Merge pull request #46 from gms8994/master

Copy triggers existing on MySQL tables to Postgres

mysql2pgsql/lib/__init__.py

@@ -51,6 +51,7 @@ def status_logger(f):
     constraints_template = 'ADDING CONSTRAINTS ON %s'
     write_contents_template = 'WRITING DATA TO %s'
     index_template = 'ADDING INDEXES TO %s'
+    trigger_template = 'ADDING TRIGGERS TO %s'
     statuses = {
         'truncate': {
             'start': start_template % truncate_template,
@@ -72,6 +73,10 @@ def status_logger(f):
             'start': start_template % index_template,
             'finish': finish_template % index_template,
             },
+        'write_triggers': {
+            'start': start_template % trigger_template,
+            'finish': finish_template % trigger_template,
+            },
     }
 
     @wraps(f)

mysql2pgsql/lib/converter.py

@@ -55,16 +55,19 @@ def convert(self):
 
         if not self.supress_ddl:
             if self.verbose:
-                print_start_table('START CREATING INDEXES AND CONSTRAINTS')
+                print_start_table('START CREATING INDEXES, CONSTRAINTS, AND TRIGGERS')
 
             for table in tables:
                 self.writer.write_indexes(table)
 
             for table in tables:
                 self.writer.write_constraints(table)
 
+            for table in tables:
+                self.writer.write_triggers(table)
+
             if self.verbose:
-                print_start_table('DONE CREATING INDEXES AND CONSTRAINTS')
+                print_start_table('DONE CREATING INDEXES, CONSTRAINTS, AND TRIGGERS')
 
         if self.verbose:
             print_start_table('\n\n>>>>>>>>>> FINISHED <<<<<<<<<<')

mysql2pgsql/lib/mysql_reader.py

@@ -83,8 +83,10 @@ def __init__(self, reader, name):
             self._name = name
             self._indexes = []
             self._foreign_keys = []
+            self._triggers = []
             self._columns = self._load_columns()
             self._load_indexes()
+            self._load_triggers()
 
         def _convert_type(self, data_type):
             """Normalize MySQL `data_type`"""
@@ -181,6 +183,22 @@ def _load_indexes(self):
                     self._indexes.append(index)
                     continue
 
+        def _load_triggers(self):
+            explain = self.reader.db.query('SHOW TRIGGERS WHERE `table` = \'%s\'' % self.name)
+            for row in explain:
+                if type(row) is tuple:
+                    trigger = {}
+                    trigger['name'] = row[0]
+                    trigger['event'] = row[1]
+                    trigger['statement'] = row[3]
+                    trigger['timing'] = row[4]
+
+                    trigger['statement'] = re.sub('^BEGIN', '', trigger['statement'])
+                    trigger['statement'] = re.sub('^END', '', trigger['statement'], flags=re.MULTILINE)
+                    trigger['statement'] = re.sub('`', '', trigger['statement'])
+
+                    self._triggers.append(trigger)
+
         @property
         def name(self):
             return self._name
@@ -197,6 +215,10 @@ def indexes(self):
         def foreign_keys(self):
             return self._foreign_keys
 
+        @property
+        def triggers(self):
+            return self._triggers
+
         @property
         def query_for(self):
             return 'SELECT %(column_names)s FROM `%(table_name)s`' % {

mysql2pgsql/lib/postgres_db_writer.py

@@ -166,6 +166,19 @@ def write_indexes(self, table):
         for sql in index_sql:
             self.execute(sql)
 
+    @status_logger
+    def write_triggers(self, table):
+        """Send DDL to create the specified `table` triggers
+
+        :Parameters:
+          - `table`: an instance of a :py:class:`mysql2pgsql.lib.mysql_reader.MysqlReader.Table` object that represents the table to read/write.
+
+        Returns None
+        """
+        index_sql = super(PostgresDbWriter, self).write_triggers(table)
+        for sql in index_sql:
+            self.execute(sql)
+
     @status_logger
     def write_constraints(self, table):
         """Send DDL to create the specified `table` constraints

mysql2pgsql/lib/postgres_file_writer.py

@@ -100,6 +100,17 @@ def write_constraints(self, table):
         """
         self.f.write('\n'.join(super(PostgresFileWriter, self).write_constraints(table)))
 
+    @status_logger
+    def write_triggers(self, table):
+        """Write TRIGGERs existing on `table` to the output file
+
+        :Parameters:
+          - `table`: an instance of a :py:class:`mysql2pgsql.lib.mysql_reader.MysqlReader.Table` object that represents the table to read/write.
+
+        Returns None
+        """
+        self.f.write('\n'.join(super(PostgresFileWriter, self).write_triggers(table)))
+
     @status_logger
     def write_contents(self, table, reader):
         """Write the data contents of `table` to the output file.

mysql2pgsql/lib/postgres_writer.py

@@ -259,6 +259,32 @@ def write_constraints(self, table):
                 'ref_column_name': key['ref_column']})
         return constraint_sql
 
+    def write_triggers(self, table):
+        trigger_sql = []
+        for key in table.triggers:
+            trigger_sql.append("""CREATE OR REPLACE FUNCTION %(fn_trigger_name)s RETURNS TRIGGER AS $%(trigger_name)s$
+            BEGIN
+                %(trigger_statement)s
+            RETURN NULL;
+            END;
+            $%(trigger_name)s$ LANGUAGE plpgsql;""" % {
+                'table_name': table.name,
+                'trigger_time': key['timing'],
+                'trigger_event': key['event'],
+                'trigger_name': key['name'],
+                'fn_trigger_name': 'fn_' + key['name'] + '()',
+                'trigger_statement': key['statement']})
+
+            trigger_sql.append("""CREATE TRIGGER %(trigger_name)s %(trigger_time)s %(trigger_event)s ON %(table_name)s
+            FOR EACH ROW
+            EXECUTE PROCEDURE fn_%(trigger_name)s();""" % {
+                'table_name': table.name,
+                'trigger_time': key['timing'],
+                'trigger_event': key['event'],
+                'trigger_name': key['name']})
+
+        return trigger_sql
+
     def close(self):
         raise NotImplementedError