dbGetRowCount: The number of rows fetched so far

In DBI: R Database Interface

The number of rows fetched so far

Description

Returns the total number of rows actually fetched with calls to dbFetch() for this result set.

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

Usage

dbGetRowCount(res, ...)

Arguments

res	An object inheriting from DBIResult.
...	Other arguments passed on to methods.

Value

dbGetRowCount() returns a scalar number (integer or numeric), the number of rows fetched so far. After calling dbSendQuery(), the row count is initially zero. After a call to dbFetch() without limit, the row count matches the total number of rows returned. Fetching a limited number of rows increases the number of rows by the number of rows returned, even if fetching past the end of the result set. For queries with an empty result set, zero is returned even after fetching. For data manipulation statements issued with dbSendStatement(), zero is returned before and after calling dbFetch().

Failure modes

Attempting to get the row count for a result set cleared with dbClearResult() gives an error.

See Also

Other DBIResult generics: DBIResult-class, dbBind(), dbClearResult(), dbColumnInfo(), dbFetch(), dbGetInfo(), dbGetRowsAffected(), dbGetStatement(), dbHasCompleted(), dbIsReadOnly(), dbIsValid(), dbQuoteLiteral(), dbQuoteString()

Examples

con <- dbConnect(RSQLite::SQLite(), ":memory:")

dbWriteTable(con, "mtcars", mtcars)
rs <- dbSendQuery(con, "SELECT * FROM mtcars")

dbGetRowCount(rs)
ret1 <- dbFetch(rs, 10)
dbGetRowCount(rs)
ret2 <- dbFetch(rs)
dbGetRowCount(rs)
nrow(ret1) + nrow(ret2)

dbClearResult(rs)
dbDisconnect(con)

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