abdulmakuya / my-database-sandbox

Home grown repo for database

Resources

Databases has 1.DML.
2.DDL.
3.DQL.

W3 Schools SQL Data Modeler Workbench QueryBrowser Top mysql database tools MongoDB

select * from student where debt between "100,000"
and "750,000";

Initialization

cd C:\xampp\mysql\bin
prompt>mysql -u root -h localhost -p
show databases;
use [database_name];
show tables;
DESCRIBE dbname.tablename;
CTRL+Break

CREATE db.tablename(
col1 INT AUTO_INCREMENT NOT NULL PRIMARY KEY,
col2 VARCHAR(20) NOT NULL,
col3 VARCHAR(20) NOT NULL);

INSERT INTO [tablename]
(firstcolumn,seccolumn,thirdcolumn)
VALUES
('attributeValue','attributeValue','attributeValue');

ALTER TABLE name ADD column_name TYPE     - after/before

ALTER TABLE name DROP column_name 

ALTER TABLE name CHANGE column_name new_name new type

ALTER TABLE employee
ADD CONSTRAINT employee_airline_fk FOREIGN KEY(id) 
REFERENCES airline (id);



SELECT employee.name,employee.age
FROM employee
INNER JOIN airline
ON employee.airline_id=airline.airline_id
WHERE airline.adress='dar';

//this will list all employees by name and age whose airlines are 
//based in dar

Data Definition statement
ALTER 
RENAME
CREATE
DROP

DATA MANIPULATION Statements
INSERT
UPDATE
DELETE
TRUNCATE

SQL AGGREGATE FUNCTIONS

• max()
• min()
• count()
• count(*)
• avg()

SQL Clauses

• Where
• group by
• having
• order by