Learning SQL for beginners (0)Ajenda

If you do not know about computer system development and want to learn SQL, this post may be helpful for you.
This post is an agenda, so in other post, more detail information will be written.

1. Prepare

At first, you can visit a site bellow: http://www.wampserver.com/

After that, you can download and install to your computer. By the way, although you learn about SQL, why WAMP is required? Actually only MySQL is enough. but somehow the file size of WAMP is smaller than My SQL. So you can download and install it quickly.

2. Setting

After WAMP has been installed, open bellow: http://localhost/phpmyadmin

Database -> Create database -> ( name ) -> Create

3. Practice

Next, open "mySQL consle"

password :(null)
use (name)
  1. create
CREATE TABLE TMEMBER01(
		NID			INT(3),
		CNAME		VARCHAR(30),
		CADDRESS	VARCHAR(40),
		DBIRTHDATE	DATE,
		CNOTICE		VARCHAR(20)
);
  1. drop
drop table tmember01;
  1. select (show)
SELECT
		*
FROM
		TMEMBER01;
-- This is same as upward
SELECT
		NID, CNAME, CADDRESS, DBIRTHDATE, CNOTICE
FROM
		TMEMBER01;
  1. insert
insert into TMEMBER01(
		NID, CNAME, CADDRESS, DBIRTHDATE, CNOTICE
)
values(
		101, 'Yokota Kaoru', 'Cau Giay', '1978/05/15', 'employee'
);
---
insert into TMEMBER01(
		NID, CNAME, CADDRESS, DBIRTHDATE, CNOTICE
)
values(
		102, 'Suzuki Takashi', 'Trang Thay Tong', '1981/09/01', 'employee'
);
---
insert into TMEMBER01(
		NID, CNAME, CADDRESS, DBIRTHDATE, CNOTICE
)
values(
		103, 'Yamada Norio', 'Kim Ma', '1989/12/03', 'intern'
);
  1. clone
-- with records
CREATE TABLE TMEMBER02
SELECT * FROM TMEMBER01;
-- without records, that is, only table def
CREATE TABLE TMEMBER11
SELECT * FROM TMEMBER01
where 1=0;
  1. update
UPDATE
		TMEMBER01
SET
		CADDRESS ='Dao Cat Ba'
where
		NID=103;
  1. delete
DELETE FROM
		TMEMBER01
WHERE
		NID=102;
  1. all delete
TRUNCATE TABLE TMEMBER01;

This is same as "DELETE FROM TMEMBER01;". But it is faster than delete command, and better memory usage.

4. End of Practice

exit

5. Appendix

if you are an Oracle Database Programmer, you can find some difference between Oracle and MySQL.

How different are data types?

Oracle MySQL
number int
varchar2 varchar
date datetime

[note]In fact, we can use "date" in MySQL. But it is quite different with Oracle. In MySQL, "date" can have only "YYYY/MM/DD" although Oracle can have "YYYY/MM/DD hh:mm:ss". When we want to have "YYYY/MM/DD hh:mm:ss" in MySQL, we have to use "datetime" type.


この記事は英語版です。日本語版は以下リンクをどうぞ。
https://viblo.asia/Kaoru/posts/YAQrMJw7G40E


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