#池中没有线程最多等待的时间,否则报错pool_recycle=-1#多久之后对线程池中的线程进行一次连接的回收(重置))#3 通过engine获得conn,cursorconn = engine.raw_connection()#拿到连接对象cursor =conn.cursor()#4 具体操作cursor.execute('select * from article limit 10')print(cursor.fetchall())...
GROUP BY: GROUP BY is a clause in SQL that is only used with aggregate functions. It is used along with the SELECT statement to arrange identical data into groups. SELECT COUNT(*) FROM table_name GROUP BY column_name; 1. 2. 3. Output: Execution of this order will result in grouping ...
8. INSERT INTO t_col_row VALUES (2, 'v12', 'v22', NULL); 9. INSERT INTO t_col_row VALUES (3, 'v13', NULL, 'v33'); 10. INSERT INTO t_col_row VALUES (4, NULL, 'v24', 'v34'); 11. INSERT INTO t_col_row VALUES (5, 'v15', NULL, NULL); 12. INSERT INTO t_col...
id, row.nick_name, row.phone)) return result 上述代码执行后生成SQL如下: SELECT ... FROM ym_user WHERE id > 100 AND id < 200 AND nick_name LIKE '%飞%' OR phone IN ('17408049453','15795343139','13189106944') 4.新增数据 4.1 新增单条 def addOne(): """ 新增单条数据 """ row =...
我试图使用SQLAlchemy 1.4查询Oracle数据库: SELECT MAX(:created_date) FROM EXAMPLE_TABLE 这应该返回某种类型的datetime对象。当我使用SQLAlchemy执行此代码(大致)时,它决定返回:created_date参数的值。 from sqlalchemy import create_engine as SQLAlchemyEngine from sqlalchemy import text as SQLAlchemyText with...
engine= create_engine("mysql+pymysql://root:123456@127.0.0.1:3306/db1", max_overflow=5)#生成一个sqlorm基类Base =declarative_base()#创建表,一个类代表一张表classUsers(Base):#添加表结构__tablename__='t_u_users'#创建表名#创建id字段,类型是int,主键且进行自增id = Column(Integer, primary...
emails,lambdarow: row['email'], ) 开发者ID:lablup,项目名称:backend.ai-manager,代码行数:25,代码来源:user.py 示例2: check_credential ▲点赞 6▼ # 需要导入模块: import sqlalchemy [as 别名]# 或者: from sqlalchemy importselect[as 别名]defcheck_credential(dbpool, domain: str, email: str...
此缓冲区的最大大小可以通过 Connection.execution_options.max_row_buffer 执行选项受到影响: with engine.connect() as conn: with conn.execution_options(stream_results=True, max_row_buffer=100).execute( text("select * from table") ) as result: for row in result: print(f"{row}") 虽然...
ret=engine.execute("select * from t1;")# print(dir(engine))# print(ret.fetchone())print(ret.fetchall()) 五、ORM 的基本操作 ORM 流程 ORM 操作的流程是,一个 Engine 使用 Schema Type 创建一个特定的结构对象,之后通过 SQL Expression Language 将该对象转换成 SQL 语句, 接着使用 ConnectionPling...
[LIMIT {[offset,] row_count}] -- LIMIT限制查询条数 offset(偏移量,从哪开始), row_count(查询的条数) -- 条件查询 SELECT * FROMstudentWHEREsex='男'; SELECTid,name,nicknameFROMstudentWHEREsex='男' ORDER BYidDESC; -- 修改(更新) ...