I am using postgreSQL queries. I want to extract all information from a SQL query, for example
sql = " select d_year, s_nation, p_category, sum(lo_revenue - lo_supplycost) as profit from DATES, CUSTOMER, SUPPLIER, PART, LINEORDER where lo_custkey = c_custkey and lo_suppkey = s_suppkey and lo_partkey = p_partkey and lo_orderdate = d_datekey and c_region = 'AFRICA' and s_region = 'AFRICA' and (d_year = 1996 or d_year = 1997) and (p_mfgr = 'MFGR#2' or p_mfgr = 'MFGR#4') group by d_year, s_nation, p_category order by d_year, s_nation, p_category "
I want to get all tables concerned, all selection predicate, and all join predicate, group by part, and order by part.
I used sqlparse
and I found a way to get only the tables concerned.
Is there any examples of how to extract this information?
This algorithm gives the exact element between each keyword. I used sqlparse
parsed = sqlparse.parse(sql)
stmt = parsed[0]
from_seen = False
select_seen = False
where_seen = False
groupby_seen = False
orderby_seen = False
for token in stmt.tokens:
if select_seen:
if isinstance(token, IdentifierList):
for identifier in token.get_identifiers():
print("{} {}\n".format("Attr = ", identifier))
elif isinstance(token, Identifier):
print("{} {}\n".format("Attr = ", token))
if from_seen:
if isinstance(token, IdentifierList):
for identifier in token.get_identifiers():
print("{} {}\n".format("TAB = ", identifier))
elif isinstance(token, Identifier):
print("{} {}\n".format("TAB = ", token))
if orderby_seen:
if isinstance(token, IdentifierList):
for identifier in token.get_identifiers():
print("{} {}\n".format("ORDERBY att = ", identifier))
elif isinstance(token, Identifier):
print("{} {}\n".format("ORDERBY att = ", token))
if groupby_seen:
if isinstance(token, IdentifierList):
for identifier in token.get_identifiers():
print("{} {}\n".format("GROUPBY att = ", identifier))
elif isinstance(token, Identifier):
print("{} {}\n".format("GROUPBY att = ", token))
if isinstance(token, Where):
select_seen = False
from_seen = False
where_seen = True
groupby_seen = False
orderby_seen = False
for where_tokens in token:
if isinstance(where_tokens, Comparison):
print("{} {}\n".format("Comparaison = ", where_tokens))
elif isinstance(where_tokens, Parenthesis):
print("{} {}\n".format("Parenthesis = ", where_tokens))
# tables.append(token)
if token.ttype is Keyword and token.value.upper() == "GROUP BY":
select_seen = False
from_seen = False
where_seen = False
groupby_seen = True
orderby_seen = False
if token.ttype is Keyword and token.value.upper() == "ORDER BY":
select_seen = False
from_seen = False
where_seen = False
groupby_seen = False
orderby_seen = True
if token.ttype is Keyword and token.value.upper() == "FROM":
select_seen = False
from_seen = True
where_seen = False
groupby_seen = False
orderby_seen = False
if token.ttype is DML and token.value.upper() == "SELECT":
select_seen = True
from_seen = False
where_seen = False
groupby_seen = False
orderby_seen = False