问题

我有一个数据库，当我查询一张表时，我得到了67个结果。SQL语句是：

SELECT lower(UserName) from Participants ;

我尝试连接到数据库，没有连接错误。

def db_connect ():
try:
cnx = mysql.connector.connect(user=db_user, password=db_password,host=db_host,database=db_name)
return cnx
except mysql.connector.Error as err:
if err.errno == errorcode.ER_ACCESS_DENIED_ERROR:
print("你的用户名或密码有问题")
elif err.errno == errorcode.ER_BAD_DB_ERROR:
print("数据库不存在")
else:
print(err)

def main():
cnx = db_connect()
cursor = cnx.cursor()
query = ("SELECT lower(UserName) from Participants ;")
cursor.execute(query)
print(cursor.rowcount)

<details>
<summary>英文:</summary>

I have a DB and when I query a table I get 67 results. The SQL is: 

SELECT lower(UserName) from Participants ;

I try to connect to the DB, and I get no connection errors.

def db_connect ():
try:
cnx = mysql.connector.connect(user=db_user, password=db_password,host=db_host,database=db_name)
return cnx
except mysql.connector.Error as err:
if err.errno == errorcode.ER_ACCESS_DENIED_ERROR:
print("Something is wrong with your user name or password")
elif err.errno == errorcode.ER_BAD_DB_ERROR:
print("Database does not exist")
else:
print(err)

def main():
cnx = db_connect()
cursor = cnx.cursor()
query = ("SELECT lower(UserName) from Participants ;")
cursor.execute(query)
print(cursor.rowcount)

It prints out -1 for rowcount. The connection to the DB appears to be working, the SQL is a simple query...

</details>


# 答案1
**得分**: 1

尝试在`print(cursor.rowcount)`之前添加`cursor.fetchall()`。

<details>
<summary>英文:</summary>

 - Try adding `cursor.fetchall()` before the `print(cursor.rowcount)` 

</details>