我们从Python开源项目中，提取了以下50个代码示例，用于说明如何使用psycopg2.extensions.ISOLATION_LEVEL_READ_COMMITTED。
def test_isolation_level_read_committed(self): cnn1 = self.connect() cnn2 = self.connect() cnn2.set_isolation_level(ext.ISOLATION_LEVEL_READ_COMMITTED) cur1 = cnn1.cursor() cur1.execute("select count(*) from isolevel;") self.assertEqual(0, cur1.fetchone()[0]) cnn1.commit() cur2 = cnn2.cursor() cur2.execute("insert into isolevel values (10);") cur1.execute("insert into isolevel values (20);") cur2.execute("select count(*) from isolevel;") self.assertEqual(1, cur2.fetchone()[0]) cnn1.commit() cur2.execute("select count(*) from isolevel;") self.assertEqual(2, cur2.fetchone()[0]) cur1.execute("select count(*) from isolevel;") self.assertEqual(1, cur1.fetchone()[0]) cnn2.commit() cur1.execute("select count(*) from isolevel;") self.assertEqual(2, cur1.fetchone()[0])
def _isolation_lookup(self): extensions = self._psycopg2_extensions() return { 'AUTOCOMMIT': extensions.ISOLATION_LEVEL_AUTOCOMMIT, 'READ COMMITTED': extensions.ISOLATION_LEVEL_READ_COMMITTED, 'READ UNCOMMITTED': extensions.ISOLATION_LEVEL_READ_UNCOMMITTED, 'REPEATABLE READ': extensions.ISOLATION_LEVEL_REPEATABLE_READ, 'SERIALIZABLE': extensions.ISOLATION_LEVEL_SERIALIZABLE }
def connect(*args, **kwargs): """connect(dsn, ...) -> new psycopg 1.1.x compatible connection object""" kwargs['connection_factory'] = connection conn = _2connect(*args, **kwargs) conn.set_isolation_level(_ext.ISOLATION_LEVEL_READ_COMMITTED) return conn
def autocommit(self, on_off=1): """autocommit(on_off=1) -> switch autocommit on (1) or off (0)""" if on_off > 0: self.set_isolation_level(_ext.ISOLATION_LEVEL_AUTOCOMMIT) else: self.set_isolation_level(_ext.ISOLATION_LEVEL_READ_COMMITTED)
def test_set_isolation_level(self): conn = self.connect() curs = conn.cursor() levels = [ ('read uncommitted', ext.ISOLATION_LEVEL_READ_UNCOMMITTED), ('read committed', ext.ISOLATION_LEVEL_READ_COMMITTED), ('repeatable read', ext.ISOLATION_LEVEL_REPEATABLE_READ), ('serializable', ext.ISOLATION_LEVEL_SERIALIZABLE), ] for name, level in levels: conn.set_isolation_level(level) # the only values available on prehistoric PG versions if conn.server_version < 80000: if level in ( ext.ISOLATION_LEVEL_READ_UNCOMMITTED, ext.ISOLATION_LEVEL_REPEATABLE_READ): name, level = levels[levels.index((name, level)) + 1] self.assertEqual(conn.isolation_level, level) curs.execute('show transaction_isolation;') got_name = curs.fetchone()[0] self.assertEqual(name, got_name) conn.commit() self.assertRaises(ValueError, conn.set_isolation_level, -1) self.assertRaises(ValueError, conn.set_isolation_level, 5)
def test_set_isolation_level_abort(self): conn = self.connect() cur = conn.cursor() self.assertEqual(ext.TRANSACTION_STATUS_IDLE, conn.get_transaction_status()) cur.execute("insert into isolevel values (10);") self.assertEqual(ext.TRANSACTION_STATUS_INTRANS, conn.get_transaction_status()) conn.set_isolation_level( psycopg2.extensions.ISOLATION_LEVEL_SERIALIZABLE) self.assertEqual(psycopg2.extensions.TRANSACTION_STATUS_IDLE, conn.get_transaction_status()) cur.execute("select count(*) from isolevel;") self.assertEqual(0, cur.fetchone()[0]) cur.execute("insert into isolevel values (10);") self.assertEqual(psycopg2.extensions.TRANSACTION_STATUS_INTRANS, conn.get_transaction_status()) conn.set_isolation_level( psycopg2.extensions.ISOLATION_LEVEL_AUTOCOMMIT) self.assertEqual(psycopg2.extensions.TRANSACTION_STATUS_IDLE, conn.get_transaction_status()) cur.execute("select count(*) from isolevel;") self.assertEqual(0, cur.fetchone()[0]) cur.execute("insert into isolevel values (10);") self.assertEqual(psycopg2.extensions.TRANSACTION_STATUS_IDLE, conn.get_transaction_status()) conn.set_isolation_level( psycopg2.extensions.ISOLATION_LEVEL_READ_COMMITTED) self.assertEqual(psycopg2.extensions.TRANSACTION_STATUS_IDLE, conn.get_transaction_status()) cur.execute("select count(*) from isolevel;") self.assertEqual(1, cur.fetchone()[0]) self.assertEqual(conn.isolation_level, psycopg2.extensions.ISOLATION_LEVEL_READ_COMMITTED)
def test_set_isolation_level(self): cur = self.conn.cursor() self.conn.set_session( ext.ISOLATION_LEVEL_SERIALIZABLE) cur.execute("SHOW transaction_isolation;") self.assertEqual(cur.fetchone()[0], 'serializable') self.conn.rollback() self.conn.set_session( ext.ISOLATION_LEVEL_REPEATABLE_READ) cur.execute("SHOW transaction_isolation;") if self.conn.server_version > 80000: self.assertEqual(cur.fetchone()[0], 'repeatable read') else: self.assertEqual(cur.fetchone()[0], 'serializable') self.conn.rollback() self.conn.set_session( isolation_level=ext.ISOLATION_LEVEL_READ_COMMITTED) cur.execute("SHOW transaction_isolation;") self.assertEqual(cur.fetchone()[0], 'read committed') self.conn.rollback() self.conn.set_session( isolation_level=ext.ISOLATION_LEVEL_READ_UNCOMMITTED) cur.execute("SHOW transaction_isolation;") if self.conn.server_version > 80000: self.assertEqual(cur.fetchone()[0], 'read uncommitted') else: self.assertEqual(cur.fetchone()[0], 'read committed') self.conn.rollback()
def _isolation_lookup(self): from psycopg2 import extensions return { 'AUTOCOMMIT': extensions.ISOLATION_LEVEL_AUTOCOMMIT, 'READ COMMITTED': extensions.ISOLATION_LEVEL_READ_COMMITTED, 'READ UNCOMMITTED': extensions.ISOLATION_LEVEL_READ_UNCOMMITTED, 'REPEATABLE READ': extensions.ISOLATION_LEVEL_REPEATABLE_READ, 'SERIALIZABLE': extensions.ISOLATION_LEVEL_SERIALIZABLE }
def _isolation_lookup(self): extensions = __import__('psycopg2.extensions').extensions return { 'AUTOCOMMIT': extensions.ISOLATION_LEVEL_AUTOCOMMIT, 'READ COMMITTED': extensions.ISOLATION_LEVEL_READ_COMMITTED, 'READ UNCOMMITTED': extensions.ISOLATION_LEVEL_READ_UNCOMMITTED, 'REPEATABLE READ': extensions.ISOLATION_LEVEL_REPEATABLE_READ, 'SERIALIZABLE': extensions.ISOLATION_LEVEL_SERIALIZABLE }
