def put(redcap_env, projectid, recordid, attrname, attrval):
'''Put a new name-value pair into the store. It will create
a new version if an older one already exists. Note: returns empty tuple.'''
stmt = '''insert into eav (env, projectid, recordid, attrname, attrval)
values (%s, %s, %s, %s, %s) '''
vals = redcap_env, projectid, recordid, attrname, attrval
rslt = db.go(db_spec, stmt, vals, commit=True)
return rslt
def exists(redcap_env, projectid, recordid, attrname):
qy1 = '''select count(*) as ttl
from eav
where env = %s and projectid = %s
and recordid = %s
and attrname = %s '''
vals = redcap_env, projectid, recordid, attrname
ttl = db.go(db_spec, qy1, vals, db.ReturnKind.SINGLEVAL)
if ttl > 0: return True
else: return False
def get_latest_value(redcap_env, projectid, recordid, attrname):
'''Will return empty string if it can't find anything.'''
qy2 = '''select ifnull(attrval, 'nil') as attrval
from eav
where env = %s and projectid = %s
and recordid = %s
and attrname = %s
order by ts DESC -- put latest value in first row '''
vals = redcap_env, projectid, recordid, attrname
# Grab the first value in the first row
rslt = db.go(db_spec, qy2, vals, db.ReturnKind.SINGLEVAL)
return rslt