Data type

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

file name

file name for Win   FTFS ; Linux   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:

地址

  • 資料類型: TEXT or VARCHAR(255)[14]
  • 參考別人: 觀察 Google payment 付款地址的文字輸入框並沒有限制文字長度

經緯度 (經度,緯度)

  • DECIMAL(18,12)[15] or FLOAT( 10, 6 )[16] or VARCHAR( 30 )
  • ex: 37.401724,-122.114646
  • range/limit:

價錢/金額

  • DECIMAL(10,2)[17][18]
  • 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[19]

$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[20]

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)));[24]

membership

台灣公司統一編號

  • 八位數字 因為可能以 0 開頭,所以建議使用 VARCHAR(8),而不建議使用 INT(8) [25][26]

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 [27][28]
  • MsSQL: NVARCHAR(max): 2GB [29]
 (left blank intentionally)
* data
** data type
** ex:
** range/limit:

comparision of datatypes in different database server

numeric

bigint

text

Storing Unicode text[32]

  • MySQL: varchar / MS SQL 2008: nvarchar
  • MySQL: LONGTEXT (4GB)[33] / MS SQL 2008: nvarchar(max) (2GB)[34]

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[35] Icon_exclaim.gif

  • MS SQL 2008[36] 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[37]

  • 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. address
  14. mysql - What is the ideal data type for latitude / longitude? - Stack Overflow
  15. Creating a Store Locator with PHP, MySQL & Google Maps - Google Maps API Family - Google Code
  16. sql - Best Data Type for Currency - Stack Overflow[Last visited: 2012-03-07]
  17. mysql 用什么数据类型表示价格?_百度知道[Last visited: 2015-05-25]
  18. 取自中華郵政全球資訊網
  19. Password length & complexity - OWASP "Minimum length. Passwords should be at least eight (8) characters long."
  20. php - Can I use VARCHAR(32) for md5() values? - Stack Overflow
  21. mysql - How long is the SHA256 hash? - Stack Overflow
  22. 魚乾的筆記本: MD5被破解了,要改用SHA
  23. insert - Storing a binary SHA1 hash into a mySQL BINARY(20) column - Stack Overflow
  24. 公示資料查詢服務-財政部稅務入口網
  25. » 營利事業統一編號驗證完全手冊(Javascript,Java,C#,PHP) - Hero Think~用手摀住我的嘴
  26. MySQL :: MySQL 5.7 Reference Manual :: 11.1.3 String Type Overview
  27. MySQL TEXT 格式 的 長度限制 - Tsung's Blog
  28. nchar and nvarchar (Transact-SQL)
  29. int、bigint、smallint 和 tinyint (Transact-SQL)
  30. MySQL :: MySQL 5.5 Reference Manual :: 11.2.1 Integer Types (Exact Value) - INTEGER, INT, SMALLINT, TINYINT, MEDIUMINT, BIGINT
  31. Whats SQL Server NVARCHAR(max) equivalent in MySQL? - Database Administrators Stack Exchange
  32. nchar 和 nvarchar (Transact-SQL)
  33. SQL Server 2008 timestamp data type - Stack Overflow
  34. timestamp (Transact-SQL)
  35. MySQL :: MySQL 5.0 Reference Manual :: 3.4 Getting Information About Databases and Tables

further reading


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