TAILIEUCHUNG - Oracle XSQL- P6
Oracle XSQL- P6Welcome to the exciting world of eXtended Structured Query Language (XSQL) development! What’s so exciting? Efficiency and ease of use. XSQL isn’t some razzle-dazzle technology to wow your users. It also isn’t the latest X standard du jour that no one can stop talking about until you ask, “But what does it do for me today?” The problem with all of the great stuff out there is that no one technology does it all. | 80 Chapter 5 EMPLOYEES_ROW EMPLOYEES ROW ROWSET Oracle objects and collections also appear as nested structures in the canonical representation. The following example shows a single row with an object and a collection ROWSET ROW num 1 YOUR_OBJECT_COLUMN_NAME ATTRIBUTE1 Value1 ATTRIBUTE1 ATTRIBUTE2 Value2 ATTRIBUTE2 YOUR_OBJECT_COLUMN_NAME YOUR_COLLECTION_NAME YOUR_COLLECTION_NAME_ITEM ATTRIBUTE1 Value1 ATTRIBUTE1 ATTRIBUTE2 Value2 ATTRIBUTE2 YOUR_COLLECTION_NAME_ITEM YOUR_COLLECTION_NAME_ITEM ATTRIBUTE1 Value1 ATTRIBUTE1 ATTRIBUTE2 Value2 ATTRIBUTE2 YOUR_COLLECTION_NAME_ITEM YOUR_COLLECTION_NAME ROW ROWSET Formatting Dates Because most applications use dates at some point it is very important to understand how XSQL works with dates. XSQL uses date formats that act as masks. A date format is a combination of different symbols that represent different parts of the date-time stamp. XSQL uses date formats both when retrieving information from the database and when putting information into it. When retrieving information XSQL writes the date to output in accordance with the date format. When inputting information it assumes that dates are in the format specified by the date format. The characters that represent different parts of the date format are listed in Table . Padding for variable-length data can be supplied by repeating the symbol. For example if you want 08 to represent 8 . you put hh in the format string. Table Date Format Symbols SYMBOL MEANING EXAMPLE G Era designator AD y Year 1996 MM Month in year as number 07 Writing XSQL Pages 81 Table Date Format Symbols Continued SYMBOL MEANING EXAMPLE MMM Month in year as word July D Day in month 10 h Hour in . . 1-12 12 H Hour in day 0-23 0 m Minute in hour 30 s Second in minute 55 S Millisecond 978 E Day in week Tuesday D Day in year 189 F Day of week in month 2 2nd Wed in July W Week in year 27 W Week in month 2 a . . marker PM k Hour in day 1 24 24 K Hour in . . 0 11 0 z Time zone .
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