tailieunhanh - Oracle XSQL- P10

Oracle XSQL- P10Welcome 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. | 160 Chapter 8 Table Set Comparison Operators OPERATOR DESCRIPTION EXAMPLE IN Tests if an operand belongs to the specified set. SELECT ename FROM emp WHERE sal IN 800 950 1100 NOT IN Tests if an operand doesn t belong to the specified set. SELECT ename FROM emp WHERE sal NOT IN 800 950 1100 ANY Used in conjunction with a relationship comparison operator. Determines if the specified relationship is true for any of the values. SELECT ename FROM emp WHERE sal ANY 800 950 1100 SOME Used in conjunction with a relationship comparison operator. Determines if the specified relationship is true for one or more of the values. SELECT ename FROM emp WHERE sal SOME 800 950 1100 ALL Used in conjunction with a relationship comparison operator. Determines if the specified relationship is true for all of the values. SELECT ename FROM emp WHERE sal ALL 800 950 1100 The Imaginary Dual Table Oracle provides the dual table an imaginary table used largely for allowing you to perform functions. For instance if you want to use a select statement to get the current date you could do so as follows SELECT sysdate FROM dual Table Set Operators OPERATOR DESCRIPTION UNION All unique rows of both queries are returned. UNION ALL All rows of both queries are returned. MINUS Eliminates rows that appear in the second query from the rows returned in the first query. INTERSECT Returns only the rows that are common to both queries. Oracle SQL 161 Of course to do this from XSQL requires that you perform the following xml version page connection demo xmlns xsql urn oracle-xsql xsql query SELECT sysdate AS Date FROM dual xsql query page You can also use the dual table to include parameters in the result set xml version page connection demo xmlns xsql urn oracle-xsql xsql query select @param AS ParamName FROM dual xsql query page Managing Tables The select statement is the tool used for getting data out of the database. The flip side of select is getting data in to the database. Before you