“CREATE ... 语句不允许在多语句事务中"使用pyodbc时 [英] "CREATE ... statement not allowed within multi-statement transaction" when using pyodbc

问题描述

我正在尝试使用 pyodbc 创建 SQL Server 数据库.

I'm trying to create a SQL Server database using pyodbc.

import pyodbc 
server = 'AMR112\NAMED1' 
database = 'msdb' 
username = '' 
password = 'mypassword' 
abcd='yes' 
ghi='False' 
#driver = '{/usr/local/lib/libtdsodbc.so}' #for linux of windows 
driver= '{ODBC Driver 13 for SQL Server}' 
cnxn = pyodbc.connect('DRIVER='+driver+';PORT=1433;SERVER='+server+??';PORT=1443;DATABASE??='+database+';UID='+??username+';PWD='+ password+';trusted_connection='+ abcd+'; autocommit='+ ghi) cursor = cnxn.cursor() 
cursor.execute("create database dbafgh") 
row = cursor.fetchone() 
if row: 
    print row 
cursor.close()

它因这个错误而失败

在多语句事务中不允许使用 CREATE DATABASE 语句

CREATE DATABASE statement not allowed within multi-statement transaction

失败是因为 .execute 方法启动了一个事务并且 CREATE DATABASE 不能在一个事务中运行.

It fails because the .execute method starts a transaction and CREATE DATABASE cannot be run within a transaction.

那么还有其他方法可以使用 python 执行 CREATE DATABASE 命令吗?

So is there any other way to execute a CREATE DATABASE command using python?

推荐答案

在建立连接时，pyodbc 根据 Python 的 DB-API 规范默认为 autocommit=False.因此，当第一条 SQL 语句被执行时，ODBC 开始一个数据库事务，该事务一直有效，直到 Python 代码执行 .commit() 或 .rollback()连接.

When establishing a connection, pyodbc defaults to autocommit=False in accordance with Python's DB-API spec. Therefore when the first SQL statement is executed, ODBC begins a database transaction that remains in effect until the Python code does a .commit() or a .rollback() on the connection.

SQL Server 不允许在这样的事务中执行 CREATE DATABASE，因此在发出这样的语句之前，我们需要在 autocommit 模式下进行连接.这可以在打开连接时完成...

SQL Server does not allow CREATE DATABASE to be executed within such a transaction, so we need to have the connection in autocommit mode before issuing such statements. That can be accomplished when the connection is opened ...

conn = pyodbc.connect(conn_str, autocommit=True)

... 或者如果连接已经建立，则切换到 autocommit 模式:

... or by switching to autocommit mode if the connection is already established:

conn = pyodbc.connect(conn_str)  # autocommit=False by default
# ...
conn.autocommit = True
conn.execute("CREATE DATABASE MyNewDatabase")

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