def run_q(cnx, q, args, fetch=False, commit=True):
"""
:param cnx: The database connection to use.
:param q: The query string to run.
:param args: Parameters to insert into query template if q is a template.
:param fetch: True if this query produces a result and the function should perform and return fetchall()
:return:
"""
#debug_message("run_q: q = " + q)
ut.debug_message("Q = " + q)
ut.debug_message("Args = ", args)
result = None
try:
cursor = cnx.cursor()
result = cursor.execute(q, args)
if fetch:
result = cursor.fetchall()
if commit:
cnx.commit()
except pymysql_exceptions as original_e:
#print("dffutils.run_q got exception = ", original_e)
raise (original_e)
return result
def add_to_cache(key, value):
"""
:param key: A valid Redis key string.
:param value: A Python dictionary to add to cache.
:return: None
"""
k = key
ut.debug_message("Adding key = ", k)
ut.debug_message("Adding data", value)
r.hmset(k, value)
def compute_key(resource, template, fields):
"""
:param resource: The name of a resource, i.e. database table name.
:param template: A query template for finding a resource in a table.
:param fields: List of fields to retrieve, e.g. project clause.
:return: A valid Redis key that for storing/retrieving a map from the Redis cache.
"""
ut.debug_message("Resource = ", resource)
ut.debug_message("Template = ", template)
ut.debug_message("Fields = ", fields)
t = None
f = None
if template is not None:
"""
Convert the query template to a string form of p1=v1,p2=v2, ...
"""
# print("Items = ", template.items())
t = template.items()
# print("t = ", t)
t = tuple(t)
# print("t = ", t)
sorted(t, key=itemgetter(1))
ts = [str(e[0]) + "=" + str(e[1]) for e in t]
t = ",".join(ts)
if fields is not None:
"""
Convert a fields list into a string of the form f=f1,f2,...
"""
f = sorted(fields)
f = "f=" + (",".join(f))
if f is not None or t is not None:
"""
There is a convention in Redis that a collection of resources if of the form
collection_name:key_value. If there is a sub-key representing the template or fields selector,
add a ':' to the end of the resource name.
"""
result = resource + ":"
else:
result = resource
# Add template string to key if it exists.
if t is not None:
result += t
# If there is a fields list, add it to the key. Add a "," to separate from template string
# if there is a template string.
if f is not None and t is not None:
result += "," + f
elif f is not None and t is None:
result += f
return result
