SQL Cheat Sheet

SQL Basics:

1. Create Database:

CREATE DATABASE database_name;

2. Use Database:

USE database_name;

3. Create Table:

CREATE TABLE table_name (
    column1 datatype,
    column2 datatype,
    ...
);
    

4. Insert Data:

INSERT INTO table_name (column1, column2, ...) VALUES (value1, value2, ...);

Example:

INSERT INTO students (id, name, age) VALUES (1, 'John Doe', 20);

5. Select Data:

SELECT column1, column2, ... FROM table_name WHERE condition;

Example:

SELECT * FROM employees WHERE department = 'IT';

6. Update Data:

UPDATE table_name SET column1 = value1, column2 = value2, ... WHERE condition;

Example:

UPDATE products SET price = 25.99 WHERE id = 101;

7. Delete Data:

DELETE FROM table_name WHERE condition;

Example:

DELETE FROM customers WHERE last_purchase_date < '2022-01-01';

8. Joins:

Inner Join:

SELECT columns FROM table1 INNER JOIN table2 ON table1.column = table2.column;

Left Join:

SELECT columns FROM table1 LEFT JOIN table2 ON table1.column = table2.column;

Python - SQL Connection:

1. Install Required Package aka Installation command:

pip install mysql-connector-python

2. Connect to Database:

import mysql.connector

mydb = mysql.connector.connect(
    host="your_host",
    user="your_username",
    password="your_password",
    database="your_database"
)
    

3. Create a Cursor:

mycursor = mydb.cursor()

4. Execute SQL Query:

sql_query = "SELECT * FROM your_table;"
mycursor.execute(sql_query)

result = mycursor.fetchall()
for row in result:
    print(row)
    

5. Insert Data:

sql_insert = "INSERT INTO your_table (column1, column2, ...) VALUES (%s, %s, ...)"
values = (value1, value2, ...)
mycursor.execute(sql_insert, values)

mydb.commit()