Com uma prova de BD amanhã resolvi estudar aqui ;-)
"With a future proof BD decided to study here"
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Some of the classes command are: data selection, manipulation and definition among others, more important today is the one for my study.
- Manipulation : insert, update, delete.
- Definition : create,alter,drop,rename ...
- Selection : select.
how to create a database?
>mysql create database blog;
to use your DB !
mysql> use blog;
creating a table?
mysql> create table pessoa(
-> id_p int(10) primary key auto_increment,
-> nome varchar(30) not null);
mysql> insert into pessoa (nome) values ('andre');
mysql> insert into pessoa (nome) values ('will');
mysql> insert into pessoa (nome) values ('keila');
mysql> insert into pessoa (nome) values ('safira');
mysql> insert into pessoa (nome) values ('glenda');
>mysql select * from pessoa;
+------+--------+
| id_p | nome |
+------+--------+
| 1 | andre |
| 2 | will |
| 3 | keila |
| 4 | safira |
| 5 | glenda |
+------+--------+
how to create table with the relationship between two tables,recuparar your values?
(1 'pessoa' may have "N" 'contato')
mysql> create table contato(
-> id_c int(10) primary key auto_increment,
-> numero int (10) not null,
-> id_p int(10) not null,
-> index id_p(id_p),
-> foreign key (id_p) references pessoa(id_p));
mysql> insert into contato (numero,id_p) values(88225190,1);
mysql> insert into contato (numero,id_p) values(23123434,1);
mysql> insert into contato (numero,id_p) values(98453434,2);
mysql> insert into contato (numero,id_p) values(56353664,3);
mysql> insert into contato (numero,id_p) values(38793664,4);
mysql> insert into contato (numero,id_p) values(66793664,5);
mysql> select * from pessoa inner join contato on pessoa.id_p = contato.id_p;
+------+--------+------+----------+------+
| id_p | nome | id_c | numero | id_p |
+------+--------+------+----------+------+
| 1 | andre | 3 | 88225190 | 1 |
| 1 | andre | 4 | 23123434 | 1 |
| 2 | will | 5 | 98453434 | 2 |
| 3 | keila | 6 | 56353664 | 3 |
| 4 | safira | 7 | 38793664 | 4 |
| 5 | glenda | 8 | 77793664 | 5 |
| 5 | glenda | 9 | 66793664 | 5 |
+------+--------+------+----------+------+--
some kind of selection !
mysql> select * from pessoa where nome like 'a%';
+------+-------+
| id_p | nome |
+------+-------+
| 1 | andre |
+------+-------+
mysql> select * from pessoa where nome like 'a%' or nome like 'g%';
+------+--------+
| id_p | nome |
+------+--------+
| 1 | andre |
| 5 | glenda |
+------+--------+
mysql> select * from pessoa where nome regexp '^[A-H]';
+------+--------+
| id_p | nome |
+------+--------+
| 1 | andre |
| 5 | glenda |
+------+--------+
mysql> Select * from pessoa limit 2,2;
+------+--------+
| id_p | nome |
+------+--------+
| 3 | keila |
| 4 | safira |
+------+--------+
modifying table !
no implemented by me!
sintax
sintax
*ALTER TABLE pessoa DROP column;
*ALTER TABLE pessoa CHANGE nome name char(30) not null;
*ALTER TABLE pessoa CHANGE nome name char(30) not null;
last
mysql> desc pessoa;
+-------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+----------------+
| id_p | int(10) | NO | PRI | NULL | auto_increment |
| nome | varchar(30) | NO | | NULL | |
+-------+-------------+------+-----+---------+----------------+
mysql> alter table pessoa add data date;
Query OK, 5 rows affected
mysql> desc pessoa;
+-------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+----------------+
| id_p | int(10) |NO | PRI | NULL | auto_increment |
| nome| varchar(30) | NO | | NULL | |
| data | date | YES | | NULL | |
+-------+-------------+------+-----+---------+----------------+
mysql> select * from pessoa;
+------+--------+------+
| id_p | nome | data |
+------+--------+------+
| 1 | andre | NULL |
| 2 | will | NULL |
| 3 | keila | NULL |
| 4 | safira | NULL |
| 5 | glenda | NULL |
+------+--------+------+
mysql> show tables;
+----------------+
| Tables_in_blog |
+----------------+
| contato |
| pessoa |
+----------------+
mysql> desc contato;
+--------+---------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+--------+---------+------+-----+---------+----------------+
| id_c | int(10) | NO | PRI | NULL | auto_increment |
| numero | int(10) | NO| | NULL | |
| id_p | int(10) | NO | MUL | NULL | |
+--------+---------+------+-----+---------+----------------+
mysql> desc pessoa;
+-------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+----------------+
| id_p | int(10) | NO | PRI | NULL | auto_increment |
| nome | varchar(30) | NO| | NULL | |
| data | date | YES | | NULL | |
+-------+-------------+------+-----+---------+----------------+
union
requires tables with the same fields.
mysql> desc pessoa;
+---------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+---------+-------------+------+-----+---------+----------------+
| id_p | int(10) | NO | PRI | NULL | auto_increment |
| nome | varchar(30) | NO | | NULL | |
| caddate | date | NO | | NULL | |
| idade | int(3) | YES | | NULL | |
+---------+-------------+------+-----+---------+----------------+
mysql> desc person;
+---------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+---------+-------------+------+-----+---------+----------------+
| id_p | int(10) | NO | PRI | NULL | auto_increment |
| nome | varchar(30) | NO | | NULL | |
| caddate | date | NO | | NULL | |
| idade | int(3) | YES | | NULL | |
+---------+-------------+------+-----+---------+----------------+
mysql> insert into person (nome,caddate,idade) values('andre',current_date,21);
mysql> insert into person (nome,caddate,idade) values('marcelo',current_date,17);
mysql> insert into pessoa (nome,caddate,idade) values('cleo',current_date,48);
mysql> insert into pessoa (nome,caddate,idade) values('francisco',current_date,49);
mysql> select * from person;
+------+---------+------------+-------+
| id_p | nome | caddate | idade |
+------+---------+------------+-------+
| 1 | andre | 2011-09-29 | 21 |
| 2 | marcelo | 2011-09-29 | 17 |
+------+---------+------------+-------+
mysql> select * from pessoa;
+------+-----------+------------+-------+
| id_p | nome | caddate | idade |
+------+-----------+------------+-------+
| 1 | cleo | 2011-09-29 | 48 |
| 2 | francisco | 2011-09-29 | 49 |
+------+-----------+------------+-------+
mysql> select * from person union select * from pessoa;
+------+-----------+------------+-------+
| id_p | nome | caddate | idade |
+------+-----------+------------+-------+
| 1 | andre | 2011-09-29 | 21 |
| 2 | marcelo | 2011-09-29 | 17 |
| 1 | cleo | 2011-09-29 | 48 |
| 2 | francisco | 2011-09-29 | 49 |
+------+-----------+------------+-------+
some kind of selection !
mysql> select * from pessoa where caddate >= 2011-09-29 ;
+------+-----------+------------+-------+
| id_p | nome | caddate | idade |
+------+-----------+------------+-------+
| 1 | cleo | 2011-09-29 | 48 |
| 2 | francisco | 2011-09-29 | 49 |
+------+-----------+------------+-------+
mysql> select * from pessoa where month(caddate) = 09;
+------+-----------+------------+-------+
| id_p | nome | caddate | idade |
+------+-----------+------------+-------+
| 1 | cleo | 2011-09-29 | 48 |
| 2 | francisco | 2011-09-29 | 49 |
+------+-----------+------------+-------+
mysql> select * from pessoa where day(caddate) = 29;
+------+-----------+------------+-------+
| id_p | nome | caddate | idade |
+------+-----------+------------+-------+
| 1 | cleo | 2011-09-29 | 48 |
| 2 | francisco | 2011-09-29 | 49 |
+------+-----------+------------+-------+
mysql> select * from pessoa where year(caddate) = 2011;
+------+-----------+------------+-------+
| id_p | nome | caddate | idade |
+------+-----------+------------+-------+
| 1 | cleo | 2011-09-29 | 48 |
| 2 | francisco | 2011-09-29 | 49 |
+------+-----------+------------+-------+
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