dbBegin_SQLiteConnection | R Documentation |
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.
A helper function sqliteIsTransacting()
is available to check the current
transaction status of the connection.
## S4 method for signature 'SQLiteConnection'
dbBegin(conn, .name = NULL, ..., name = NULL)
## S4 method for signature 'SQLiteConnection'
dbCommit(conn, .name = NULL, ..., name = NULL)
## S4 method for signature 'SQLiteConnection'
dbRollback(conn, .name = NULL, ..., name = NULL)
sqliteIsTransacting(conn)
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()
.
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")
sqliteIsTransacting(con)
dbRollback(con, name = "b")
dbCommit(con, name = "a")
dbDisconnect(con)
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