SQl Para Dummies

Conectarse a mysql

CODE:

1.

mysql -h localhost -u root -p pruebas

albertjh@portatil:~$ mysql -u root -p

Enter password:

Welcome to the MySQL monitor. Commands end with ; or \g.

Your MySQL connection id is 7

Server version: 5.0.51a-3ubuntu5 (Ubuntu)

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql>

Crear una base de datos

SQL:

1.

CREATE DATABASE pruebas;

Usar una base de datos

PLAIN TEXT

SQL:

1.

USE pruebas;

mysql> use prueba;

Reading table information for completion of table and column names

You can turn off this feature to get a quicker startup with -A

Ver estructura de una tabla de datos

PLAIN TEXT

SQL:

1.

DESCRIBE Alumnos ;

mysql> describe alumnos;

+-----------+-------------+------+-----+---------+-------+

| Field | Type | Null | Key | Default | Extra |

+-----------+-------------+------+-----+---------+-------+

| Id | int(11) | YES | | 0 | |

| nombre | varchar(10) | YES | | NULL | |

| apellidos | varchar(30) | YES | | NULL | |

| tlfn | int(10) | YES | | NULL | |

+-----------+-------------+------+-----+---------+-------+

4 rows in set (0.00 sec)

mysql>

Ver tablas de datos

SQL:

1.

SHOW TABLES;

mysql> show tables;

+------------------+

| Tables_in_prueba |

+------------------+

| Notas |

| alumnos |

| mascotas |

+------------------+

3 rows in set (0.00 sec)

Borrar tabla de datos

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SQL:

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DROP Notas;

Crear una tabla de datos

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SQL:

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CREATE TABLE Alumnos(

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id INT NOT NULL,

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nombre VARCHAR (10) NOT NULL,

4.

apellido VARCHAR (10) NOT NULL,

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telefono LONG,

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CONSTRAINT alumnosPk1 PRIMARY KEY (id)

7.

);

8.

9.

CREATE TABLE Notas(

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id INT NOT NULL,

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modulo VARCHAR (10) NOT NULL,

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parcial INT NOT NULL,

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nota INT NOT NULL CHECK (VALUE BETWEEN 1 AND 10),

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CONSTRAINT notasPk1 PRIMARY KEY (id, modulo),

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CONSTRAINT notasfk1 FOREIGN KEY (id) REFERENCES Alumnos(id)

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);

Insertar datos en una tabla de datos

PLAIN TEXT

SQL:

1.

INSERT INTO Alumnos VALUES(’1′,‘juan’,‘garcia’,’949494949′);

2.

INSERT INTO Alumnos VALUES(’2′,‘maria’,‘alvarez’,”);

3.

INSERT INTO Alumnos VALUES(’3′,‘carlos’,‘perez’,’6458544′);

4.

INSERT INTO Alumnos VALUES(’4′,‘alberto’,‘jimenez’,”);

5.

INSERT INTO Alumnos VALUES(’5′,‘vanesa’,‘galera’,’912552522′);

6.

INSERT INTO Alumnos VALUES(’6′,‘sergio’,‘molina’,’5464465656′);

...