python sqlparse_使用sqlparse解析表名、超级强大、支持子查询、左联接等,tablename,leftjoin...
import sqlparse
from sqlparse.sql import IdentifierList, Identifier
from sqlparse.tokens import Keyword, DML
# 支持的join方式
ALL_JOIN_TYPE = ('LEFT JOIN', 'RIGHT JOIN', 'INNER JOIN', 'FULL JOIN', 'LEFT OUTER JOIN', 'FULL OUTER JOIN')
def is_subselect(parsed):
"""
是否子查询
:param parsed:
:return:
"""
if not parsed.is_group:
return False
for item in parsed.tokens:
if item.ttype is DML and item.value.upper() == 'SELECT':
return True
return False
def extract_from_part(parsed):
"""
提取from之后模块
:param parsed:
:return:
"""
from_seen = False
for item in parsed.tokens:
if from_seen:
if is_subselect(item):
for x in extract_from_part(item):
yield x
elif item.ttype is Keyword:
from_seen = False
continue
else:
yield item
elif item.ttype is Keyword and item.value.upper() == 'FROM':
from_seen = True
def extract_join_part(parsed):
"""
提交join之后模块
:param parsed:
:return:
"""
flag = False
for item in parsed.tokens:
if flag:
if item.ttype is Keyword:
flag = False
continue
else:
yield item
if item.ttype is Keyword and item.value.upper() in ALL_JOIN_TYPE:
flag = True
def extract_table_identifiers(token_stream):
for item in token_stream:
if isinstance(item, IdentifierList):
for identifier in item.get_identifiers():
yield identifier.get_name()
elif isinstance(item, Identifier):
yield item.get_name()
elif item.ttype is Keyword:
yield item.value
def extract_tables(sql):
"""
提取sql中的表名(select语句)
:param sql:
:return:
"""
from_stream = extract_from_part(sqlparse.parse(sql)[0])
join_stream = extract_join_part(sqlparse.parse(sql)[0])
return list(extract_table_identifiers(from_stream)) + list(extract_table_identifiers(join_stream))
print(extract_tables("select x1, x2 from a left join b on a.id = b.id right join c on c.id = a.id"))
print(extract_tables("select x1, x2 from (select x1, x2 from (select x1, x2 from a)) left join b on a.id=b.id"))