ksql_trans_exclopen,
ksql_trans_open,
ksql_trans_singleopen —
open a database transaction
library “ksql”
#include
<sys/types.h>
#include
<stdint.h>
#include
<ksql.h>
enum ksqlc
ksql_trans_exclopen(
struct
ksql *sql,
size_t id);
enum ksqlc
ksql_trans_open(
struct
ksql *sql,
size_t id);
enum ksqlc
ksql_trans_singleopen(
struct
ksql *sql,
size_t id);
The
ksql_trans_exclopen(),
ksql_trans_open(), and
ksql_trans_singleopen() functions open
transactions with different lock states. All functions accept
sql, the database connection; and
id, an identifier used in error reporting and
in making sure that transaction calls are symmetric. Each of these functions
must be followed by
ksql_trans_commit(3) or
ksql_trans_rollback(3).
If
ksql_trans_open() is used (a
“DEFERRED” transaction, in SQLite terms), the database is locked
only when the first database operation is invoked. The lock is read-shared
(multiple readers, no writers) for a read operation and is upgraded to
write-single (multiple readers, single writer) on a write.
If
ksql_trans_singleopen() is used
(“IMMEDIATE”), the database is immediately locked in
write-single mode.
If
ksql_trans_exclopen()
(“EXCLUSIVE”), the database is opened in a write-exclusive lock,
where only the calling process may write or read from the database.
Recursive transactions are disallowed.
This returns
KSQL_NOTOPEN if the database
connection is not open,
KSQL_TRANS if a
transaction is already open,
KSQL_DB if
errors occurred on the database, or
KSQL_OK
on success.
sqlite3_exec(3)