def get_processed_files(util: MySQLUtil, db_name, tb_name, tb_cols):如何调用这个函数
时间: 2024-05-05 12:16:32 浏览: 9
需要先导入MySQLUtil模块,并创建一个MySQLUtil对象,然后调用get_processed_files()函数并传入相应的参数,例如:
```
from MySQLUtil import MySQLUtil
# 创建MySQLUtil对象
util = MySQLUtil('localhost', 'root', 'password')
# 调用get_processed_files()函数
db_name = 'mydatabase'
tb_name = 'mytable'
tb_cols = ['file_name', 'file_size', 'date_processed']
processed_files = util.get_processed_files(db_name, tb_name, tb_cols)
```
其中,'localhost'是数据库的主机地址,'root'是数据库的用户名,'password'是数据库的密码,'mydatabase'是数据库的名称,'mytable'是表名,['file_name', 'file_size', 'date_processed']是需要查询的表字段名称列表。函数返回查询结果,即已处理的文件列表。
相关问题
def get_processed_files(util: MySQLUtil, db_name, tb_name, tb_cols):
As an AI language model, I cannot know the full context of your code or the purpose of this function. However, based on the function signature, it seems that this function takes in a MySQLUtil object, a database name, a table name, and a list of table columns as inputs. It may be used to retrieve processed files from a MySQL database.
Here is a possible implementation of this function:
```
def get_processed_files(util: MySQLUtil, db_name, tb_name, tb_cols):
# Connect to the database
conn = util.connect(db_name)
# Select the specified columns from the table
cols_str = ", ".join(tb_cols)
query = f"SELECT {cols_str} FROM {tb_name}"
cursor = conn.cursor()
cursor.execute(query)
# Fetch the results and store them in a list of dictionaries
results = []
for row in cursor.fetchall():
row_dict = {}
for i, col_name in enumerate(tb_cols):
row_dict[col_name] = row[i]
results.append(row_dict)
# Close the cursor and the connection
cursor.close()
conn.close()
return results
```
This implementation uses the MySQLUtil object to connect to the specified database, constructs a SELECT query to retrieve the specified columns from the table, fetches the results and stores them in a list of dictionaries, and finally closes the cursor and the connection before returning the results. Note that this implementation assumes that the table columns are ordered in the same way as the tb_cols list.
const nav2_util::LifecycleNode::WeakPtr & parent
`const nav2_util::LifecycleNode::WeakPtr & parent` 是一个函数参数的声明,它表示一个常量引用,指向类型为 `nav2_util::LifecycleNode::WeakPtr` 的对象。
在这个声明中,`const` 关键字表示该引用是常量引用,即不能通过这个引用修改所引用的对象。`nav2_util::LifecycleNode::WeakPtr` 则是一个类型名,表示一个指向 `nav2_util::LifecycleNode` 类的弱引用指针。
通过将这个声明作为函数参数,可以在函数体内使用 `parent` 引用来访问和操作 `nav2_util::LifecycleNode` 类型的弱引用指针对象。请注意,由于它是常量引用,所以不能通过 `parent` 来修改所引用的对象。