Returns if a table given by name exists in the database.
Methods in other packages
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")
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"')
- ...
Other parameters passed on to methods.
Value
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.
Failure modes
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 DBI::dbQuoteIdentifier()
or
if this results in a non-scalar.
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:
dbExistsTable()
will do the quoting, perhaps by callingdbQuoteIdentifier(conn, x = name)
If the result of a call to
DBI::dbQuoteIdentifier()
: no more quoting is done
For all tables listed by DBI::dbListTables()
, dbExistsTable()
returns TRUE
.
See also
Other DBIConnection generics:
DBIConnection-class
,
dbAppendTable()
,
dbAppendTableArrow()
,
dbCreateTable()
,
dbCreateTableArrow()
,
dbDataType()
,
dbDisconnect()
,
dbExecute()
,
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:")
dbExistsTable(con, "iris")
#> [1] FALSE
dbWriteTable(con, "iris", iris)
dbExistsTable(con, "iris")
#> [1] TRUE
dbDisconnect(con)