def query_prepare_parameters(tables, grouping, ordering, fields, joins, querymappings, ua, condition, limit, cachingtime):
# fixup sloppy parameter passing
if isinstance(tables, basestring):
tables = [tables]
if isinstance(grouping, basestring):
grouping = [grouping]
if isinstance(ordering, basestring):
ordering = [ordering]
if isinstance(fields, basestring):
fields = [fields]
if not joins:
joins = []
if not grouping:
grouping = []
if not ordering:
ordering = []
if not fields:
fields = []
tablenames = [_get_tablename(x) for x in tables]
if querymappings == {} and not fields:
raise RuntimeError("Please give fieldnames.")
if querymappings is None and len(fields) != 1:
querymappings = {}
jointables = [table for table, foo, bar in joins]
for table in tables + jointables:
# dubletten = set(querymappings.values()) & set(MAPPINGDIR.get(table, {}).values())
# if dubletten:
# logging.warning('field name clash: %s' % list(dubletten))
querymappings.update(MAPPINGDIR.get(table, {}))
if not fields: # decuce fieldnames from querymappings
fields = querymappings.keys()
if not fields: # still nothing found
raise RuntimeError("can't deduce field names, check fields.py")
args = dict(fields=fields, tablenames=tablenames, tag=ua)
if condition:
args['condition'] = condition
if grouping:
args['grouping'] = grouping
if ordering:
args['ordering'] = ordering
if limit:
args['limit'] = limit
if joins:
# ensure a list of 3-tuples
joins = [(_get_tablename(a), b, c) for (a, b, c) in joins]
args['joins'] = joins
bust_cache = True
if cachingtime > 0:
bust_cache = False
return args, bust_cache, querymappings, fields
def query(tables=None, condition=None, fields=None, querymappings=None,
joins=None,
grouping=None, ordering=None, limit=None, ua='', cachingtime=300):
r"""Execute a SELECT on the AS/400 turning the results in a list of dicts.
In fields you can give a list of fields you are interested in. If fields is left empty the engine
generates a list of field on it own by consulting the field mapping database in from
fields.MAPPINGDIR.
>>> query('ALK00', condition="LKLFSN=4034544") #doctest: +ELLIPSIS
[{'lager': 100, ...}]
To suppress mapping provide querymappings={} and fields=[].
>>> query(tables=['XPN00'], condition="PNSANR=2255")
[{'satznummer': 2255, 'preis': Decimal('16.10')}]
>>> query(tables=['XPN00'], condition="PNSANR=2255",
... fields=['PNSANR', 'PNPRB'], querymappings={})
[(2255, Decimal('16.10'))]
To get only certain fields give a list of fieldnames in fields=[...].
>>> query(tables=['XPN00'], condition="PNSANR=2255", fields=['PNPRB'])
[(Decimal('16.10'),)]
Joins are straightforward if used with condition="<expression>":
>>> query(['XPN00', 'XPR00'], condition="PNSANR=PRSANR and PNSANR=2255",
... fields=['PRDTVO', 'PNPRB'])
[{'preis': Decimal('16.10'), 'gueltig_ab_date': datetime.date(2004, 12, 16)}]
Aggregate functions can be created by using the "grouping" keyword:
>>> sorted(query('XLF00', fields=['LFARTN', 'SUM(LFMGLP)'], grouping=['LFARTN'],
... condition="LFLGNR=3"))
[(u'65166/01', u'0'), (u'65198', u'0'), (u'76095', u'0'), (u'76102', u'0'), (u'ED76095', u'0')]
If desired "querymappings" can be used to return a list of dicts:
>>> sorted(query('XLF00', fields=['LFARTN', 'SUM(LFMGLP)'], grouping=['LFARTN'],
... condition="LFLGNR=3", querymappings={'LFARTN': 'artnr',
... 'SUM(LFMGLP)': 'menge'})) #doctest: +ELLIPSIS
[{'menge': u'0', 'artnr': u'65166/01'}, {'menge': u'0', 'artnr': u'65198'}, ...]
You can use 'joins' to define LEFT OUTER JOINs. E.g.:
>>> rows = query(['XKD00'],
... condition="KDKDNR='%8d'" % int(66669),
... joins=[('XXC00', 'KDKDNR', 'XCADNR'),
... ('XKS00', 'KDKDNR', 'KSKDNR'),
... ('AKZ00', 'KDKDNR', 'KZKDNR')])
Will result in "SELECT * FROM XKD00 LEFT OUTER JOIN XXC00 ON KDKDNR=XCADNR LEFT OUTER
JOIN XKS00 ON KDKDNR=KSKDNR LEFT OUTER JOIN AKZ00 ON KDKDNR=KZKDNR WHERE KDKDNR=' 10001'".
We also should be - to a certain degree - be Unicode aware:
>>> query(u'XKD00', u"KDKDNR LIKE '%18287'")[0]['ort'].encode('utf8')
'G\xc3\xbcnzburg'
Results are cached for 300 seconds unless you set something else via the cachingtime parameter.
"""
# fixup sloppy parameter passing
if isinstance(tables, basestring):
tables = [tables]
if isinstance(grouping, basestring):
grouping = [grouping]
if isinstance(ordering, basestring):
ordering = [ordering]
if isinstance(fields, basestring):
fields = [fields]
if not joins:
joins = []
if not grouping:
grouping = []
if not ordering:
ordering = []
if not fields:
fields = []
tablenames = [_get_tablename(x) for x in tables]
if querymappings == {} and not fields:
raise RuntimeError("Please give fieldnames.")
if querymappings is None and len(fields) != 1:
querymappings = {}
jointables = [table for table, foo, bar in joins]
for table in tables + jointables:
# dubletten = set(querymappings.values()) & set(MAPPINGDIR.get(table, {}).values())
# if dubletten:
# logging.warning('field name clash: %s' % list(dubletten))
querymappings.update(MAPPINGDIR.get(table, {}))
if not fields: # decuce fieldnames from querymappings
fields = querymappings.keys()
if not fields: # still nothing found
raise RuntimeError("can't deduce field names, check fields.py")
args = dict(fields=fields, tablenames=tablenames, tag=ua)
if condition:
args['condition'] = condition
if grouping:
args['grouping'] = grouping
if ordering:
args['ordering'] = ordering
if limit:
args['limit'] = limit
if joins:
# ensure a list of 3-tuples
joins = [(_get_tablename(a), b, c) for (a, b, c) in joins]
args['joins'] = joins
bust_cache = True
if cachingtime > 0:
bust_cache = False
rows = memcache.get('husoftm_query_%r_%r' % (querymappings, args))
if rows:
return rows
start = time.time()
result = execute('sql', args, ua=ua, bust_cache=bust_cache)
rows = hujson.loads(result)
if querymappings:
rows = _rows2dict(fields, querymappings, rows)
else:
rows = [tuple([_fix_field(data, name) for data, name in zip(row, fields)]) for row in rows]
delta = time.time() - start
if delta > 5:
logging.warning("Slow (%.3fs) SQL query in %s", delta, args)
try:
memcache.add(key='husoftm_query_%r_%r' % (querymappings, args),
value=rows, time=cachingtime)
except:
pass # value 'rows' was probably to big for memcache or memcache was offline
return rows
