Returns if a table given by name exists in the database.
This documentation page describes the generics. Refer to the documentation pages linked below for the documentation for the methods that are implemented in various backend packages.
DatabaseConnector::dbExistsTable("DatabaseConnectorConnection", "character")
RPostgreSQL::dbExistsTable("PostgreSQLConnection", "character")
sparklyr::dbExistsTable("spark_connection", "character")
dbExistsTable(conn, name, ...)
A DBIConnection object, as returned by
dbConnect()
.
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"')
Other parameters passed on to methods.
dbExistsTable()
returns a logical scalar, TRUE
if the table or view
specified by the name
argument exists, FALSE
otherwise.
This includes temporary tables if supported by the database.
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.
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: dbExistsTable()
will do the
quoting,
perhaps by calling dbQuoteIdentifier(conn, x = name)
If the result of a call to dbQuoteIdentifier()
: no more quoting is done
For all tables listed by dbListTables()
, dbExistsTable()
returns TRUE
.
Other DBIConnection generics:
DBIConnection-class
,
dbAppendTable()
,
dbCreateTable()
,
dbDataType()
,
dbDisconnect()
,
dbExecute()
,
dbGetException()
,
dbGetInfo()
,
dbGetQuery()
,
dbIsReadOnly()
,
dbIsValid()
,
dbListFields()
,
dbListObjects()
,
dbListResults()
,
dbListTables()
,
dbReadTable()
,
dbRemoveTable()
,
dbSendQuery()
,
dbSendStatement()
,
dbWriteTable()
con <- dbConnect(RSQLite::SQLite(), ":memory:")
dbExistsTable(con, "iris")
#> [1] FALSE
dbWriteTable(con, "iris", iris)
dbExistsTable(con, "iris")
#> [1] TRUE
dbDisconnect(con)