.g. Id(schema = "my_schema", table = "table_name")

  • a call to SQL() with the quoted and fully qualified table name given verbatim, e.g. SQL('"my_schema"."table_name"')

...

Other parameters passed on to methods.

Value

dbReadTableArrow() returns an Arrow object that contains the complete data from the remote table, effectively the result of calling dbGetQueryArrow() with SELECT * FROM <name>.

An empty table is returned as an Arrow object with zero rows.

Details

This function returns an Arrow object. Convert it to a data frame with as.data.frame() or use dbReadTable() to obtain a data frame.

Failure modes

An error is raised if the table does not exist.

An error is raised when calling this method for a closed or invalid connection. An error is raised if name cannot be processed with dbQuoteIdentifier() or if this results in a non-scalar.

Specification

The name argument is processed as follows, to support databases that allow non-syntactic names for their objects:

  • If an unquoted table name as string: dbReadTableArrow() will do the quoting, perhaps by calling dbQuoteIdentifier(conn, x = name)

  • If the result of a call to dbQuoteIdentifier(): no more quoting is done

Examples

# Read data as Arrow table
con <- dbConnect(RSQLite::SQLite(), ":memory:")

dbWriteTable(con, "mtcars", mtcars[1:10, ])
dbReadTableArrow(con, "mtcars")
#> <nanoarrow_array_stream struct<mpg: double, cyl: double, disp: double, hp: double, drat: double, wt: double, qsec: double, vs: double, am: double, gear: double, carb: double>>
#>  $ get_schema:function ()  
#>  $ get_next  :function (schema = x$get_schema(), validate = TRUE)  
#>  $ release   :function ()  

dbDisconnect(con)