💡
SQL cheatsheet
SQL queries order
In a non-image format, the order is:
- FROM/JOIN and all the ON conditions
- WHERE
- GROUP BY
- HAVING
- SELECT (including window functions)
- ORDER BY
- LIMIT
Create Database
sql
CREATE DATABASE nameofdatabase;example:CREATE DATABASE school;
Create Table
sql
CREATE TABLE tablename(attribute datatype);example:CREATE TABLE student(rollno INT AUTO_INCREMENT,first_name VARCHAR(100),last_name VARCHAR(100),class INT,DOB VARCHAR(50), PRIMARY KEY(rollno);
Insert Row/Record
sql
INSERT INTO tablename(attribute) values('value');example:/* inserting single value */query:INSERT INTO student(first_name,last_name,class,DOB)values('John','Doe',9,'21 oct 1999');result:+--------+------------+-----------+-------+-------------+| rollno | first_name | last_name | class | DOB |+--------+------------+-----------+-------+-------------+| 1 | John | Doe | 9 | 21 oct 1999 |+--------+------------+-----------+-------+-------------+/* inserting multiple values */query:INSERT INTO student(first_name,last_name,class,DOB)values('Jim','Shaw',10,'7 dec 2000'),('Brad','Traversy',10,'28 apr 2010'),('Chris','Walker',5,'4 jan 2014');result:+--------+------------+-----------+-------+-------------+| rollno | first_name | last_name | class | DOB |+--------+------------+-----------+-------+-------------+| 1 | John | Doe | 9 | 21 oct 1999 || 2 | Jim | Shaw | 10 | 7 dec 2000 || 3 | Brad | Traversy | 10 | 28 apr 2010 || 4 | Chris | Walker | 5 | 4 jan 2014 |+--------+------------+-----------+-------+-------------+
Resources
- Online SQL Teaching
- SQL Join Types Explained Visually
- knex.js: A batteries-included, multi-dialect (PostgreSQL, MySQL, CockroachDB, MSSQL, SQLite3, Oracle (including Oracle Wallet Authentication)) query builder for Node.js
