Question

我有以下代码将数据（detector_id，video_id，score）插入表得分（如果它不存在），如果它存在，则将得分添加到其现有值：

from flask import Flask
from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = SQLALCHEMY_DATABASE_URI
db = SQLAlchemy(app)

query = "DO $$ BEGIN UPDATE "+table_score+" SET score = score + \'"+ concept_score +"\' " + \
        "WHERE detector_id = \'"+ detector_id +"\' AND video_id = \'"+video_id+"\'; " + \
        "IF NOT FOUND THEN INSERT INTO "+table_score+" VALUES (\'"+detector_id+"\', \'"+video_id+"\', "+concept_score+"); " + \
        "END IF; END $$;"
result = db.engine.execute(query)

这相当于以下内容，当我在pgAdmin中执行它时可以正常工作：

DO $$ BEGIN 
    UPDATE score SET score = score + SCORE_VALUE
        WHERE detector_id = 'DETECTOR_ID' AND video_id = 'VIDEO_ID';
    IF NOT FOUND THEN 
        INSERT INTO score VALUES ('DETECTOR_ID', 'VIDEO_ID', SCORE_VALUE);
    END IF; 
END $$

但是，如果我尝试执行Python代码，它不会添加任何内容。我也没有收到任何错误消息。其他查询工作正常，所以它不是我的数据库连接的问题。当我尝试输出list(result)时，它会返回：This result object does not return rows.

如果我执行print query，并在pgAdmin中运行该字符串，则可以正常工作。但是，db.engine.execute(query)运行它不会。其他查询（例如SELECT * FROM score s WHERE s.detector_id ='DETECTOR_ID';）可以与db.engine.execute(query)一起使用。这是否与DO $$..声明有关？

以下工作正常，但似乎过分：

query = "SELECT * FROM "+table_score+" s WHERE s.detector_id = \'"+ detector_id +"\' AND s.video_id = \'"+video_id+"\';"
result = db.engine.execute(query)
if len(list(result)) > 0:
    query = "UPDATE "+table_score+" SET score = score + \'"+ concept_score +"\' WHERE detector_id = \'"+ detector_id +"\' AND video_id = \'"+video_id+"\';"
else:
    query = "INSERT INTO "+table_score+" VALUES (\'"+detector_id+"\', \'"+video_id+"\', "+concept_score+");"
result = db.engine.execute(query)

Flask-SQLAlchemy Postgres查询不插入行

0 个答案: