-- aprender a criar uma tabela
-- crie uma tabela chamada studants, com um id, name, gender
CREATE TABLE students (
  id INT AUTO_INCREMENT PRIMARY KEY,
  name TEXT NOT NULL,
  gender TEXT NOT NULL
);

-- vamos inserir alguns valores na tabela
INSERT INTO students (name, gender) VALUES ('Ryan', 'M');
INSERT INTO students (name, gender) VALUES ('Joanna', 'F');

-- vamos consultar apenas determinados valores
-- SELECT * FROM students WHERE gender = 'F';

-- vamos inserir alguns valores na tabela
INSERT INTO students (name, gender) VALUES ('Leonildas', 'F');
INSERT INTO students (name, gender) VALUES ('Janethy', 'F');

-- vamos fazer uma consulta na tabela por todos valores que temos dentro da tabela studants
SELECT * FROM students;

-- renomear a tabela studants para Estudantes
RENAME TABLE students to estudantes;

-- alterar a tabela, inserindo mais uma coluna turma
ALTER TABLE estudantes ADD turma TEXT NOT NULL;

-- vamos fazer uma consulta na tabela por todos valores que temos dentro da tabela studants
SELECT * FROM estudantes;

-- alterar a tabela, inserindo mais uma coluna curso
ALTER TABLE estudantes ADD curso TEXT NOT NULL;

-- vamos fazer uma consulta na tabela por todos valores que temos dentro da tabela studants
SELECT * FROM estudantes;

-- vamos inserir alguns valores na tabela
INSERT INTO estudantes (name, gender, turma, curso) 
VALUES ('João Silva', 'M', '501', 'Informática'), 
('Mario Santos', 'M', '501', 'Administração'),
('Erick', 'M', '501', 'Informática');

-- vamos fazer uma consulta na tabela por todos valores que temos dentro da tabela studants
SELECT * FROM estudantes;

-- renomear a coluna name para nome
ALTER TABLE estudantes CHANGE COLUMN name nome VARCHAR(50);
ALTER TABLE estudantes CHANGE COLUMN gender genero VARCHAR(50);

-- vamos fazer uma consulta na tabela por todos valores que temos dentro da tabela studants
SELECT * FROM estudantes;

UPDATE Estudantes SET nome = 'Lukas' WHERE nome = 'Ryan';
UPDATE Estudantes SET curso = 'Comércio Exterior' WHERE id = 1;
UPDATE Estudantes SET curso = 'Informática' WHERE id = 2;
UPDATE Estudantes SET curso = 'Recursos Humanos' WHERE id = 3;
UPDATE Estudantes SET curso = 'Banco de dados' WHERE id = 4;
UPDATE Estudantes SET turma = '501' WHERE turma IS NULL OR turma = '';

-- vamos fazer uma consulta na tabela por todos valores que temos dentro da tabela studants
SELECT * FROM estudantes;

-- vamos consultar apenas determinados valores (por curso)
SELECT * FROM estudantes WHERE curso = 'Informática';

MySQL online editor

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About MySQL

MySQL is a open-source, free and very popular relational database management system which is developed, distributed and supported by Oracle corporation.

Key Features:

  • Open-source relational database management systems.
  • Reliable, very fast and easy to use database server.
  • Works on client-server model.
  • Highly Secure and Scalable
  • High Performance
  • High productivity as it uses stored procedures, triggers, views to write a highly productive code.
  • Supports large databases efficiently.
  • Supports many operating systems like Linux*,CentOS*, Solaris*,Ubuntu*,Windows*, MacOS*,FreeBSD* and others.

Syntax help

Commands

1. CREATE

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

Example

CREATE TABLE EMPLOYEE (
  empId INTEGER PRIMARY KEY,
  name TEXT NOT NULL,
  dept TEXT NOT NULL
);

2. ALTER

ALTER TABLE Table_name ADD column_name datatype;

Example

INSERT INTO EMPLOYEE VALUES (0001, 'Dave', 'Sales');

3. TRUNCATE

TRUNCATE table table_name;

4. DROP

DROP TABLE table_name;

5. RENAME

RENAME TABLE table_name1 to new_table_name1;

6. COMMENT

Single-Line Comments:

 --Line1;

Multi-Line comments:

   /* Line1,
   Line2 */

DML Commands

1. INSERT

INSERT INTO table_name (column1, column2, column3, ...) VALUES (value1, value2, value3, ...);

Note: Column names are optional.

Example

INSERT INTO EMPLOYEE VALUES (0001, 'Ava', 'Sales');

2. SELECT

SELECT column1, column2, ...
FROM table_name
[where condition];

Example

SELECT * FROM EMPLOYEE where dept ='sales';

3. UPDATE

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

Example

UPDATE EMPLOYEE SET dept = 'Sales' WHERE empId='0001';

4. DELETE

DELETE FROM table_name where condition;

Example

DELETE from EMPLOYEE where empId='0001';

Indexes

1. CREATE INDEX

  CREATE INDEX index_name on table_name(column_name);
  • To Create Unique index:
  CREATE UNIQUE INDEX index_name on table_name(column_name);

2. DROP INDEX

DROP INDEX index_name ON table_name;

Views

1. Create a View

Creating a View:
CREATE VIEW View_name AS 
Query;

2. How to call view

SELECT * FROM View_name;

3. Altering a View

ALTER View View_name AS 
Query;

4. Deleting a View

DROP VIEW View_name;

Triggers

1. Create a Trigger

CREATE TRIGGER trigger_name trigger_time trigger_event
    ON tbl_name FOR EACH ROW [trigger_order] trigger_body
/* where
trigger_time: { BEFORE | AFTER }
trigger_event: { INSERT | UPDATE | DELETE }
trigger_order: { FOLLOWS | PRECEDES } */

2. Drop a Trigger

DROP TRIGGER [IF EXISTS] trigger_name;

Stored Procedures

1. Create a Stored Procedure

CREATE PROCEDURE sp_name(p1 datatype)
BEGIN
/*Stored procedure code*/
END;

2. How to call Stored procedure

CALL sp_name;

3. How to delete stored procedure

DROP PROCEDURE sp_name;

Joins

1. INNER JOIN

SELECT * FROM TABLE1 INNER JOIN TABLE2 where condition;

2. LEFT JOIN

SELECT * FROM TABLE1 LEFT JOIN TABLE2 ON condition;

3. RIGHT JOIN

SELECT * FROM TABLE1 RIGHT JOIN TABLE2 ON condition;

4. CROSS JOIN

SELECT select_list from TABLE1 CROSS JOIN TABLE2;