Discard any result produced by cursor.executemany()

NEWS

@@ -23,6 +23,7 @@ What's new in psycopg 2.4.6
     RealDictConnection and Cursor (ticket #114).
   - connect() raises an exception instead of swallowing keyword arguments
     when a connection string is specified as well (ticket #131).
+  - Discard any result produced by 'executemany()' (ticket #133).
   - 'errorcodes' map updated to PostgreSQL 9.2.
 
 

psycopg/connection_int.c

@@ -896,7 +896,7 @@ conn_poll(connectionObject *self)
             /* fetch the tuples (if there are any) and build the result. We
              * don't care if pq_fetch return 0 or 1, but if there was an error,
              * we want to signal it to the caller. */
-            if (pq_fetch(curs) == -1) {
+            if (pq_fetch(curs, 0) == -1) {
                res = PSYCO_POLL_ERROR;
             }
 

psycopg/cursor_type.c

@@ -63,7 +63,7 @@ psyco_curs_close(cursorObject *self, PyObject *args)
 
         EXC_IF_NO_MARK(self);
         PyOS_snprintf(buffer, 127, "CLOSE \"%s\"", self->name);
-        if (pq_execute(self, buffer, 0) == -1) return NULL;
+        if (pq_execute(self, buffer, 0, 0) == -1) return NULL;
     }
 
     self->closed = 1;
@@ -365,7 +365,8 @@ _psyco_curs_merge_query_args(cursorObject *self,
 
 RAISES_NEG static int
 _psyco_curs_execute(cursorObject *self,
-                    PyObject *operation, PyObject *vars, long int async)
+                    PyObject *operation, PyObject *vars,
+                    long int async, int no_result)
 {
     int res = -1;
     int tmp;
@@ -450,7 +451,7 @@ _psyco_curs_execute(cursorObject *self,
 
     /* At this point, the SQL statement must be str, not unicode */
 
-    tmp = pq_execute(self, Bytes_AS_STRING(self->query), async);
+    tmp = pq_execute(self, Bytes_AS_STRING(self->query), async, no_result);
     Dprintf("psyco_curs_execute: res = %d, pgres = %p", tmp, self->pgres);
     if (tmp < 0) { goto exit; }
 
@@ -497,7 +498,7 @@ psyco_curs_execute(cursorObject *self, PyObject *args, PyObject *kwargs)
     EXC_IF_ASYNC_IN_PROGRESS(self, execute);
     EXC_IF_TPC_PREPARED(self->conn, execute);
 
-    if (0 > _psyco_curs_execute(self, operation, vars, self->conn->async)) {
+    if (0 > _psyco_curs_execute(self, operation, vars, self->conn->async, 0)) {
         return NULL;
     }
 
@@ -542,7 +543,7 @@ psyco_curs_executemany(cursorObject *self, PyObject *args, PyObject *kwargs)
     }
 
     while ((v = PyIter_Next(vars)) != NULL) {
-        if (0 > _psyco_curs_execute(self, operation, v, 0)) {
+        if (0 > _psyco_curs_execute(self, operation, v, 0, 1)) {
             Py_DECREF(v);
             Py_XDECREF(iter);
             return NULL;
@@ -673,7 +674,7 @@ _psyco_curs_prefetch(cursorObject *self)
     if (self->pgres == NULL) {
         Dprintf("_psyco_curs_prefetch: trying to fetch data");
         do {
-            i = pq_fetch(self);
+            i = pq_fetch(self, 0);
             Dprintf("_psycopg_curs_prefetch: result = %d", i);
         } while(i == 1);
     }
@@ -775,7 +776,7 @@ psyco_curs_fetchone(cursorObject *self, PyObject *args)
         EXC_IF_ASYNC_IN_PROGRESS(self, fetchone);
         EXC_IF_TPC_PREPARED(self->conn, fetchone);
         PyOS_snprintf(buffer, 127, "FETCH FORWARD 1 FROM \"%s\"", self->name);
-        if (pq_execute(self, buffer, 0) == -1) return NULL;
+        if (pq_execute(self, buffer, 0, 0) == -1) return NULL;
         if (_psyco_curs_prefetch(self) < 0) return NULL;
     }
 
@@ -826,7 +827,7 @@ psyco_curs_next_named(cursorObject *self)
 
         PyOS_snprintf(buffer, 127, "FETCH FORWARD %ld FROM \"%s\"",
             self->itersize, self->name);
-        if (pq_execute(self, buffer, 0) == -1) return NULL;
+        if (pq_execute(self, buffer, 0, 0) == -1) return NULL;
         if (_psyco_curs_prefetch(self) < 0) return NULL;
     }
 
@@ -895,7 +896,7 @@ psyco_curs_fetchmany(cursorObject *self, PyObject *args, PyObject *kwords)
         EXC_IF_TPC_PREPARED(self->conn, fetchone);
         PyOS_snprintf(buffer, 127, "FETCH FORWARD %d FROM \"%s\"",
             (int)size, self->name);
-        if (pq_execute(self, buffer, 0) == -1) { goto exit; }
+        if (pq_execute(self, buffer, 0, 0) == -1) { goto exit; }
         if (_psyco_curs_prefetch(self) < 0) { goto exit; }
     }
 
@@ -970,7 +971,7 @@ psyco_curs_fetchall(cursorObject *self, PyObject *args)
         EXC_IF_ASYNC_IN_PROGRESS(self, fetchall);
         EXC_IF_TPC_PREPARED(self->conn, fetchall);
         PyOS_snprintf(buffer, 127, "FETCH FORWARD ALL FROM \"%s\"", self->name);
-        if (pq_execute(self, buffer, 0) == -1) { goto exit; }
+        if (pq_execute(self, buffer, 0, 0) == -1) { goto exit; }
         if (_psyco_curs_prefetch(self) < 0) { goto exit; }
     }
 
@@ -1063,7 +1064,8 @@ psyco_curs_callproc(cursorObject *self, PyObject *args)
 
     if (!(operation = Bytes_FromString(sql))) { goto exit; }
 
-    if (0 <= _psyco_curs_execute(self, operation, parameters, self->conn->async)) {
+    if (0 <= _psyco_curs_execute(self, operation, parameters,
+            self->conn->async, 0)) {
         Py_INCREF(parameters);
         res = parameters;
     }
@@ -1190,7 +1192,7 @@ psyco_curs_scroll(cursorObject *self, PyObject *args, PyObject *kwargs)
         else {
             PyOS_snprintf(buffer, 127, "MOVE %d FROM \"%s\"", value, self->name);
         }
-        if (pq_execute(self, buffer, 0) == -1) return NULL;
+        if (pq_execute(self, buffer, 0, 0) == -1) return NULL;
         if (_psyco_curs_prefetch(self) < 0) return NULL;
     }
 
@@ -1370,7 +1372,7 @@ psyco_curs_copy_from(cursorObject *self, PyObject *args, PyObject *kwargs)
     Py_INCREF(file);
     self->copyfile = file;
 
-    if (pq_execute(self, query, 0) >= 0) {
+    if (pq_execute(self, query, 0, 0) >= 0) {
         res = Py_None;
         Py_INCREF(Py_None);
     }
@@ -1466,7 +1468,7 @@ psyco_curs_copy_to(cursorObject *self, PyObject *args, PyObject *kwargs)
     Py_INCREF(file);
     self->copyfile = file;
 
-    if (pq_execute(self, query, 0) >= 0) {
+    if (pq_execute(self, query, 0, 0) >= 0) {
         res = Py_None;
         Py_INCREF(Py_None);
     }
@@ -1540,7 +1542,7 @@ psyco_curs_copy_expert(cursorObject *self, PyObject *args, PyObject *kwargs)
     self->copyfile = file;
 
     /* At this point, the SQL statement must be str, not unicode */
-    if (pq_execute(self, Bytes_AS_STRING(sql), 0) >= 0) {
+    if (pq_execute(self, Bytes_AS_STRING(sql), 0, 0) >= 0) {
         res = Py_None;
         Py_INCREF(res);
     }

psycopg/pqpath.c

@@ -835,12 +835,16 @@ pq_flush(connectionObject *conn)
 }
 
 /* pq_execute - execute a query, possibly asynchronously
-
+ *
-   this fucntion locks the connection object
+ * With no_result an eventual query result is discarded.
-   this function call Py_*_ALLOW_THREADS macros */
+ * Currently only used to implement cursor.executemany().
+ *
+ * This function locks the connection object
+ * This function call Py_*_ALLOW_THREADS macros
+*/
 
 RAISES_NEG int
-pq_execute(cursorObject *curs, const char *query, int async)
+pq_execute(cursorObject *curs, const char *query, int async, int no_result)
 {
     PGresult *pgres = NULL;
     char *error = NULL;
@@ -944,7 +948,7 @@ pq_execute(cursorObject *curs, const char *query, int async)
        to respect the old DBAPI-2.0 compatible behaviour */
     if (async == 0) {
         Dprintf("pq_execute: entering syncronous DBAPI compatibility mode");
-        if (pq_fetch(curs) < 0) return -1;
+        if (pq_fetch(curs, no_result) < 0) return -1;
     }
     else {
         PyObject *tmp;
@@ -1405,7 +1409,7 @@ exit:
 }
 
 int
-pq_fetch(cursorObject *curs)
+pq_fetch(cursorObject *curs, int no_result)
 {
     int pgstatus, ex = -1;
     const char *rowcount;
@@ -1469,10 +1473,18 @@ pq_fetch(cursorObject *curs)
         break;
 
     case PGRES_TUPLES_OK:
-        Dprintf("pq_fetch: data from a SELECT (got tuples)");
+        if (!no_result) {
-        curs->rowcount = PQntuples(curs->pgres);
+            Dprintf("pq_fetch: got tuples");
-        if (0 == _pq_fetch_tuples(curs)) { ex = 0; }
+            curs->rowcount = PQntuples(curs->pgres);
-        /* don't clear curs->pgres, because it contains the results! */
+            if (0 == _pq_fetch_tuples(curs)) { ex = 0; }
+            /* don't clear curs->pgres, because it contains the results! */
+        }
+        else {
+            Dprintf("pq_fetch: got tuples, discarding them");
+            IFCLEARPGRES(curs->pgres);
+            curs->rowcount = -1;
+            ex = 0;
+        }
         break;
 
     case PGRES_EMPTY_QUERY:

psycopg/pqpath.h

@@ -35,8 +35,9 @@
 
 /* exported functions */
 HIDDEN PGresult *pq_get_last_result(connectionObject *conn);
-RAISES_NEG HIDDEN int pq_fetch(cursorObject *curs);
+RAISES_NEG HIDDEN int pq_fetch(cursorObject *curs, int no_result);
-RAISES_NEG HIDDEN int pq_execute(cursorObject *curs, const char *query, int async);
+RAISES_NEG HIDDEN int pq_execute(cursorObject *curs, const char *query,
+                                 int async, int no_result);
 HIDDEN int pq_send_query(connectionObject *conn, const char *query);
 HIDDEN int pq_begin_locked(connectionObject *conn, PGresult **pgres,
                            char **error, PyThreadState **tstate);