Flask SQLAlchemy 多级外键 JOIN 查询示例

To perform a multi-level join query using Flask SQLAlchemy, you can use the join() method and specify the join conditions between the tables. Here's an example of how you can join HandleGaochabiaoComparisonResult with HandleGaochabiaoCezhan: python
query = HandleGaochabiaoComparisonResult.query.join(
 HandleGaochabiaoMatchs,
 HandleGaochabiaoMatchs.canzhaos,
 HandleGaochabiaoCezhan
).filter(HandleGaochabiaoComparisonResult.user_id == user_id)

results = query.all()
 In the above example, HandleGaochabiaoComparisonResult is joined with HandleGaochabiaoMatchs using the relationship canzhaos and then joined with HandleGaochabiaoCezhan. You can modify the join conditions according to your specific requirements. Additionally, you can add any necessary filters or additional join conditions using the filter() method. Hope this helps!