How to query database data with Python?

6 months ago

2 minutes

In Python, querying database data is typically done using SQL statements. This involves first connecting to the database, constructing the SQL query statement, and then executing the query.

Here is a simple example using Python’s sqlite3 module to query data from a SQLite database.

import sqlite3

# 连接到数据库
conn = sqlite3.connect('example.db')
cur = conn.cursor()

# 执行查询操作
cur.execute("SELECT * FROM table_name")

# 获取查询结果
rows = cur.fetchall()

# 打印查询结果
for row in rows:
    print(row)

# 关闭数据库连接
conn.close()

In the code above, the SQLite database is first connected using the sqlite3.connect() function and a cursor object is created. Subsequently, the SQL query is executed using the cursor.execute() method, and the results are retrieved using cursor.fetchall(). Finally, the results are iterated through and printed out.

It is necessary to adjust the SQL query statement based on the specific situation to retrieve specific data. If using a different database, the corresponding database library can be used to connect and query data.