(The latter may be specified explicitly using ASC. DESC will order in descending order, otherwise ascending order is used. Vendors who do not implement this functionality may specify different treatments for Null sorting in the DBMS. Not all DBMS vendors implement this functionality, however. With the SQL:2003 extension T611, "Elementary OLAP operations", nulls can be sorted before or after all data values by using the NULLS FIRST or NULLS LAST clauses of the ORDER BY list, respectively. The SQL standard's core functionality does not explicitly define a default sort order for Nulls. (not standardized in SQL:2003) which allow the propagation of sort criteria through nested subqueries. ASC DESC: The Second, You will be using the ASC or DESC to specify whether the values in the specified column should be sorted in descending or ascending. The only exception are constructs like ORDER BY ORDER OF.
A view is a logical relational table, and the relational model mandates that a table is a set of rows, implying no sort order whatsoever. Although some database systems allow the specification of an ORDER BY clause in subqueries or view definitions, the presence there has no effect on the final result-set order, but makes sense when combined with a result offset clause or a fetch first clause. If an ordering is required, the ORDER BY must be provided in the SELECT statement sent by the application. Without this clause, the relational database system may return the rows in any order. ORDER BY is the only way to sort the rows in the result set. DESC: Sorts tha result set in descending order. The expressions are evaluated and the results are used for the sorting, i.e., the values stored in the column or the results of the function call. ASC : Sorts tha result set in ascending order.
When this attribute is omitted from the ORDER BY clause, the sort order is defaulted to ASC or ascending order. ) The sort criteria can be expressions, including column names, user-defined functions, arithmetic operations, or CASE expressions. Following on from my earlier question here Case statement for Order By clause with Desc/Asc sort I have a statement like this: SELECT FROM TableName WHERE ORDER BY CASE OrderB圜olumn WHEN 1 THEN Forename END DESC, CASE OrderB圜olumn WHEN 2 THEN Surname END ASC. The SQLite ORDER BY clause can be used without specifying the ASC or DESC modifier. The sort criteria does not have to be included in the result set (restrictions apply for SELECT DISTINCT, GROUP BY, UNION, EXCEPT and INTERSECT. An ORDER BY clause in SQL specifies that a SQL SELECT statement returns a result set with the rows being sorted by the values of one or more columns.
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