Merge pull request ps0uth#55 from rraub/54-add-comments

expanded the migration to use the comments from mysql

Author: kworr

mysql2pgsql/lib/mysql_reader.py

@@ -85,6 +85,7 @@ def __init__(self, reader, name):
             self._foreign_keys = []
             self._triggers = []
             self._columns = self._load_columns()
+            self._comment = self._load_table_comment()
             self._load_indexes()
             self._load_triggers()
 
@@ -120,7 +121,7 @@ def _convert_type(self, data_type):
 
         def _load_columns(self):
             fields = []
-            for row in self.reader.db.query('EXPLAIN `%s`' % self.name):
+            for row in self.reader.db.query('SHOW FULL COLUMNS FROM `%s`' % self.name):
                 res = ()
                 for field in row:
                   if type(field) == unicode:
@@ -132,17 +133,19 @@ def _load_columns(self):
                 length = length_match.group(1) if length_match else \
                     precision_match.group(1) if precision_match else None
                 name = res[0]
+                comment = res[8]
                 field_type = self._convert_type(res[1])
                 desc = {
                     'name': name,
                     'table_name': self.name,
                     'type': field_type,
                     'length': int(length) if length else None,
                     'decimals': precision_match.group(2) if precision_match else None,
-                    'null': res[2] == 'YES' or field_type.startswith('enum') or field_type in ('date', 'datetime', 'timestamp'),
-                    'primary_key': res[3] == 'PRI',
-                    'auto_increment': res[5] == 'auto_increment',
-                    'default': res[4] if not res[4] == 'NULL' else None,
+                    'null': res[3] == 'YES' or field_type.startswith('enum') or field_type in ('date', 'datetime', 'timestamp'),
+                    'primary_key': res[4] == 'PRI',
+                    'auto_increment': res[6] == 'auto_increment',
+                    'default': res[5] if not res[5] == 'NULL' else None,
+                    'comment': comment,
                     'select': '`%s`' % name if not field_type.startswith('enum') else
                         'CASE `%(name)s` WHEN "" THEN NULL ELSE `%(name)s` END' % {'name': name},
                     }
@@ -154,6 +157,12 @@ def _load_columns(self):
 
             return fields
 
+        def _load_table_comment(self):
+            table_status = self.reader.db.query('SHOW TABLE STATUS WHERE Name="%s"' % self.name, one=True)
+            comment = table_status[17]
+            return comment
+
+          
         def _load_indexes(self):
             explain = self.reader.db.query('SHOW CREATE TABLE `%s`' % self.name, one=True)
             explain = explain[1]
@@ -207,6 +216,10 @@ def name(self):
         def columns(self):
             return self._columns
 
+        @property
+        def comment(self):
+            return self._comment
+
         @property
         def indexes(self):
             return self._indexes

mysql2pgsql/lib/postgres_writer.py

@@ -131,6 +131,23 @@ def get_type(column):
 
         return '%s%s%s' % (column_type, (default if not default == None else ''), null)
 
+    def table_comments(self, table):
+        comments = StringIO()
+        if table.comment: 
+          comments.write(self.table_comment(table.name, table.comment))
+        for column in table.columns:
+          comments.write(self.column_comment(table.name, column))
+        return comments.getvalue() 
+
+    def column_comment(self, tablename, column):
+      if not column['comment']: 
+        return (' COMMENT ON COLUMN %s.%s is %s;' % ( tablename, column['name'], QuotedString(column['comment']).getquoted()))
+      else: 
+        return ''
+
+    def table_comment(self, tablename, comment):
+        return (' COMMENT ON TABLE %s is %s;' % ( tablename, QuotedString(comment).getquoted()))
+
     def process_row(self, table, row):
         """Examines row data from MySQL and alters
         the values when necessary to be compatible with
@@ -222,6 +239,7 @@ def write_table(self, table):
 
         table_sql.append('DROP TABLE IF EXISTS "%s" CASCADE;' % table.name)
         table_sql.append('CREATE TABLE "%s" (\n%s\n)\nWITHOUT OIDS;' % (table.name.encode('utf8'), columns))
+        table_sql.append( self.table_comments(table))
         return (table_sql, serial_key_sql)
 
     def write_indexes(self, table):