sqlalchemy2 学习进度select完成

sqlalchemy_20/db.py

@@ -1,4 +1,4 @@
-from sqlalchemy import create_engine, text, insert, update, select, delete, engine_from_config, or_, and_, func
+from sqlalchemy import create_engine, text, insert, update, select, delete, engine_from_config, or_, and_, func, any_
 from sqlalchemy.orm import Session, sessionmaker
 import configparser
 import sys
@@ -246,18 +246,54 @@ insert_data2 = {'name': 'sql2_test2', 'password': 'pwd2'}
 # query_result = db_session.execute(sql_stmt).scalar()
 # print(query_result)
 
-
+# sqlalchemy1.4:
 # try:
 #     result = session.query(User).filter(User.id > 1).one()  # one 当仅查询到一个结果时返回，否则抛出异常
 # except Exception as e:
 #     print(e)
-# result = session.query(User).filter(User.id == 1).one_or_none()  # one_or_none 当查询结果仅一条时显示返回结果，当没有结果时返回None，否则抛出异常
-# result = session.query(User).filter(User.id == 1).scalar()  # 调用one方法，并在成功时返回行的第一列
-# result = session.query(User).filter(User.id > 1).group_by(User.password)
-# result = session.query(func.max(User.id)).all()  # func.max
-# print(result[0].name, result[0].password)
-# print(result)  # 定义 __repr__ 后可以打印
+# try:
+#     sql_stmt = select(User).where(User.id > 2)
+#     query_result = db_session.execute(sql_stmt).one()
+# except Exception as e:
+#     print(e)
+
+# sqlalchemy1.4: session.query(User).filter(User.id == 1).one_or_none()
+# try:
+#     # sql_stmt = select(User).where(User.id >= 1)  # 多结果
+#     # sql_stmt = select(User).where(User.id == 1)  # 一个结果
+#     sql_stmt = select(User).where(User.id == 100)  # 无结果
+#     query_result = db_session.execute(sql_stmt).one_or_none()
+#     print(query_result)
+# except Exception as e:
+#     print(e)
+
+# sqlalchemy1.4: session.query(User).filter(User.id == 1).scalar()
+# sql_stmt = select(User).where(User.id >= 1)
+# query_result = db_session.execute(sql_stmt).scalar()
+# print(query_result.name)
+
+# sqlalchemy1.4: session.query(User).filter(User.id > 1).group_by(User.password)
+# sql_stnt = select(User.password).where(User.id > 1).group_by(User.password)
+# query_result = db_session.execute(sql_stnt).scalars()
+# for row in query_result:
+#     print(row)
+
+# sqlalchemy1.4: session.query(func.max(User.id)).all()
+# sql_stmt = select(func.max(User.id))
+# query_result = db_session.execute(sql_stmt).scalars()
+# for row in query_result:
+#     print(row)
 
+# func
+# func.now()
+# func.current_timestamp()
+# func.current_date()
+# func.current_time()
+# func.min()
+# func.localtime()
+# func.localtimestamp()
+# func.random()
+# func.sum()
 
 # select all scalars
 # result = db_session.execute(select(User)).scalars().all()  # [<1 name:rogersun>, <2 name:honeyhoney>, <3 name:haha>]