Database

Database Management

Show databases SHOW DATABASES;
Create a database CREATE DATABASE database_name;
Use a database USE database_name;
Drop a database DROP DATABASE database_name;

Table Management

Show tables SHOW TABLES;
Create a table CREATE TABLE table_name (column1 datatype PRIMARY KEY, column2 datatype, column3 datatype );
Describe table structure DESCRIBE table_name;
Drop a table DROP TABLE table_name;
Alter a table (add column) ALTER TABLE table_name ADD column_name datatype;
Alter a table (drop column) ALTER TABLE table_name DROP COLUMN column_name;

Data Manipulation (CRUD Operations)

Insert Data

Insert into table INSERT INTO table_name (column1, column2) VALUES ('value1', 'value2');

Read Data

Select all records SELECT * FROM table_name;
Select specific columns SELECT column1, column2 FROM table_name;
Filter data (WHERE clause) SELECT * FROM table_name WHERE column1 = 'value';

Update Data

Update records UPDATE table_name SET column1 = 'new_value' WHERE column2 = 'condition';

Delete Data

Delete specific records DELETE FROM table_name WHERE column1 = 'value';
Delete all records DELETE FROM table_name;

Query Modifiers

Sorting (ORDER BY) SELECT * FROM table_name ORDER BY column_name ASC; -- ASC (Ascending) | DESC (Descending)
Limit results SELECT * FROM table_name LIMIT 10;
Count rows SELECT COUNT(*) FROM table_name;

Joins

Inner Join SELECT a.column, b.column FROM tableA a INNER JOIN tableB b ON a.common_column = b.common_column;
Left Join SELECT a.column, b.column FROM tableA a LEFT JOIN tableB b ON a.common_column = b.common_column;
Right Join SELECT a.column, b.column FROM tableA a RIGHT JOIN tableB b ON a.common_column = b.common_column;
Use the link below to learn more about joins

https://www.atlassian.com/data/sql/sql-join-types-explained-visually

Aggregation Functions

Sum SELECT SUM(column_name) FROM table_name;
Average SELECT AVG(column_name) FROM table_name;
Maximum / Minimum SELECT MAX(column_name) FROM table_name; SELECT MIN(column_name) FROM table_name;
Group By SELECT column_name, COUNT(*) FROM table_name GROUP BY column_name;

Free learning resources

https://www.w3schools.com/sql/