Python Query database Data nonetype error

When you debug a MySQL database in Python, there is no problem when testing a single query statement.

The execution process is as follows:

1, by the connection object Conn gets to a cursor. cur = conn.cursor ()

2. Execute the SQL statement. Count = Cur.execute (SQL)

3, read the data. result = Cur.fetchone () #获取一条

4, close the cursor, connect. Cur.close () Conn.close ()

This query process executes once without problems, but it occurs when multiple executions occur, Nonetype.

or CharSet = Db.character_set_name ()

_mysql_exceptions. Interfaceerror: (0, ")

and other errors.

The reason is that the defined Conn Connection object is a global variable, and when the first execution is completed, the query is finally changed,

Performs a conn.close () close operation that causes the Conn connection object to close. When you use a Change object again,

The error shown in title appears.

Python Query database Data nonetype error