Add connection.quote_ident(str)

Also use PQescapeIdentifier to quote cursor name.

doc/src/connection.rst

@@ -582,6 +582,16 @@ The ``connection`` class
 
             .. __: http://www.postgresql.org/docs/current/static/libpq-status.html#LIBPQ-PQTRANSACTIONSTATUS
 
+    .. method:: quote_ident(str)
+    
+        Return quoted identifier according to PostgreSQL quoting rules.
+
+        Requires libpq >= 9.0.
+
+        .. seealso:: libpq docs for `PQescapeIdentifier()`__.
+
+            .. __: http://www.postgresql.org/docs/current/static/libpq-exec.html#LIBPQ-PQESCAPEIDENTIFIER
+
 
     .. index::
         pair: Protocol; Version

psycopg/connection_type.c

@@ -733,6 +733,38 @@ psyco_conn_get_parameter_status(connectionObject *self, PyObject *args)
     return conn_text_from_chars(self, val);
 }
 
+/* quote_ident - Quote identifier */
+
+#define psyco_conn_quote_ident_doc \
+"quote_ident(str) -- Quote identifier according to PostgreSQL quoting rules.\n\n" \
+"Requires libpq >= 9.0, which provides PQescapeIdentifier()."
+
+static PyObject *
+psyco_conn_quote_ident(connectionObject *self, PyObject *args)
+{
+#if PG_VERSION_NUM >= 90000
+    const char *str = NULL;
+    char *quoted;
+    PyObject *result;
+
+    EXC_IF_CONN_CLOSED(self);
+
+    if (!PyArg_ParseTuple(args, "s", &str)) return NULL;
+
+    quoted = PQescapeIdentifier(self->pgconn, str, strlen(str));
+    if (!quoted) {
+        PyErr_NoMemory();
+        return NULL;
+    }
+    result = conn_text_from_chars(self, quoted);
+    PQfreemem(quoted);
+
+    return result;
+#else
+    PyErr_SetString(NotSupportedError, "PQescapeIdentifier not supported by libpq < 9.0");
+#endif
+}
+
 
 /* lobject method - allocate a new lobject */
 
@@ -991,6 +1023,8 @@ static struct PyMethodDef connectionObject_methods[] = {
      METH_NOARGS, psyco_conn_isexecuting_doc},
     {"cancel", (PyCFunction)psyco_conn_cancel,
      METH_NOARGS, psyco_conn_cancel_doc},
+    {"quote_ident", (PyCFunction)psyco_conn_quote_ident,
+     METH_VARARGS, psyco_conn_quote_ident_doc},
     {NULL}
 };
 

psycopg/cursor_type.c

@@ -1815,7 +1815,7 @@ cursor_setup(cursorObject *self, connectionObject *conn, const char *name)
     Dprintf("cursor_setup: parameters: name = %s, conn = %p", name, conn);
 
     if (name) {
-        if (!(self->name = psycopg_escape_identifier_easy(name, 0))) {
+        if (!(self->name = psycopg_escape_identifier(conn, name, 0))) {
             return -1;
         }
     }

psycopg/psycopg.h

@@ -124,6 +124,7 @@ RAISES HIDDEN PyObject *psyco_set_error(PyObject *exc, cursorObject *curs, const
 HIDDEN char *psycopg_escape_string(connectionObject *conn,
               const char *from, Py_ssize_t len, char *to, Py_ssize_t *tolen);
 HIDDEN char *psycopg_escape_identifier_easy(const char *from, Py_ssize_t len);
+HIDDEN char *psycopg_escape_identifier(connectionObject *conn, const char *from, Py_ssize_t len);
 HIDDEN int psycopg_strdup(char **to, const char *from, Py_ssize_t len);
 HIDDEN int psycopg_is_text_file(PyObject *f);
 

psycopg/utils.c

@@ -87,7 +87,7 @@ psycopg_escape_string(connectionObject *conn, const char *from, Py_ssize_t len,
     return to;
 }
 
-/* Escape a string to build a valid PostgreSQL identifier
+/* Escape a string to build a valid PostgreSQL identifier.
  *
  * Allocate a new buffer on the Python heap containing the new string.
  * 'len' is optional: if 0 the length is calculated.
@@ -96,7 +96,10 @@ psycopg_escape_string(connectionObject *conn, const char *from, Py_ssize_t len,
  *
  * WARNING: this function is not so safe to allow untrusted input: it does no
  * check for multibyte chars. Such a function should be built on
- * PQescapeIndentifier, which is only available from PostgreSQL 9.0.
+ * PQescapeIdentifier, which is only available from PostgreSQL 9.0.
+ *
+ * See below for psycopg_escape_identifier (which requires a connection
+ * object).
  */
 char *
 psycopg_escape_identifier_easy(const char *from, Py_ssize_t len)
@@ -124,6 +127,54 @@ psycopg_escape_identifier_easy(const char *from, Py_ssize_t len)
     return rv;
 }
 
+/* Escape a string to build a valid PostgreSQL identifier.
+ *
+ * Allocate a new buffer on the Python heap containing the new string.
+ * 'len' is optional: if 0 the length is calculated.
+ *
+ * The returned string doesn't include quotes.
+ *
+ * Uses PQescapeIdentifier internally, if available.
+ */
+#if PG_VERSION_NUM >= 90000
+char *
+psycopg_escape_identifier(connectionObject *conn, const char *from, Py_ssize_t len)
+{
+    char *rv;
+    char *str;
+    Py_ssize_t res_len;
+
+    if (!len) { len = strlen(from); }
+    str = PQescapeIdentifier(conn->pgconn, from, len);
+    if (!str) {
+        PyErr_NoMemory();
+        return NULL;
+    }
+
+    res_len = strlen(str);
+    /* allocate enough mem, sans the quotes */
+    if (!(rv = PyMem_New(char, 1 + res_len - 2))) {
+        free(str);
+        PyErr_NoMemory();
+        return NULL;
+    }
+    /* de-quote */
+    strncpy(rv, str + 1, res_len - 2);
+    rv[res_len - 2] = 0;
+
+    PQfreemem(str);
+
+    return rv;
+}
+#else
+char *
+psycopg_escape_identifier(connectionObject *conn, const char *from, Py_ssize_t len)
+{
+    (void) conn;
+    return psycopg_escape_identifier_easy(from, len);
+}
+#endif
+
 /* Duplicate a string.
  *
  * Allocate a new buffer on the Python heap containing the new string.

tests/test_quote.py

@@ -23,7 +23,7 @@
 # License for more details.
 
 import sys
-from testutils import unittest, ConnectingTestCase
+from testutils import unittest, ConnectingTestCase, skip_before_libpq
 
 import psycopg2
 import psycopg2.extensions
@@ -165,6 +165,13 @@ class TestQuotedString(ConnectingTestCase):
         self.assertEqual(q.encoding, 'utf_8')
 
 
+class TestQuotedIdentifier(ConnectingTestCase):
+    @skip_before_libpq(9, 0)
+    def test_identifier(self):
+        self.assertEqual(self.conn.quote_ident('blah-blah'), '"blah-blah"')
+        self.assertEqual(self.conn.quote_ident('quote"inside'), '"quote""inside"')
+
+
 def test_suite():
     return unittest.TestLoader().loadTestsFromName(__name__)