In the field of data analysis and processing, the use of Python in conjunction with SQL databases has become a standard practice.
Python provides a variety of libraries and tools that make it easy to connect to and manipulate SQL databases.
This article will start from scratch and lead you step by step to master how to connect Python to SQL databases.
Install the database driver.
Before you can use Python to connect to a SQL database, you need to install the corresponding database driver. Different databases have different drivers, and the following is an example of MySQL and SQLITE.
MySQL driver: Python uses the mysql-connector-python library to connect to a MySQL database. You can use the pip command to install:
pip install mysql-connector-python
SQLite Driver: SQLite is a lightweight database that comes with the SQLite driver in the Python standard library, so no additional installation is required.
Establish a database connection.
Once the driver is installed, you can use Python to establish a connection to the SQL database. The following shows how to connect to MySQL and SQLite, respectively.
Connect to the MySQL database
import mysql.connector to create a connection. connection = mysql.connector.connect(host="localhost", database host address user="your_username", database username password="your_password", database password database="your_database"databasename) cursor = connectioncursor() creates a cursor object
Connect to the sqlite database:
import sqlite3 to create a connection = sqlite3connect('your_database.db') database file path to create cursor object cursor = connectioncursor()
Execute the query. Once the connection is established, you can use the cursor object to execute SQL queries. Here are some basic query operations.
Execute the query statement.
cursor.execute("select * from your_table")
Get the query results.
results = cursor.fetchall()
Traverse the query results.
for row in results:(tab)print(row)
Database editing.
Insert data: cursorexecute("insert into your_table (column1, column2) values (?", ("value1", "value2"))connection.commit() commit...
Update the data. cursor.execute("update your_table set column1 = ? where column2 = ?", ("new_value", "condition_value"))connection.commit() commit...
Deletion of data. cursor.execute("delete from your_table where column1 = ?", ("value_to_delete",))connection.commit() commit...
Close the connection. When you're done with the database, remember to close the cursor and connections to free up resources.
Close cursorclose() closes the connectionclose()
Summary. Through the introduction of this article, you should have mastered how to use Python to connect to a SQL database and perform basic adding, deleting, modifying and querying operations.
With practice and practice, you will be able to become more proficient in using Python to interact with SQL databases.