小白对于oracle 参数化SQL查询语句的提问

Question

select * from table where a=：a and b=:b and c=:c  这样一个查询语句

如果三个参数中的:c在没有值的情况下想要实现 select* from table where a=1 and b=2的效果，这个查询语句应该怎么写？

Answer 1

if c is None:
    sql = select * from table where a=1 and b=2
else:
    sql = select * from table where a=：a and b=:b and c=:c