SQLAlchemy：ProgrammingError 但打印的 SQL 语句有效？

Question

我正在尝试使用 SQLAlchemy 对每个月在 table 中找到的行数进行分组和计数。

函数如下：

def query_testing(
    session: scoped_session,
    from_date: datetime,
    to_date: datetime,
):
    qry = (
        session.query(
            func.count(U4.index).label("count"),
            func.dateadd(
                text("month"),
                func.datediff(text("month"), 0, U4.arrival),
                0,
            ).label("received"),
        )
        .filter(
            cast(U4.arrival, Date) >= from_date,
            cast(U4.arrival, Date) <= to_date,
        )
        .group_by(
            func.dateadd(
                text("month"),
                func.datediff(text("month"), 0, U4.arrival),
                0,
            ),
        )
        .order_by(
            func.dateadd(
                text("month"),
                func.datediff(text("month"), 0, U4.arrival),
                0,
            )
        )
    )

不幸的是，使用 qry.all() 执行查询会导致编程错误：

[Microsoft][ODBC Driver 17 for SQL Server][SQL Server]Column 'u4erp.received' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.

当我 print(qry) 语句并尝试手动执行生成的 SQL 时，语句有效（在手动将 ? 更改为其预期值之后）。打印语句如下：

SELECT
    count(u4erp.[index]) AS count,
    dateadd(MONTH, datediff(MONTH, 0, u4erp.received), 0) AS received
FROM
    u4erp
WHERE
    CAST(
        u4erp.received AS DATE
    ) >= '2020-01-01'
    AND CAST(
        u4erp.received AS DATE
    ) <= '2021-12-31'
GROUP BY
    dateadd(MONTH, datediff(MONTH, 0, u4erp.received), 0)
ORDER BY
    dateadd(MONTH, datediff(MONTH, 0, u4erp.received), 0)

是什么导致打印的 SQL 语句有效，但在使用 SQLAlchemy 时引发编程错误？我该如何解决？

Answer 1

我使用 text.

为我的特定用例找到了解决方法

def query_testing(
    session: scoped_session,
    from_date: datetime,
    to_date: datetime,
):
    qry = (
        session.query(
            func.count(U4.index).label("count"),
            text(
                "DATEADD(MONTH, DATEDIFF(MONTH, 0, "
                "u4erp.received), 0) AS received"
            ),
        )
        .filter(
            cast(U4.arrival, Date) >= from_date,
            cast(U4.arrival, Date) <= to_date,
        )
        .group_by(
            text(
                "DATEADD(MONTH, DATEDIFF(MONTH, 0, "
                "u4erp.received), 0)"
            ),
        )
        .order_by(
            text(
                "DATEADD(MONTH, DATEDIFF(MONTH, 0, "
                "u4erp.received), 0)"
            ),
        )
    )

SQLAlchemy：ProgrammingError 但打印的 SQL 语句有效？

SQLAlchemy: ProgrammingError but the printed SQL statement works?

python

sql

sql-server

sqlalchemy