You shouldn't need to build your code as strings. To access tables whose
names are stored in variables, you can do db[tablename] instead of 'db.' +
tablename. And to build queries one condition at a time, you can use
in-place operators -- from the book:
It is also possible to build queries using in-place logical operators:
>>> query = db.person.name!='Alex'
>>> query &= db.person.id>3
>>> query |= db.person.name=='John'
Anthony
On Sunday, September 30, 2012 1:37:47 PM UTC-4, JaapP wrote:
>
> Hi All,
>
> In the past few days i have been struggling with the problem of generating
> a dynamic query.
>
> My goal is to create a reusable model, which gives the possibility to
> search all fields in a given table for the presence of a string. The result
> will be a list of id's with the records in which the searched string is
> present in any field.
>
> My problem always comes down to the simple point that, although i am able
> to build a query by examining the table, in the end my constructed query is
> a string.
> Whenever i try to execute i get an error, as far as i understand caused by
> the feeding of a string to the db().
>
> Can anybody give me a hint in the right direction?
>
> Thanks in advance,
>
> Jaap
>
>
> My sample (*not working*) code:
>
> class SmartSearch(object):
>
> def __init__(self,table):
> _start_query = ''
> _fields = []
> _select = ''
> _start_query += '(db.' + str(table) + '.id>0)&'
> _select += 'db.' + str(table) + '.id,'
> for item in table:
> _fields.append(str(item))
> if type(item.requires).__name__ == 'IS_IN_DB':
> _start_query += '(' + 'db.' + str(item) + '==db.' + str(
> item.requires.ktable) + '.id' + ')&'
> self._start_query = _start_query[:-1]
> self._select = _select
> self._fields = _fields
> return
>
> def search(self, search_string, search_mode='AND'):
> items = search_string.split()
> _query = ''
> for item in items:
> _sub_query = ''
> for field in self._fields:
> _sub_query += '(db.' + field + '.like("%' + item + '%"))|'
> _sub_query = _sub_query[:-1]
> _sub_query = '(' + _sub_query + ')'
> if search_mode == 'AND':
> _query += _sub_query + '&'
> else:
> _query += _sub_query + '|'
> _query = _query[:-1]
> totaal_query = self._start_query + '(' + _query + ')'
> result = db(totaal_query).select(self._select)
> return
>
>
>
>
>
--
