from sqlalchemy import create_engine, MetaData, Column from sqlalchemy.dialects.mysql import INTEGER, DOUBLE, BIGINT, VARCHAR, CHAR, TEXT, DATETIME from sqlalchemy.ext.declarative import declarative_base from sqlalchemy.orm import sessionmaker # 创建数据库引擎,ps:这里并没有连接具体数据库 engine = ...
#解析sql语句中的字段和表名, 参考 https://www.robin.eu.org/programming/extracting-table-and-column-names-from-sql-query/ def sqlparse(sql_str): sql_str = sql_str.replace('SELECT', 'select') sql_str = sql_str.replace('WHERE', 'where') sql_str = sql_str.replace('FROM', 'from')...
# 查询information_schema获取列名defget_column_names(table_name):conn=connect_to_database()cursor=conn.cursor()# 构造SQL语句sql=f"SELECT COLUMN_NAME FROM information_schema.COLUMNS WHERE TABLE_NAME = '{table_name}'"# 执行SQL语句cursor.execute(sql)# 获取结果result=cursor.fetchall()# 提取列名co...
mysql> insert into stu_info (name,age,register_date) values ("LiuYouyuan",20,"2015-9-1"); Query OK, 1 row affected (0.05 sec) mysql> select * from stu_info; +---+---+---+---+ | stu_id | name | age | register_date | +---+---+---+---+ | 1 | LiuYouyuan | 20...
本文主要介绍使用pandas.read_sql_query()一些常用操作示例demo代码。 1、测试数据库连接问题代码 def test_connectable_issue_example(self): # This tests the example raised in issue # https://github.com/pydata/pandas/issues/10104 def foo(connection): query = 'SELECT test_foo_data FROM test_foo_...
name, column.type) 二、Python 从数据库读取数据从数据库读取数据是 Python 的另一个重要功能。我们可以使用 SQLAlchemy 的查询功能来执行 SQL 查询并获取结果。以下是一个示例,展示如何从 “users” 表中读取所有用户:2.1 执行查询并获取结果```pythonfrom sqlalchemy.orm import sessionmaker, loadonlyfrom sql...
insp=inspect(engine)insp.get_table_names()[Out:]['apartment','building','student','inspector','manager','managercontact'] 2.1 查看默认数据库的一个表格 fromsqlalchemy.sqlimporttextsql='''SELECT * FROM building;'''withengine.connect().execution_options(autocommit=True)asconn:query=conn.execute...
Restart R_SERVER. On SQL Server, you can restart SQL Server Launchpad Service. หมายเหตุ If you are running the SQL Server 2019 (15.x) on Linux, edit or create.bash_profilein your user home directory, adding the lineexport MKL_CBWR="AUTO". Ex...
# 需要导入模块: from stetl.postgis import PostGIS [as 别名]# 或者: from stetl.postgis.PostGIS importget_column_names[as 别名]classPostgresDbInput(SqlDbInput):""" Input by querying records from a Postgres database. Input is a query, like SELECT * from mytable. ...
> CREATE FUNCTION area(x DOUBLE, y DOUBLE) RETURNS DOUBLE RETURN x * y; -- Use a SQL function in the SELECT clause of a query. > SELECT area(c1, c2) AS area FROM t; 0.0 2.0 -- Use a SQL function in the WHERE clause of a query. > SELECT * FROM t WHERE area(c1, c2) >...