Sep 16, 2008 · The DUAL table is a special one-row table present by default in all Oracle database installations. It is suitable for use in selecting a pseudocolumn such as SYSDATE or USER

Feb 7, 2015 · I used the table (values('x')) DUAL(DUMMY) to retrieve the result from a query that has a single column with an ANY result (in bold what writes the framework, in italic what I put as …

Jan 9, 2011 · All database users have access to DUAL. The DUAL table has one column called DUMMY and one row containing the value X. And the SQL Reference: DUAL is a table automatically created …

Sep 17, 2010 · Is it possible to have a statement like SELECT "Hello world" WHERE 1 = 1 in SQL? The main thing I want to know, is can I SELECT from nothing, ie not have a FROM clause.

May 7, 2018 · Before 23c: Instead of DUAL, select from a pre-built collection to return multiple rows. This solution has a small syntax, avoids type conversions, and avoids potentially slow recursive …

Além disso a dual permite que você possa criar um join, ao contrario da maneira que o sql serve trabalh. No oracle é possivel faze-la duplicas as linhas, caso necessário.

6 Dual table is used to select pseudo columns. it has one row and one column DUMMY which has a value X. I have two questions What actually does a pseudo column mean? How is the dual able to …

Edit: Per Bacon Bit 's answer, it does seem required by the SQL standard. So in reality, because the name DUAL is such a misnomer, if I were to create a table and name it ATOM or ONE, e.g. create …

Dec 31, 2014 · In this case the select * from dual only exists because a multi-table INSERT statement needs a query as the source. Normally, when you're creating a multi-table INSERT, you would select …

May 18, 2015 · 20 Just use select 1. From documentation Oracle uses the "fake" dual table for many selects, where in PostgreSQL we can write select just without from part at all. This table was created …