1 #!/usr/bin/env python3

     2 

     3 from pgtoolkit import toolbase

     4 from pgtoolkit.pgmanager import IntegrityError

     5 

     6 

     7 class BatchCopyTool(toolbase.SrcDstTablesTool):

     8     def __init__(self):

     9         toolbase.SrcDstTablesTool.__init__(self, name='batchcopy', desc='Copy data from one table to another.')

    10 

    11         self.parser.add_argument('--table-name', type=str, help='Table to be copied.')

    12         self.parser.add_argument('--src-filter', type=str, help='WHERE condition for source query.')

    13         self.parser.add_argument('--file-with-ids', type=str, help='Read source IDs from file (each ID on new line). Use these in --src-filter as {ids}')

    14         self.parser.add_argument('--dst-exists', choices=['rollback', 'ignore', 'update'], default='rollback', help='What to do when destination record already exists.')

    15 

    16         self.init()

    17 

    18     def main(self):

    19         # read list of IDs from file

    20         ids = '<no IDs read>'

    21         if self.args.file_with_ids:

    22             with open(self.args.file_with_ids, 'r') as f:

    23                 ids = ','.join(ln.rstrip() for ln in f.readlines())

    24 

    25         # read source data

    26         with self.pgm.cursor('src') as src_curs:

    27             condition = self.args.src_filter.format(ids=ids) or 'true'

    28             src_curs.execute('SELECT * FROM {} WHERE {}'.format(self.args.table_name, condition))

    29             #TODO:  ORDER BY id OFFSET 0 LIMIT 100

    30             data = src_curs.fetchall_dict()

    31             src_curs.connection.commit()

    32 

    33         with self.pgm.cursor('dst') as dst_curs:

    34             copied = 0

    35             for row in data:

    36                 keys = ', '.join(row.keys())

    37                 values_mask = ', '.join(['%s'] * len(row))

    38                 query = 'INSERT INTO {} ({}) VALUES ({})'.format(self.args.table_name, keys, values_mask)

    39                 try:

    40                     dst_curs.execute('SAVEPOINT the_query;')

    41                     dst_curs.execute(query, list(row.values()))

    42                     dst_curs.execute('RELEASE SAVEPOINT the_query;')

    43                     copied += 1

    44                 except IntegrityError:

    45                     if self.args.dst_exists == 'rollback':

    46                         dst_curs.connection.rollback()

    47                         break

    48                     elif self.args.dst_exists == 'ignore':

    49                         dst_curs.execute('ROLLBACK TO SAVEPOINT the_query;')

    50                     elif self.args.dst_exists == 'update':

    51                         raise NotImplementedError()

    52             dst_curs.connection.commit()

    53 

    54         self.log.info('Copied %s rows.', copied)

    55 

    56 

    57 tool = BatchCopyTool()

    58 tool.main()