DuckDB connection class — duckdb_connection-class • duckdb

Usage

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

# S4 method for class 'duckdb_connection'
dbBegin(conn, ...)

# S4 method for class 'duckdb_connection'
dbCommit(conn, ...)

# S4 method for class 'duckdb_connection'
dbDataType(dbObj, obj, ...)

# S4 method for class 'duckdb_connection,ANY'
dbExistsTable(conn, name, ...)

# S4 method for class 'duckdb_connection'
dbGetInfo(dbObj, ...)

# S4 method for class 'duckdb_connection'
dbIsValid(dbObj, ...)

# S4 method for class 'duckdb_connection,Id'
dbListFields(conn, name, ...)

# S4 method for class 'duckdb_connection,character'
dbListFields(conn, name, ...)

# S4 method for class 'duckdb_connection'
dbListTables(conn, ...)

# S4 method for class 'duckdb_connection,ANY'
dbQuoteIdentifier(conn, x, ...)

# S4 method for class 'duckdb_connection'
dbQuoteLiteral(conn, x, ...)

# S4 method for class 'duckdb_connection,character'
dbRemoveTable(conn, name, ..., fail_if_missing = TRUE)

# S4 method for class 'duckdb_connection'
dbRollback(conn, ...)

# S4 method for class 'duckdb_connection,character'
dbSendQueryArrow(conn, statement, params = NULL, ...)

# S4 method for class 'duckdb_connection,character'
dbSendQuery(conn, statement, params = NULL, ..., arrow = FALSE)

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

# S4 method for class 'duckdb_connection'
show(object)

Arguments

conn

A duckdb_connection object as returned by DBI::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"')

value

A data.frame (or coercible to data.frame).

...

Other parameters passed on to methods.

row.names

Whether the row.names of the data.frame should be preserved

dbObj

An object inheriting from class duckdb_connection.

obj

An R object whose SQL type we want to determine.

statement

a character string containing SQL.

params

For dbBind(), a list of values, named or unnamed, or a data frame, with one element/column per query parameter. For dbBindArrow(), values as a nanoarrow stream, with one column per query parameter.

arrow

Whether the query should be returned as an Arrow Table

overwrite

If a table with the given name already exists, should it be overwritten?

append

If a table with the given name already exists, just try to append the passed data to it

field.types

Override the auto-generated SQL types

temporary

Should the created table be temporary?

object

Any R object

Slots

conn_ref: external pointer to the underlying DuckDB connection.
driver: the duckdb_driver this connection was opened from.
debug: whether debug information (such as queries) is printed.
convert_opts: internal options controlling how result values are converted to R.
reserved_words: character vector of the engine's reserved SQL keywords, used to quote identifiers.
timezone_out: time zone results are returned in; superseded by convert_opts, from which it is copied at construction, and no longer read internally.
tz_out_convert: how timestamps are converted to timezone_out ("with" or "force"); superseded by convert_opts.
bigint: how 64-bit integers are returned; superseded by convert_opts.

Multiple statements

A statement can hold several SQL statements separated by semicolons, in dbSendQuery(), dbSendQueryArrow(), and the helpers built on them, such as dbExecute() and dbGetQuery(). They run in order, and each is prepared only after those before it have run, so it sees their effects: a PRAGMA that generates SQL, such as create_fts_index, finds a table created earlier in the same string. Every statement but the last runs when the query is sent, params bind to the last statement only, and only the last statement's result is returned.

The whole string is parsed before anything runs, so a syntax error in any statement means that none of them run. Any other error stops at the statement that raised it, and the statements before it keep their effect, because the string does not run in a transaction of its own. For all or nothing, run the call inside dbWithTransaction(), or call dbBegin() before it and dbRollback() if it fails. To know which statements have run when one fails, send one statement per call.