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title: Connect Streamlit to MySQL | |
slug: /develop/tutorials/databases/mysql | |
# Connect Streamlit to MySQL | |
## Introduction | |
This guide explains how to securely access a **_remote_** MySQL database from Streamlit Community Cloud. It uses [st.connection](/develop/api-reference/connections/st.connection) and Streamlit's [Secrets management](/develop/concepts/connections/secrets-management). The below example code will **only work on Streamlit version >= 1.28**, when `st.connection` was added. | |
## Create a MySQL database | |
<Note> | |
If you already have a database that you want to use, feel free | |
to [skip to the next step](#add-username-and-password-to-your-local-app-secrets). | |
</Note> | |
First, follow [this tutorial](https://dev.mysql.com/doc/mysql-getting-started/en/) to install MySQL and start the MySQL server (note down the username and password!). Once your MySQL server is up and running, connect to it with the `mysql` client and enter the following commands to create a database and a table with some example values: | |
```sql | |
CREATE DATABASE pets; | |
USE pets; | |
CREATE TABLE mytable ( | |
name varchar(80), | |
pet varchar(80) | |
); | |
INSERT INTO mytable VALUES ('Mary', 'dog'), ('John', 'cat'), ('Robert', 'bird'); | |
``` | |
## Add username and password to your local app secrets | |
Your local Streamlit app will read secrets from a file `.streamlit/secrets.toml` in your app's root directory. Learn more about [Streamlit secrets management here](/develop/concepts/connections/secrets-management). Create this file if it doesn't exist yet and add the database name, user, and password of your MySQL server as shown below: | |
```toml | |
# .streamlit/secrets.toml | |
[connections.mysql] | |
dialect = "mysql" | |
host = "localhost" | |
port = 3306 | |
database = "xxx" | |
username = "xxx" | |
password = "xxx" | |
``` | |
<Important> | |
When copying your app secrets to Streamlit Community Cloud, be sure to replace the values of **host**, **port**, **database**, **username**, and **password** with those of your _remote_ MySQL database! | |
Add this file to `.gitignore` and don't commit it to your GitHub repo! | |
</Important> | |
## Copy your app secrets to the cloud | |
As the `secrets.toml` file above is not committed to GitHub, you need to pass its content to your deployed app (on Streamlit Community Cloud) separately. Go to the [app dashboard](https://share.streamlit.io/) and in the app's dropdown menu, click on **Edit Secrets**. Copy the content of `secrets.toml` into the text area. More information is available at [Secrets management](/deploy/streamlit-community-cloud/deploy-your-app/secrets-management). | |
 | |
## Add dependencies to your requirements file | |
Add the [mysqlclient](https://github.com/PyMySQL/mysqlclient) and [SQLAlchemy](https://github.com/sqlalchemy/sqlalchemy) packages to your `requirements.txt` file, preferably pinning its version (replace `x.x.x` with the version you want installed): | |
```bash | |
# requirements.txt | |
mysqlclient==x.x.x | |
SQLAlchemy==x.x.x | |
``` | |
## Write your Streamlit app | |
Copy the code below to your Streamlit app and run it. Make sure to adapt `query` to use the name of your table. | |
```python | |
# streamlit_app.py | |
import streamlit as st | |
# Initialize connection. | |
conn = st.connection('mysql', type='sql') | |
# Perform query. | |
df = conn.query('SELECT * from mytable;', ttl=600) | |
# Print results. | |
for row in df.itertuples(): | |
st.write(f"{row.name} has a :{row.pet}:") | |
``` | |
See `st.connection` above? This handles secrets retrieval, setup, query caching and retries. By default, `query()` results are cached without expiring. In this case, we set `ttl=600` to ensure the query result is cached for no longer than 10 minutes. You can also set `ttl=0` to disable caching. Learn more in [Caching](/develop/concepts/architecture/caching). | |
If everything worked out (and you used the example table we created above), your app should look like this: | |
 | |