SQLite 数据库到 Python 字典使用 SQL SELECT 语句

Question

已经搜索了好几天了。请帮忙。我有一个 SQL 查询：

SELECT
WorkList, RecordStatus, COUNT(*) as QTY
FROM worklist_reports
WHERE WorkList IS NOT NULL
GROUP BY WorkList, RecordStatus

哪个returns:

| WorkList | RecordStatus | QTY |
| -------- | ------------ | ----|
|ADM       |Closed        |41   |
|ADM       |Open          |1    |
|BIL       |Closed        |16   |
|BIL       |Hold          |1    |
|BIL       |Open          |2    |

我需要为 RecordStatus 的可能值创建新列，这样我就可以将结果 table 折叠成这样：

| WorkList | Open | Closed | Hold |
| -------- | ---- | ------ | ---- |
|ADM       |1     |41      |0     |
|BIL       |2     |16      |1     |

最终的数据格式将是 python 字典列表：

data = [
    {'x': 'ADM', 'open': 1, 'closed': 41, 'hold': 0}, 
    {'x': 'BIL', 'open': 2, 'closed': 16, 'hold': 1}
]

我可以根据查询结果创建字典。我只需要知道正确的 SQL 语句来格式化查询结果。

任何帮助将不胜感激！

Answer 1

为此，您只需要按 WorkList 分组并使用条件聚合：

SELECT WorkList, 
       SUM(RecordStatus = 'Open') AS Open,
       SUM(RecordStatus = 'Closed') AS Closed,
       SUM(RecordStatus = 'Hold') AS Hold
FROM worklist_reports
WHERE WorkList IS NOT NULL
GROUP BY WorkList;

Answer 2

您也可以保持查询不变，然后使用 pandas 将其转换为您喜欢的记录列表

import pandas as pd

df = pd.DataFrame({
    "WorkList": ["ADM", "ADM", "BIL", "BIL", "BIL"],
    "RecordStatus": ["Closed", "Open", "Closed", "Hold", "Open"],
    "QTY": [41, 1, 16, 1, 2]
})

list_records = df.pivot(
    index="WorkList", columns="RecordStatus", values="QTY"
).fillna(0).astype(int).reset_index().to_dict(orient='records')

list_records
[{'WorkList': 'ADM', 'Closed': 41, 'Hold': 0, 'Open': 1}, {'WorkList': 'BIL', 'Closed': 16, 'Hold': 1, 'Open': 2}]

SQLite 数据库到 Python 字典使用 SQL SELECT 语句

SQLite Database to Python Dictionary using SQL SELECT statement

python

sql

sqlite

dictionary

group-by