dbWriteTable() executes several SQL statements that create/overwrite a table and fill it with values. RPostgres does not use parameterised queries to insert rows because benchmarks revealed that this was considerably slower than using a single SQL string.

dbAppendTable() is overridden because RPostgres uses placeholders of the form $1, $2 etc. instead of ?.

# S4 method for PqConnection,character,data.frame
dbWriteTable(
  conn,
  name,
  value,
  ...,
  row.names = FALSE,
  overwrite = FALSE,
  append = FALSE,
  field.types = NULL,
  temporary = FALSE,
  copy = TRUE
)

# S4 method for PqConnection
sqlData(con, value, row.names = FALSE, ...)

# S4 method for PqConnection
dbAppendTable(conn, name, value, ..., row.names = NULL)

# S4 method for PqConnection,character
dbReadTable(conn, name, ..., check.names = TRUE, row.names = FALSE)

# S4 method for PqConnection
dbListTables(conn, ...)

# S4 method for PqConnection,character
dbExistsTable(conn, name, ...)

# S4 method for PqConnection,Id
dbExistsTable(conn, name, ...)

# S4 method for PqConnection,character
dbRemoveTable(conn, name, ..., temporary = FALSE, fail_if_missing = TRUE)

# S4 method for PqConnection,character
dbListFields(conn, name, ...)

# S4 method for PqConnection,Id
dbListFields(conn, name, ...)

# S4 method for PqConnection
dbListObjects(conn, prefix = NULL, ...)

Arguments

conn

a PqConnection object, produced by DBI::dbConnect()

name

a character string specifying a table name. Names will be automatically quoted so you can use any sequence of characters, not just any valid bare table name.

value

A data.frame to write to the database.

...

Ignored.

row.names

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.

overwrite

a logical specifying whether to overwrite an existing table or not. Its default is FALSE.

append

a logical specifying whether to append to an existing table in the DBMS. Its default is FALSE.

field.types

character vector of named SQL field types where the names are the names of new table's columns. If missing, types inferred with DBI::dbDataType()).

temporary

If TRUE, only temporary tables are considered.

copy

If TRUE, serializes the data frame to a single string and uses COPY name FROM stdin. This is fast, but not supported by all postgres servers (e.g. Amazon's Redshift). If FALSE, generates a single SQL string. This is slower, but always supported.

con

A database connection.

check.names

If TRUE, the default, column names will be converted to valid R identifiers.

fail_if_missing

If FALSE, dbRemoveTable() succeeds if the table doesn't exist.

prefix

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.

Examples

# For running the examples on systems without PostgreSQL connection: run <- postgresHasDefault()
#> Could not initialise default postgres database. If postgres is running #> check that the environment variables PGHOST, PGPORT, #> PGUSER, PGPASSWORD, and PGDATABASE, are defined and #> point to your database.
library(DBI) if (run) con <- dbConnect(RPostgres::Postgres()) if (run) dbListTables(con) if (run) dbWriteTable(con, "mtcars", mtcars, temporary = TRUE) if (run) dbReadTable(con, "mtcars") if (run) dbListTables(con) if (run) dbExistsTable(con, "mtcars") # A zero row data frame just creates a table definition. if (run) dbWriteTable(con, "mtcars2", mtcars[0, ], temporary = TRUE) if (run) dbReadTable(con, "mtcars2") if (run) dbDisconnect(con)