migrations/versions/201506051421_4074211727ba_add_indico_unaccent_function.py

   1 """Add indico_unaccent function
   2
   3 Revision ID: 4074211727ba
   4 Revises: 3f3a9554a6da
   5 Create Date: 2015-06-05 14:21:52.752777
   6 """
   7
   8 from alembic import op
   9
  10 # revision identifiers, used by Alembic.
  11 revision = '4074211727ba'
  12 down_revision = '3f3a9554a6da'
  13
  14 SQL_FUNCTION_TEMPLATE = '''
  15     CREATE FUNCTION indico_unaccent(value TEXT)
  16         RETURNS TEXT
  17     AS $$
  18     BEGIN
  19         RETURN {return_value};
  20     END;
  21     $$
  22     LANGUAGE plpgsql;
  23 '''
  24
  25
  26 def upgrade():
  27     conn = op.get_bind()
  28     unaccent_extension_installed = conn.execute("""
  29         SELECT EXISTS(SELECT TRUE FROM pg_extension WHERE extname = 'unaccent')
  30     """).scalar()
  31
  32     if unaccent_extension_installed:
  33         conn.execute(SQL_FUNCTION_TEMPLATE.format(return_value='unaccent(value)'))
  34     else:
  35         conn.execute(SQL_FUNCTION_TEMPLATE.format(return_value='value'))
  36
  37
  38 def downgrade():
  39     conn = op.get_bind()
  40     conn.execute("DROP FUNCTION indico_unaccent(TEXT)")