Python SQLAlchemy:使用标签进一步筛选查询
我有一个查询,它生成一个id,后跟一个计数。我只想获取计数为N的行。我尝试了下面的代码,但得到了“错误:列“cert\u count”不存在”。我猜我用错标签了Python SQLAlchemy:使用标签进一步筛选查询,python,sqlalchemy,Python,Sqlalchemy,我有一个查询,它生成一个id,后跟一个计数。我只想获取计数为N的行。我尝试了下面的代码,但得到了“错误:列“cert\u count”不存在”。我猜我用错标签了 cust_cert_counts = db.session.query( CustomerCertAssociation.customer_id, func.count(CustomerCertAssociation.certification_id).label('cert_count')).filter( C
cust_cert_counts = db.session.query(
CustomerCertAssociation.customer_id,
func.count(CustomerCertAssociation.certification_id).label('cert_count')).filter(
CustomerCertAssociation.certification_id.in_(cert_ids)).group_by(
CustomerCertAssociation.customer_id)
cust_cert_counts.filter('cert_count=2').all()
您不能像这样对别名列进行筛选:
SELECT 1 AS foo WHERE foo = 1;
您必须将其嵌套在子查询中:
SELECT * FROM (SELECT 1 AS foo) bar WHERE bar.foo = 1;
对于您的特定示例,您必须执行以下操作:
subq = cust_cert_counts.subquery()
db.session.query(subq).filter(subq.c.cert_count == 2)