sqlalchemy simple example of `sum`, `average`, `min`, `max`
For sqlalchemy, Who can gently give simple examples of SQL functions like sum, average, min, max, for a column (score in the following as an example).
As for this mapper:
class Score(Base): #... name = Column(String) score= Column(Integer) #...
Answers
See SQL Expression Language Tutorial for the usage. The code below shows the usage:
from sqlalchemy.sql import func qry = session.query(func.max(Score.score).label("max_score"), func.sum(Score.score).label("total_score"), ) qry = qry.group_by(Score.name) for _res in qry.all(): print _res
Need Your Help
How to parse positional arguments with leading minus sign (negative numbers) using argparse
I would like to parse a required, positional argument containing a comma-separated list of integers. If the first integer contains a leading minus ('-') sign, argparse complains:Dynamic Java Bytecode Manipulation Framework Comparison
java-bytecode-asm javassist cglib bytecode-manipulation jvm-bytecode
There are some frameworks out there for dynamic bytecode generation, manipulation and weaving (BCEL, CGLIB, javassist, ASM, MPS). I want to learn about them, but since I don't have much time to kno...