|
Formats that use delimiter-separated values (also DSV)〔DSV stands for ''Delimiter Separated Values'' 〕 store two-dimensional arrays of data by separating the values in each row with specific delimiter characters. Most database and spreadsheet programs are able to read or save data in a delimited format. A delimited text file is a text file used to store data, in which each line represents a single book, company, or other thing, and each line has fields separated by the delimiter.〔 Stephen R. Westman. ("Creating Database-backed Library Web Pages: Using Open Source Tools" ). 2006. Section "Structured Text Files". p. 15. 〕 Compared to the kind of flat file that uses spaces to force every field to the same width, a delimited file has the advantage of allowing field values of any length.〔 Richard Petersen. ("Introductory Command Line Unix for Users" ). 2006. p. 356. 〕 == Delimited formats == Any character may be used to separate the values, but the most common delimiters are the comma, tab, and colon.〔〔Under UNIX, the colon is the most common DSV delimiter for values that may contain whitespace. ''Ibid''.〕 The vertical bar (also referred to as ''pipe'') and space are also sometimes used.〔 In a comma-separated values (CSV) file the data items are separated using commas as a delimiter, while in a tab-separated values (TSV) file, the data items are separated using tabs as a delimiter. Column headers are sometimes included as the first line, and each subsequent line is a row of data. The lines are separated by newlines. For example, the following fields in each record are delimited by commas, and each record by newlines: "Date","Pupil","Grade" "25 May","Bloggs, Fred","C" "25 May","Doe, Jane","B" "15 July","Bloggs, Fred","A" "15 April","Muniz, Alvin ""Hank""","A" Note the use of the double quote to enclose each field. This prevents the comma in the actual field value (Bloggs, Fred; Doe, Jane, etc.) from being interpreted as a field separator. This necessitates a way to "escape" the field wrapper itself, in this case the double quote; it is customary to double the double quotes actually contained in a field as with those surrounding "Hank". In this way, any ASCII text including newlines can be contained in a field. ASCII includes several control characters that are intended to be used as delimiters. They are: 28 for File Separator, 29 for Group Separator, 30 for Record Separator, and 31 for Unit Separator. Use of these characters has not achieved widespread adoption; some systems have replaced their control properties with more accepted controls such as CR/LF and TAB. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Delimiter-separated values」の詳細全文を読む スポンサード リンク
|