R/dbAppendTable_MariaDBConnection.R
, R/dbExistsTable_MariaDBConnection_character.R
, R/dbListObjects_MariaDBConnection_ANY.R
, and 6 more
mariadb-tables.Rd
These methods read or write entire tables from a MariaDB database.
# S4 method for MariaDBConnection
dbAppendTable(conn, name, value, ..., row.names = NULL)
# S4 method for MariaDBConnection,character
dbExistsTable(conn, name, ...)
# S4 method for MariaDBConnection
dbListObjects(conn, prefix = NULL, ...)
# S4 method for MariaDBConnection
dbListTables(conn, ...)
# S4 method for MariaDBConnection,character
dbReadTable(conn, name, ..., row.names = FALSE, check.names = TRUE)
# S4 method for MariaDBConnection,character
dbRemoveTable(conn, name, ..., temporary = FALSE, fail_if_missing = TRUE)
# S4 method for MariaDBConnection,character,character
dbWriteTable(
conn,
name,
value,
field.types = NULL,
overwrite = FALSE,
append = FALSE,
header = TRUE,
row.names = FALSE,
nrows = 50,
sep = ",",
eol = "\n",
skip = 0,
quote = "\"",
temporary = FALSE,
...
)
# S4 method for MariaDBConnection,character,data.frame
dbWriteTable(
conn,
name,
value,
field.types = NULL,
row.names = FALSE,
overwrite = FALSE,
append = FALSE,
...,
temporary = FALSE
)
a MariaDBConnection object, produced by
DBI::dbConnect()
a character string specifying a table name.
A data frame.
Unused, needed for compatibility with generic.
Either TRUE
, FALSE
, NA
or a string.
If TRUE
, always translate row names to a column called "row_names".
If FALSE
, never translate row names. If NA
, translate
rownames only if they're a character vector.
A string is equivalent to TRUE
, but allows you to override the
default name.
For backward compatibility, NULL
is equivalent to FALSE
.
A fully qualified path in the database's namespace, or NULL
.
This argument will be processed with dbUnquoteIdentifier()
.
If given the method will return all objects accessible through this prefix.
If TRUE
, the default, column names will be
converted to valid R identifiers.
If TRUE
, creates a temporary table that expires
when the connection is closed. For dbRemoveTable()
, only temporary
tables are considered if this argument is set to TRUE
.
If FALSE
, dbRemoveTable()
succeeds if the
table doesn't exist.
Optional, overrides default choices of field types, derived from the classes of the columns in the data frame.
a logical specifying whether to overwrite an existing table
or not. Its default is FALSE
.
a logical specifying whether to append to an existing table
in the DBMS. If appending, then the table (or temporary table)
must exist, otherwise an error is reported. Its default is FALSE
.
logical, does the input file have a header line? Default is the
same heuristic used by read.table()
, i.e., TRUE
if the first
line has one fewer column that the second line.
number of lines to rows to import using read.table
from
the input file to create the proper table definition. Default is 50.
field separator character
End-of-line separator
number of lines to skip before reading data in the input file.
the quote character used in the input file (defaults to
\"
.)
A data.frame in the case of dbReadTable()
; otherwise a logical
indicating whether the operation was successful.
When using load_data_local_infile = TRUE
in dbConnect()
,
pass safe = FALSE
to dbAppendTable()
to avoid transactions.
Because LOAD DATA INFILE
is used internally, this means that
rows violating primary key constraints are now silently ignored.
The data.frame returned by dbReadTable()
only has
primitive data, e.g., it does not coerce character data to factors.
Temporary tables are ignored for dbExistsTable()
and dbListTables()
due to
limitations of the underlying C API. For this reason, a prior existence check
is performed only before creating a regular persistent table; an attempt to
create a temporary table with an already existing name will fail with a
message from the database driver.
if (mariadbHasDefault()) {
con <- dbConnect(RMariaDB::MariaDB(), dbname = "test")
# By default, row names are written in a column to row_names, and
# automatically read back into the row.names()
dbWriteTable(con, "mtcars", mtcars[1:5, ], temporary = TRUE)
dbReadTable(con, "mtcars")
dbReadTable(con, "mtcars", row.names = FALSE)
}
#> mpg cyl disp hp drat wt qsec vs am gear carb
#> 1 21.0 6 160 110 3.90 2.620 16.46 0 1 4 4
#> 2 21.0 6 160 110 3.90 2.875 17.02 0 1 4 4
#> 3 22.8 4 108 93 3.85 2.320 18.61 1 1 4 1
#> 4 21.4 6 258 110 3.08 3.215 19.44 1 0 3 1
#> 5 18.7 8 360 175 3.15 3.440 17.02 0 0 3 2