Difference between revisions of "Data type"

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** (1) HEX: CHAR(64) Using [http://php.net/manual/en/function.hash-file.php PHP: hash_file()], MySQL [https://dev.mysql.com/doc/refman/5.6/en/encryption-functions.html#function_sha2 SHA2(str, hash_length)]
 
** (1) HEX: CHAR(64) Using [http://php.net/manual/en/function.hash-file.php PHP: hash_file()], MySQL [https://dev.mysql.com/doc/refman/5.6/en/encryption-functions.html#function_sha2 SHA2(str, hash_length)]
 
** (2) Binary: BINARY(32) Using [http://php.net/manual/en/function.hex2bin.php hex2bin()] in PHP e.g. {{kbd | key=<nowiki>echo hex2bin(hash_file('sha256', $file_path));</nowiki>}}, In MySQL e.g. {{kbd | key=<nowiki>SELECT UNHEX(SHA2('The quick brown fox jumped over the lazy dog.', 256))</nowiki>}}
 
** (2) Binary: BINARY(32) Using [http://php.net/manual/en/function.hex2bin.php hex2bin()] in PHP e.g. {{kbd | key=<nowiki>echo hex2bin(hash_file('sha256', $file_path));</nowiki>}}, In MySQL e.g. {{kbd | key=<nowiki>SELECT UNHEX(SHA2('The quick brown fox jumped over the lazy dog.', 256))</nowiki>}}
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 +
==== Retrieve the hash value from string or file content ====
  
 
PHP:
 
PHP:
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SELECT SHA2('The quick brown fox jumped over the lazy dog.', 256)
 
SELECT SHA2('The quick brown fox jumped over the lazy dog.', 256)
 
</pre>
 
</pre>
 +
 +
==== Retrieve the hash value from binary value ====
 +
* PHP: [http://php.net/manual/en/function.bin2hex.php bin2hex()] e.g. {{kbd | key=<nowiki>echo bin2hex(hex2bin(hash('sha256', 'The quick brown fox jumped over the lazy dog.')));</nowiki>}}
 +
* MySQL: [https://dev.mysql.com/doc/refman/8.0/en/hexadecimal-literals.html Hexadecimal Literals] e.g. {{kbd | key=<nowiki>SELECT HEX(UNHEX(SHA2('The quick brown fox jumped over the lazy dog.', 256)));</nowiki>}}<ref>[https://stackoverflow.com/questions/14608413/storing-a-binary-sha1-hash-into-a-mysql-binary20-column insert - Storing a binary SHA1 hash into a mySQL BINARY(20) column - Stack Overflow]</ref>
  
 
=== membership ===
 
=== membership ===

Revision as of 12:08, 5 June 2018

資料表欄位設計時,針對不同資料類型,建議的資料型態(data type)

examples of data and suggested datatype

birth year

  • data type: int
  • ex: Range from 1905 ~ 2013 (108 yeas old) from the Sing-up form from outlook.com [Last visited: 2013-02-04]
  • range/limit: 122 yeas old[1]

file name

file name for Win Os windows.png FTFS ; Linux Os linux.png ex3 and ex4 file system types[2].

  • varchar(255) [3][4] Icon_exclaim.gif If the files hosted by Windows server, you should also take the limit of PATH length into account besides the limit of filename length.

IP

IP(v4)

  • varchar(15)
  • ex: 255.255.255.255 [5]

range/limit

  • IP range - Classless inter-domain routing (CIDR)[6]
    • 12 or 24 bytes (IPv4 and IPv6 networks)[7]
    • ex: 69.208.0.0/32

IPv6: 128位元長度,以16位元為一組,每組以冒號":"隔開,可以分為8組,每組以4位元十六進制方式表示

    • data type:
    • ex: 2001:0db8:85a3:08d3:1319:8a2e:0370:7344

網址

Chinese name

  • 最長姓名有13個字 [10][11]
  • 參考別人: LINE姓名欄位長度限制: 15字(15個中文字或15英文字母)

unix timestamp

  • bigint(10) ;
  • ex: 1328664539
  • range/limit:

duration 時長

  • data type: TIMETIME values may range from '-838:59:59' to '838:59:59'」[12]
  • format: 小時:分鐘:秒 hh:mm:ss
  • 參考別人: Google form 問卷題目選項的小時 0~72 ; 分鐘: 00~59: 秒: 00~59

學校代碼

School ID defined by MOE at Taiwan / 學校代碼[13]

  • integer: 4(university) ~ 6
  • ex: 0001(國立政治大學)、373607(臺北市立華江國小)。前面可能有零。
  • range/limit:

經緯度 (經度,緯度)

  • DECIMAL(18,12)[14] or FLOAT( 10, 6 )[15] or VARCHAR( 30 )
  • ex: 37.401724,-122.114646
  • range/limit:

價錢/金額

  • DECIMAL(10,2)[16][17]
  • ex:
  • range/limit: 0.00 ~ 99999999.99

台灣縣市欄位值

台灣縣市欄位值 下拉式選單[18]

$city = array("基隆市", "台北市", "新北市", "桃園縣", "新竹市", "新竹縣", "苗栗縣", "台中市", 
        "彰化縣", "南投縣", "雲林縣", "嘉義市", "嘉義縣", "台南市", "高雄市", "屏東縣", "台東縣", "花蓮縣", 
        "宜蘭縣", "澎湖縣", "金門縣", "連江縣");

密碼

  • varchar at least eight (8) characters[19]

雜湊碼 (hash value)

Retrieve the hash value from string or file content

PHP:

<?php
/* Create a file to calculate hash of */
file_put_contents('example.txt', 'The quick brown fox jumped over the lazy dog.');

echo hash_file('sha256', 'example.txt');
// expected result: 68b1282b91de2c054c36629cb8dd447f12f096d3e3c587978dc2248444633483
// 64 characters

// calculate the hash of string
echo hash('sha256', 'The quick brown fox jumped over the lazy dog.');
?>

MySQL:

SELECT SHA2('The quick brown fox jumped over the lazy dog.', 256)

Retrieve the hash value from binary value

  • PHP: bin2hex() e.g. echo bin2hex(hex2bin(hash('sha256', 'The quick brown fox jumped over the lazy dog.')));
  • MySQL: Hexadecimal Literals e.g. SELECT HEX(UNHEX(SHA2('The quick brown fox jumped over the lazy dog.', 256)));[22]

membership

商品序號或商品條碼

MySQL: VARCHAR(14)

書籍

國際電話號碼

使用 Google libphonenumber 套件驗證國際電話號碼格式 – Frochu – Medium

很長的文字

  • MySQL: LONGTEXT: 4GB / TEXT: 65,535 bytes ~64kb [23][24]
  • MsSQL: NVARCHAR(max): 2GB [25]
 (left blank intentionally)
* data
** data type
** ex:
** range/limit:

comparision of datatypes in different database server

numeric

bigint

text

Storing Unicode text[28]

  • MySQL: varchar / MS SQL 2008: nvarchar
  • MySQL: LONGTEXT (4GB)[29] / MS SQL 2008: nvarchar(max) (2GB)[30]

date and time

DATETIME: ex: "2013-06-13 03:33:33"

  • MS SQL 2008 & MySQL are equivalent

TIMESTAMP: MS SQL 2008 and MySQL are NOT equivalent[31] Icon_exclaim.gif

  • MS SQL 2008[32] ex: 0x00000000000007D3
  • MySQL ex: 2013-06-13 03:33:33

further reading

tools

ER圖(entity-relationship diagram)

產生資料庫結構表格文件

參考其他資料表的結構設計[33]

  • DESCRIBE table_name;

references

  1. 最年長者 - 維基百科,自由的百科全書: 「根據金氏世界紀錄大全紀錄的最長壽者是活了122年的雅娜·卡爾曼特」、[https://zh.wikipedia.org/zh-tw/%E5%90%84%E5%9B%BD%E4%BA%BA%E5%8F%A3%E9%A2%84%E6%9C%9F%E5%AF%BF%E5%91%BD%E5%88%97%E8%A1%A8 各國人口預期壽命列表
  2. Type df -aT to list the file system types in Linux
  3. Comparison of file systems - Wikipedia, the free encyclopedia
  4. Naming Files, Paths, and Namespaces (Windows)
  5. Datatype for storing ip address in SQL Server - Stack Overflow
  6. Help:Range blocks - MediaWiki
  7. PostgreSQL: Documentation: Manuals: Network Address Types
  8. sql - Best database field type for a URL - Stack Overflow
  9. 中國新聞網 (2010). 台灣“獨一姓氏”者達149人 最長姓名有13個字_台灣頻道_新浪網-北美
  10. 姓名8個字 外交部不給護照 - 生活 - 自由時報電子報
  11. MySQL :: MySQL 5.0 Reference Manual :: 11.3.2 The TIME Type
  12. 各級學校名錄--教育部統計處 Department of Statistics[Last visited: 2012-02-16]
  13. mysql - What is the ideal data type for latitude / longitude? - Stack Overflow
  14. Creating a Store Locator with PHP, MySQL & Google Maps - Google Maps API Family - Google Code
  15. sql - Best Data Type for Currency - Stack Overflow[Last visited: 2012-03-07]
  16. mysql 用什么数据类型表示价格?_百度知道[Last visited: 2015-05-25]
  17. 取自中華郵政全球資訊網
  18. Password length & complexity - OWASP "Minimum length. Passwords should be at least eight (8) characters long."
  19. php - Can I use VARCHAR(32) for md5() values? - Stack Overflow
  20. mysql - How long is the SHA256 hash? - Stack Overflow
  21. insert - Storing a binary SHA1 hash into a mySQL BINARY(20) column - Stack Overflow
  22. MySQL :: MySQL 5.7 Reference Manual :: 11.1.3 String Type Overview
  23. MySQL TEXT 格式 的 長度限制 - Tsung's Blog
  24. nchar and nvarchar (Transact-SQL)
  25. int、bigint、smallint 和 tinyint (Transact-SQL)
  26. MySQL :: MySQL 5.5 Reference Manual :: 11.2.1 Integer Types (Exact Value) - INTEGER, INT, SMALLINT, TINYINT, MEDIUMINT, BIGINT
  27. Whats SQL Server NVARCHAR(max) equivalent in MySQL? - Database Administrators Stack Exchange
  28. nchar 和 nvarchar (Transact-SQL)
  29. SQL Server 2008 timestamp data type - Stack Overflow
  30. timestamp (Transact-SQL)
  31. MySQL :: MySQL 5.0 Reference Manual :: 3.4 Getting Information About Databases and Tables

further reading


Web site design and development process