Description Usage Arguments See Also Examples
By default, SQLite is in auto-commit mode. dbBegin()
starts
a SQLite transaction and turns auto-commit off. dbCommit()
and
dbRollback()
commit and rollback the transaction, respectively and turn
auto-commit on.
DBI::dbWithTransaction()
is a convenient wrapper that makes sure that
dbCommit()
or dbRollback()
is called.
1 2 3 4 5 6 7 8 9 |
conn |
a |
.name |
For backward compatibility, do not use. |
... |
Needed for compatibility with generic. Otherwise ignored. |
name |
Supply a name to use a named savepoint. This allows you to nest multiple transaction |
The corresponding generic functions DBI::dbBegin()
, DBI::dbCommit()
,
and DBI::dbRollback()
.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 | library(DBI)
con <- dbConnect(SQLite(), ":memory:")
dbWriteTable(con, "arrests", datasets::USArrests)
dbGetQuery(con, "select count(*) from arrests")
dbBegin(con)
rs <- dbSendStatement(con, "DELETE from arrests WHERE Murder > 1")
dbGetRowsAffected(rs)
dbClearResult(rs)
dbGetQuery(con, "select count(*) from arrests")
dbRollback(con)
dbGetQuery(con, "select count(*) from arrests")[1, ]
dbBegin(con)
rs <- dbSendStatement(con, "DELETE FROM arrests WHERE Murder > 5")
dbClearResult(rs)
dbCommit(con)
dbGetQuery(con, "SELECT count(*) FROM arrests")[1, ]
# Named savepoints can be nested --------------------------------------------
dbBegin(con, name = "a")
dbBegin(con, name = "b")
dbRollback(con, name = "b")
dbCommit(con, name = "a")
dbDisconnect(con)
|
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