5/3/2023 0 Comments Toad 12.1 license keyThe bold aliases in the refactored SQL are added with "Add column aliases" and removed by "Remove column aliases." SELECT empno, DECODE (deptno, 10, 'New York', 20, 'Dallas', 'Chicago')ĭECODE (deptno, 10, 'New York', 20, 'Dallas', 'Chicago') COLĬonverts from proprietary Oracle join syntax to ANSI and from ANSI join syntax to the proprietary Oracle syntax.ĪNSI join syntax is cross-platform compatible and compatible with queries. Remove Subqueries Using Oracle Join Syntax Using it should execute successfully on other database systems that support the ANSI syntax. Queries are rewritten so that table joins and where clause expressions are used in place of subqueries. Notice that the original SQL includes an embedded SELECT statement. This subquery is removed in the refactored SQL, pt is referenced in the main query, and the where condition is rewritten as EMP.deptno = DEP.deptno. The above example uses Oracle join syntax. If the Remove using ANSI syntax was used, this would be the refactored SQL:įROM SCOTT.EMP EMP INNER JOIN SCOTT.DEPT DEP ON (EMP.DEPTNO = DEP.DEPTNO) Ī query may be written so that a where clause expression occurs within a subquery, and that expression does not reference any identifiers in the subquery. In the following simple example, the "WHERE.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |