diff --git a/Lib/sqlite3/test/transactions.py b/Lib/sqlite3/test/transactions.py index 45f1b04c696..b8a13de55bc 100644 --- a/Lib/sqlite3/test/transactions.py +++ b/Lib/sqlite3/test/transactions.py @@ -179,6 +179,15 @@ class TransactionalDDL(unittest.TestCase): result = self.con.execute("select * from test").fetchall() self.assertEqual(result, []) + def CheckImmediateTransactionalDDL(self): + # You can achieve transactional DDL by issuing a BEGIN + # statement manually. + self.con.execute("begin immediate") + self.con.execute("create table test(i)") + self.con.rollback() + with self.assertRaises(sqlite.OperationalError): + self.con.execute("select * from test") + def CheckTransactionalDDL(self): # You can achieve transactional DDL by issuing a BEGIN # statement manually. diff --git a/Misc/NEWS b/Misc/NEWS index 4413c511157..8949ab4c75e 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -249,6 +249,9 @@ Extension Modules Library ------- +- bpo-28518: Start a transaction implicitly before a DML statement. + Patch by Aviv Palivoda. + - Issue #16285: urrlib.parse.quote is now based on RFC 3986 and hence includes '~' in the set of characters that is not quoted by default. Patch by Christian Theune and Ratnadeep Debnath. diff --git a/Modules/_sqlite/cursor.c b/Modules/_sqlite/cursor.c index 39f7a6508c2..8341fb84801 100644 --- a/Modules/_sqlite/cursor.c +++ b/Modules/_sqlite/cursor.c @@ -511,10 +511,9 @@ PyObject* _pysqlite_query_execute(pysqlite_Cursor* self, int multiple, PyObject* pysqlite_statement_reset(self->statement); pysqlite_statement_mark_dirty(self->statement); - /* For backwards compatibility reasons, do not start a transaction if a - DDL statement is encountered. If anybody wants transactional DDL, - they can issue a BEGIN statement manually. */ - if (self->connection->begin_statement && !sqlite3_stmt_readonly(self->statement->st) && !self->statement->is_ddl) { + /* We start a transaction implicitly before a DML statement. + SELECT is the only exception. See #9924. */ + if (self->connection->begin_statement && self->statement->is_dml) { if (sqlite3_get_autocommit(self->connection->db)) { result = _pysqlite_connection_begin(self->connection); if (!result) { @@ -609,7 +608,7 @@ PyObject* _pysqlite_query_execute(pysqlite_Cursor* self, int multiple, PyObject* } } - if (!sqlite3_stmt_readonly(self->statement->st)) { + if (self->statement->is_dml) { self->rowcount += (long)sqlite3_changes(self->connection->db); } else { self->rowcount= -1L; diff --git a/Modules/_sqlite/statement.c b/Modules/_sqlite/statement.c index 8b45a033204..27b2654b103 100644 --- a/Modules/_sqlite/statement.c +++ b/Modules/_sqlite/statement.c @@ -73,8 +73,9 @@ int pysqlite_statement_create(pysqlite_Statement* self, pysqlite_Connection* con Py_INCREF(sql); self->sql = sql; - /* determine if the statement is a DDL statement */ - self->is_ddl = 0; + /* Determine if the statement is a DML statement. + SELECT is the only exception. See #9924. */ + self->is_dml = 0; for (p = sql_cstr; *p != 0; p++) { switch (*p) { case ' ': @@ -84,9 +85,10 @@ int pysqlite_statement_create(pysqlite_Statement* self, pysqlite_Connection* con continue; } - self->is_ddl = (PyOS_strnicmp(p, "create ", 7) == 0) - || (PyOS_strnicmp(p, "drop ", 5) == 0) - || (PyOS_strnicmp(p, "reindex ", 8) == 0); + self->is_dml = (PyOS_strnicmp(p, "insert ", 7) == 0) + || (PyOS_strnicmp(p, "update ", 7) == 0) + || (PyOS_strnicmp(p, "delete ", 7) == 0) + || (PyOS_strnicmp(p, "replace ", 8) == 0); break; } diff --git a/Modules/_sqlite/statement.h b/Modules/_sqlite/statement.h index 6eef16857f7..8db10f6649c 100644 --- a/Modules/_sqlite/statement.h +++ b/Modules/_sqlite/statement.h @@ -38,7 +38,7 @@ typedef struct sqlite3_stmt* st; PyObject* sql; int in_use; - int is_ddl; + int is_dml; PyObject* in_weakreflist; /* List of weak references */ } pysqlite_Statement;