Fix for CONPY-116: Wrong type reported for SQL type JSON

Beginning of MariaDB 10.5 metadata for JSON columns is stored in extended field information, and the reported type is MYSQL_TYPE_BLOB. We now check extended field information to return correct type and for fetching values in correct format.
mariadb-corporation · Sep 29, 2020 · 5d4a8d5 · 5d4a8d5
1 parent 6ab09b2
commit 5d4a8d5
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Showing 4 changed files with 32 additions and 5 deletions.
diff --git a/include/mariadb_python.h b/include/mariadb_python.h
@@ -99,6 +99,12 @@ enum enum_dataapi_groups
     DBAPI_ROWID
 };
 
+enum enum_extended_field_type
+{
+  EXT_TYPE_NONE=0,
+  EXT_TYPE_JSON=1
+};
+
 enum enum_result_format
 {
     RESULT_TUPLE= 0,
@@ -322,6 +328,8 @@ mariadb_throw_exception(void *handle,
     const char *message,
     ...);
 
+enum enum_extended_field_type mariadb_extended_field_type(const MYSQL_FIELD *field);
+
 PyObject *
 MrdbIndicator_Object(uint32_t type);
 

diff --git a/mariadb/mariadb_codecs.c b/mariadb/mariadb_codecs.c
@@ -40,6 +40,18 @@ int codecs_datetime_init(void)
     return 0;
 }
 
+
+enum enum_extended_field_type mariadb_extended_field_type(const MYSQL_FIELD *field)
+{
+    MARIADB_CONST_STRING str;
+
+    if (!mariadb_field_attr(&str, field, MARIADB_FIELD_ATTR_FORMAT_NAME))
+    {
+      if (str.length == 4 && !strncmp(str.str, "json", 4))
+          return EXT_TYPE_JSON;
+    }
+    return EXT_TYPE_NONE;
+}
 /*
    converts a Python date/time/datetime object to MYSQL_TIME
  */
@@ -503,8 +515,8 @@ field_fetch_fromtext(MrdbCursor *self, char *data, unsigned int column)
         case MYSQL_TYPE_ENUM:
         {
             unsigned long len;
-
-            if ( self->fields[column].charsetnr == CHARSET_BINARY)
+            enum enum_extended_field_type ext_type= mariadb_extended_field_type(&self->fields[column]);
+            if ( self->fields[column].charsetnr == CHARSET_BINARY && ext_type != EXT_TYPE_JSON)
             {
                 self->values[column]=
                         PyBytes_FromStringAndSize((const char *)data,
@@ -735,9 +747,11 @@ field_fetch_callback(void *data, unsigned int column, unsigned char **row)
             unsigned long length;
             unsigned long utf8len;
             length= mysql_net_field_length(row);
+            enum enum_extended_field_type ext_type= mariadb_extended_field_type(&self->fields[column]);
 
-            if (self->fields[column].flags & BINARY_FLAG ||
-                self->fields[column].charsetnr == CHARSET_BINARY)
+            if ((self->fields[column].flags & BINARY_FLAG ||
+                self->fields[column].charsetnr == CHARSET_BINARY) &&
+                ext_type != EXT_TYPE_JSON)
             {
                 self->values[column]=
                         PyBytes_FromStringAndSize((const char *)*row,

diff --git a/mariadb/mariadb_cursor.c b/mariadb/mariadb_cursor.c
@@ -883,6 +883,7 @@ PyObject *MrdbCursor_description(MrdbCursor *self)
             unsigned long display_length;
             long packed_len= 0;
             PyObject *desc;
+            enum enum_extended_field_type ext_type= mariadb_extended_field_type(&self->fields[i]);
 
             display_length= self->fields[i].max_length > self->fields[i].length ? 
                             self->fields[i].max_length : self->fields[i].length;
@@ -906,6 +907,9 @@ PyObject *MrdbCursor_description(MrdbCursor *self)
                 }
             }
 
+            if (ext_type == EXT_TYPE_JSON)
+                self->fields[i].type= MYSQL_TYPE_JSON;
+
             if (!(desc= Py_BuildValue("(sIIiIIOI)",
                             self->fields[i].name,
                             self->fields[i].type,

diff --git a/testing/test/integration/test_cursor.py b/testing/test/integration/test_cursor.py
@@ -228,7 +228,7 @@ def test_xfield_types(self):
         fieldinfo = mariadb.fieldinfo()
         cursor.execute(
             "CREATE TEMPORARY TABLE test_xfield_types (a tinyint not null auto_increment primary "
-            "key, b smallint, c int, d bigint, e float, f decimal, g double, h char(10), i varchar(255), j blob, index(b))");
+            "key, b smallint, c int, d bigint, e float, f decimal, g double, h char(10), i varchar(255), j blob, k json, index(b))");
         info = cursor.description
         self.assertEqual(info, None)
         cursor.execute("SELECT * FROM test_xfield_types")
@@ -243,6 +243,7 @@ def test_xfield_types(self):
         self.assertEqual(fieldinfo.type(info[7]), "STRING")
         self.assertEqual(fieldinfo.type(info[8]), "VAR_STRING")
         self.assertEqual(fieldinfo.type(info[9]), "BLOB")
+        self.assertEqual(fieldinfo.type(info[10]), "JSON")
         self.assertEqual(fieldinfo.flag(info[0]),
                          "NOT_NULL | PRIMARY_KEY | AUTO_INCREMENT | NUMERIC")
         self.assertEqual(fieldinfo.flag(info[1]), "PART_KEY | NUMERIC")