This method returns if the operation has completed. A SELECT query is completed if all rows have been fetched. A data manipulation statement is always completed.

dbHasCompleted(res, ...)

Arguments

res

An object inheriting from DBIResult.

...

Other arguments passed on to methods.

Value

dbHasCompleted() returns a logical scalar. For a query initiated by dbSendQuery() with non-empty result set, dbHasCompleted() returns FALSE initially and TRUE after calling dbFetch() without limit. For a query initiated by dbSendStatement(), dbHasCompleted() always returns TRUE. Attempting to query completion status for a result set cleared with dbClearResult() gives an error.

Specification

The completion status for a query is only guaranteed to be set to FALSE after attempting to fetch past the end of the entire result. Therefore, for a query with an empty result set, the initial return value is unspecified, but the result value is TRUE after trying to fetch only one row. Similarly, for a query with a result set of length n, the return value is unspecified after fetching n rows, but the result value is TRUE after trying to fetch only one more row.

See also

Other DBIResult generics: DBIResult-class, dbBind, dbClearResult, dbColumnInfo, dbFetch, dbGetInfo, dbGetRowCount, dbGetRowsAffected, dbGetStatement, dbIsValid, dbQuoteIdentifier, dbQuoteString

Examples

con <- dbConnect(RSQLite::SQLite(), ":memory:") dbWriteTable(con, "mtcars", mtcars) rs <- dbSendQuery(con, "SELECT * FROM mtcars") dbHasCompleted(rs)
#> [1] FALSE
ret1 <- dbFetch(rs, 10) dbHasCompleted(rs)
#> [1] FALSE
ret2 <- dbFetch(rs) dbHasCompleted(rs)
#> [1] TRUE