mysql_2025

Just some fun. (And going for SQL Gold and Certs on Hacker Rank.)

Setup and Use

Docker Compose:

docker compose up

Connection settings:

Host:       localhost:3306
User:       example
Password:   example
Database:   example

Scripts

Execute SQL through the Docker Shell:

# Exec in and login
mysql --user=example --password=example lab

# Execute command
mysql> SELECT * FROM jsonexample;

mysql> exit

Execute supplied scripts:

mysql --user=example --password=example lab

mysql> source ./scripts/restart.sql

mysql> source ./scripts/HackerRank-Occupations.sql
mysql> source ./scripts/HackerRank-TypeOfTriangle.sql
mysql> source ./scripts/HackerRank-TopEarners.sql
mysql> source ./scripts/HackerRank-ThePADS.sql
mysql> source ./scripts/HackerRank-NewCompanies.sql
mysql> source ./scripts/HackerRank-WeatherStation8.sql
mysql> source ./scripts/HackerRank-WeatherStation18.sql
mysql> source ./scripts/HackerRank-WeatherStation19.sql
mysql> source ./scripts/HackerRank-WeatherStation20.sql
mysql> source ./scripts/HackerRank-Interviews.sql
mysql> source ./scripts/HackerRank-DrawTheTriangle1.sql
mysql> source ./scripts/HackerRank-DrawTheTriangle2.sql
mysql> source ./scripts/HackerRank-SymmetricPairs.sql

Gotcha's and Review Topics

1. MySQL 8.0 requires passing number of chars in the VARCHAR type.
2. MySQL 8.0 BEGIN and END requires DELIMITERS.
3. mysql> source requires ./ for file paths.
4. Uses LIMIT prepended not TOP (per MSSQL).
5. WITH cannot be used with MySQL prior to 8.0 (sadly, HackerRank uses MySQL versions <8.0 and WITH queries will error out on the platform).

Resources and Links

1. https://dev.mysql.com/doc/refman/8.4/en/char.html
2. https://stackoverflow.com/questions/8940230/how-to-run-sql-script-in-mysql