def _get_sql_for_pending_references(model, pending_references):
    """
    Get any ALTER TABLE statements to add constraints after the fact.
    """
    from django.db import backend, get_creation_module
    data_types = get_creation_module().DATA_TYPES

    final_output = []
    if backend.supports_constraints:
        opts = model._meta
        if model in pending_references:
            for rel_class, f in pending_references[model]:
                rel_opts = rel_class._meta
                r_table = rel_opts.db_table
                r_col = f.column
                table = opts.db_table
                col = opts.get_field(f.rel.field_name).column
                # For MySQL, r_name must be unique in the first 64 characters.
                # So we are careful with character usage here.
                r_name = '%s_refs_%s_%x' % (r_col, col, abs(hash((r_table, table))))
                final_output.append(style.SQL_KEYWORD('ALTER TABLE') + ' %s ADD CONSTRAINT %s FOREIGN KEY (%s) REFERENCES %s (%s)%s;' % \
                    (backend.quote_name(r_table), r_name,
                    backend.quote_name(r_col), backend.quote_name(table), backend.quote_name(col), 
                    backend.get_deferrable_sql()))
            del pending_references[model]
    return final_output
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-0.96/django/core/management.py/_get_sql_for_pending_references/original