sqlalchemy 查询：结果列名

Posted 2023-04-12

【中文标题】sqlalchemy 查询：结果列名

【英文标题】：sqlalchemy query: result column names

【发布时间】：2016-02-16 13:59:19

【问题描述】：

我有一个名为 DevicesGpsTelemetry 的模型（使用声明式基础声明）。我这样查询：

models = session.query(
    DevicesGps.ReceivedDateUtc, 
    DevicesGps.ReceivedTimeUtc,   
    DevicesGps.Latitude,                                 
    DevicesGps.Longitude)

它呈现为：

    SELECT   
    devices_gps."ReceivedDateUtc" AS "devices_gps_ReceivedDateUtc", 
    devices_gps."ReceivedTimeUtc" AS "devices_gps_ReceivedTimeUtc", 
    devices_gps."Latitude" AS "devices_gps_Latitude", 
    devices_gps."Longitude" AS "devices_gps_Longitude" 
        FROM devices_gps

我的问题：如何将 AS 语句之后的名称（如 "gps_telemetry_ReceivedDateUtc"）更改为我想要的名称？

背景：这些名字对我来说很重要，因为我用这个查询 pandas.read_sql 并且这些名字变成了 DataFrame 的列名

【参考方案1】：

在每列后添加.label('desired_name')。在你的情况下，它看起来像

models = session.query(
    DevicesGps.ReceivedDateUtc.label("gps_telemetry_ReceivedDateUtc"), 
    DevicesGps.ReceivedTimeUtc.label("gps_telemetry_ReceivedTimeUtc"),   
    DevicesGps.Latitude.label("gps_telemetry_Latitude"),                                 
    DevicesGps.Longitude.label("gps_telemetry_Longitude")
)

【讨论】：

谢谢。在文档中不知何故错过了这一点