spec_sql_list_objects
Value
dbListObjects()
returns a data frame
with columns
table
and is_prefix
(in that order),
optionally with other columns with a dot (.
) prefix.
The table
column is of type list.
Each object in this list is suitable for use as argument in DBI::dbQuoteIdentifier()
.
The is_prefix
column is a logical.
This data frame contains one row for each object (schema, table
and view)
accessible from the prefix (if passed) or from the global namespace
(if prefix is omitted).
Tables added with DBI::dbWriteTable()
are
part of the data frame.
As soon a table is removed from the database,
it is also removed from the data frame of database objects.
The same applies to temporary objects if supported by the database.
The returned names are suitable for quoting with dbQuoteIdentifier()
.
Specification
The prefix
column indicates if the table
value refers to a table
or a prefix.
For a call with the default prefix = NULL
, the table
values that have is_prefix == FALSE
correspond to the tables
returned from DBI::dbListTables()
,
The table
object can be quoted with DBI::dbQuoteIdentifier()
.
The result of quoting can be passed to DBI::dbUnquoteIdentifier()
.
(For backends it may be convenient to use the DBI::Id class, but this is
not required.)
Values in table
column that have is_prefix == TRUE
can be
passed as the prefix
argument to another call to dbListObjects()
.
For the data frame returned from a dbListObject()
call with the
prefix
argument set, all table
values where is_prefix
is
FALSE
can be used in a call to DBI::dbExistsTable()
which returns
TRUE
.
See also
Other sql specifications:
spec_sql_append_table
,
spec_sql_create_table
,
spec_sql_exists_table
,
spec_sql_list_fields
,
spec_sql_list_tables
,
spec_sql_quote_identifier
,
spec_sql_quote_literal
,
spec_sql_quote_string
,
spec_sql_read_table
,
spec_sql_remove_table
,
spec_sql_unquote_identifier
,
spec_sql_write_table