dbCreateTable: Create a table in the database

In DBI: R Database Interface

Create a table in the database

Description

The default dbCreateTable() method calls sqlCreateTable() and dbExecute(). Use dbCreateTableArrow() to create a table from an Arrow schema.

\Sexpr[results=rd,stage=render]{DBI:::methods_as_rd("dbCreateTable")}

Usage

dbCreateTable(conn, name, fields, ..., row.names = NULL, temporary = FALSE)

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"')
fields	Either a character vector or a data frame. A named character vector: Names are column names, values are types. Names are escaped with dbQuoteIdentifier(). Field types are unescaped. A data frame: field types are generated using dbDataType().
...	Other parameters passed on to methods.
row.names	Must be NULL.
temporary	If TRUE, will generate a temporary table.

Details

Backends compliant to ANSI SQL 99 don't need to override it. Backends with a different SQL syntax can override sqlCreateTable(), backends with entirely different ways to create tables need to override this method.

The row.names argument is not supported by this method. Process the values with sqlRownamesToColumn() before calling this method.

The argument order is different from the sqlCreateTable() method, the latter will be adapted in a later release of DBI.

Value

dbCreateTable() returns TRUE, invisibly.

Failure modes

If the table exists, an error is raised; the remote table remains unchanged.

An error is raised when calling this method for a closed or invalid connection. An error is also raised if name cannot be processed with dbQuoteIdentifier() or if this results in a non-scalar. Invalid values for the row.names and temporary arguments (non-scalars, unsupported data types, NA, incompatible values, duplicate names) also raise an error.

Additional arguments

The following arguments are not part of the dbCreateTable() generic (to improve compatibility across backends) but are part of the DBI specification:

• temporary (default: FALSE)

They must be provided as named arguments. See the "Specification" and "Value" sections for details on their usage.

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: dbCreateTable() will do the quoting, perhaps by calling dbQuoteIdentifier(conn, x = name)

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

The value argument can be:

• a data frame,

• a named list of SQL types

If the temporary argument is TRUE, the table is not available in a second connection and is gone after reconnecting. Not all backends support this argument. A regular, non-temporary table is visible in a second connection, in a pre-existing connection, and after reconnecting to the database.

SQL keywords can be used freely in table names, column names, and data. Quotes, commas, and spaces can also be used for table names and column names, if the database supports non-syntactic identifiers.

The row.names argument must be missing or NULL, the default value. All other values for the row.names argument (in particular TRUE, NA, and a string) raise an error.

See Also

Other DBIConnection generics: DBIConnection-class, dbAppendTable(), dbAppendTableArrow(), dbCreateTableArrow(), dbDataType(), dbDisconnect(), dbExecute(), dbExistsTable(), dbGetException(), dbGetInfo(), dbGetQuery(), dbGetQueryArrow(), dbIsReadOnly(), dbIsValid(), dbListFields(), dbListObjects(), dbListResults(), dbListTables(), dbQuoteIdentifier(), dbReadTable(), dbReadTableArrow(), dbRemoveTable(), dbSendQuery(), dbSendQueryArrow(), dbSendStatement(), dbUnquoteIdentifier(), dbWriteTable(), dbWriteTableArrow()

Examples

con <- dbConnect(RSQLite::SQLite(), ":memory:")
dbCreateTable(con, "iris", iris)
dbReadTable(con, "iris")
dbDisconnect(con)

DBI documentation built on June 22, 2024, 9:41 a.m.