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You can use cross join on that table a few times to a get a result with however many rows you need, and each row will be numbered appropriately. This has a number of uses. For example, you can combine it with a dateadd() function to get a set for every day in a given year.
29 Μαρ 2018 · @screechOwl - An INNER JOIN takes every row in the left hand table (t1) and matches it against every row in the right hand table (t2) where the join predicate (t1.Month = t2.Month) evaluates to TRUE. I strongly recommend simply going through a basic SQL Tutorial which will elaborate on the for you. –
29 Ιαν 2014 · and I want to cross-join the table with the list (getting a new table which has 4 time as many rows as the original table and an extra val column), do I have a better option than creating an explicit temp table? What I can do is: select a.*, b.val from mytable a cross join (select stack(4,1,2,3,4) as (val) from (select * from mytable limit 1) z) b;
What is SQL JOIN? SQL JOIN is a method to retrieve data from two or more database tables. What are the different SQL JOINs ? There are a total of five JOINs. They are : 1. JOIN or INNER JOIN 2. OUTER JOIN 2.1 LEFT OUTER JOIN or LEFT JOIN 2.2 RIGHT OUTER JOIN or RIGHT JOIN 2.3 FULL OUTER JOIN or FULL JOIN 3. NATURAL JOIN 4. CROSS JOIN 5. SELF ...
To the comments as to the utility of cross joins, there is one very useful and valid example of using cross joins or commas in the admittedly somewhat obscure world of Postgres generate_series and Postgis spatial sql where you can use a cross join against generate_series to extract the nth geometry out of a Geometry Collection or Multi-(Polygon ...
select A.id aid,B.id bid from A inner join B on a.id <= b.id union select B.id,A.id from A inner join B on b.id < a.id If you wanted to be more sophisticated: select distinct case when a.id<=b.id then a.id else b.id end id1, case when a.id<=b.id then b.id else a.id end id2 from A cross join B
19 Μαρ 2023 · The first one isn't ANSI SQL. I know that Microsoft has recommended moving to the syntax of your second example. MySQL may do the same now that they are corporate. Also, the first one isn't a cross join. A cross join would be if you left out the where clause. –
I'm not sure about what you want to accomplish, but the syntax for a full cartesian product (cross join) is select * from table1, table2. If you don't want to cross everything but only some columns, something like. SELECT * FROM (select id from details) b, (select detail from details) c ; should work:
12 Ιουλ 2010 · Cross join :Cross Joins produce results that consist of every combination of rows from two or more tables. That means if table A has 3 rows and table B has 2 rows, a CROSS JOIN will result in 6 rows. There is no relationship established between the two tables – you literally just produce every possible combination.
20 Ιαν 2014 · Full outer join. From A full outer join B is the equivalent of (A − B) ∪ (A ∩ B) ∪ (B − A). Each A and each B will appear at least once. If an A matches multiple Bs it will be repeated once per match; if a B matches multiple As it will be repeated once per match. Cross Join. From A cross join B is produces the cartesian product A × B ...
