在 sqlalchemy/marshmallow 中，我们如何通过由左联表提供的 `.group_by()` 来实现 `.count()`？ 模型架构应用

如何解决在 sqlalchemy/marshmallow 中，我们如何通过由左联表提供的 `.group_by()` 来实现 `.count()`？ 模型架构应用

我已经尝试了我能想到的几乎所有变体，但仍然找不到flask_sqlalchemy、marshmallow_sqlalchemy的这种“组合”的答案。当我到达端点时，我设法获得了大量“无错误”响应，但没有一个给出我需要的响应（其中 severity 来自“左关节”表，而 {{1 }} 是每个 Report 的 count 每个值的数量的计数：

severity

这是我的设置/配置：

模型

[
  {'study': '11111','project': 'AAAAA','details': [
    {'severity': 'warning','count': 65},{'severity': 'error','count': 55}
  ]},{'study': '22222','count': 21},'count': 5}
  ]},{'study': '55555','project': 'BBBBB','count': 102},'count': 11}
  ]}
]

架构

from flask_sqlalchemy import SQLAlchemy
db = SQLAlchemy(app)

class Report(db.Model):
    __tablename__ = 'report'
    id = db.Column(db.Integer,primary_key=True)
    project = db.Column(db.String)
    study = db.Column(db.String)
    details= db.relationship("Detail",back_populates="report")

class Detail(db.Model):
    __tablename__ = 'detail'
    id = db.Column(db.Integer,primary_key=True)
    domain = db.Column(db.String(2))
    record = db.Column(db.SMALLINT)
    count = db.Column(db.Integer)
    severity = db.Column(db.String)

    report_id = db.Column(db.Integer,db.ForeignKey('report.id'))
    report = db.relationship("Report",back_populates="details")

应用

from marshmallow_sqlalchemy import SQLAlchemyAutoSchema,SQLAlchemySchema
from marshmallow_sqlalchemy.fields import fields

class ReportSchema(SQLAlchemyAutoSchema):
    class Meta:
        model = Report
    details = ma.Nested(DetailSchema,many=True)

class DetailSchema(SQLAlchemyAutoSchema):
    class Meta:
        model = Detail

上面给我的输出

它似乎显示了我期望的带有计数和合并的原始 SQL...

import connexion
basedir = os.path.abspath(os.path.dirname(__file__))
app = connex_app.app
app.config["SQLALCHEMY_DATABASE_URI"] = db_path
app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False

reports_schema = ReportSchema(many=True)

@connex_app.route('/api/reports_summary')
def reports_starburst():
    reports = db.session.query(Report.project,Report.study,Detail.severity,func.count(Detail.severity).label('SeverityCount')) \
        .join(Detail).group_by(Report.id).order_by(Report.study,'SeverityCount')
    print("SQL QUERY IS: ",reports)
    result = reports_schema.dump(reports)
    print("RESULT RECEIVED: ",result )
    return {"reports": result}

...但收到的结果总是显示 SQL QUERY IS: SELECT report.project AS report_project,report.study AS report_study,detail.severity AS detail_severity,count(detail.severity) AS "SeverityCount" FROM report JOIN detail ON report.id = detail.report_id GROUP BY report.id ORDER BY report.study,"SeverityCount" （如果我从架构中删除 details: []，则根本不显示）...

default=[],