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What can be used instead of left outer join?
But to answer your question, there is a way to achieve the same results, by using a UNION query of an INNER join and a NOT EXISTS subquery. That’s because in a LEFT OUTER JOIN, conditions on the right table (the B table in this case) must be placed in the ON clause of the join, and not the WHERE clause.
What can replace right outer join?
You can always replace a RIGHT OUTER JOIN with a LEFT OUTER JOIN that produces the same answer, and vice-versa. –
What can be used instead of join in SQL?
A subquery can be used instead of a join whenever only one column is required from the other table. (Recall that subqueries can only return one column.) In this example, you only needed the CompanyName column, so the join could be changed into a subquery.
When to use an outer join?
An outer join is used to return results by combining rows from two or more tables. But unlike an inner join, the outer join will return every row from one specified table, even if the join condition fails.
What is LEFT OUTER JOIN in SQL?
A LEFT OUTER JOIN is one of the JOIN operations that allow you to specify a join clause. It preserves the unmatched rows from the first (left) table, joining them with a NULL row in the shape of the second (right) table.
When to use a left join?
Use a left join when you want all the results from Table A, but if Table B has data relevant to some of Table A’s records, then you also want to use that data in the same query. Use a full join when you want all the results from both Tables.
What is the difference between “inner join” and “outer join”?
Key Differences Between Inner Join and Outer Join The basic difference between the Inner Join and Outer Join is that inner join compares and combine only the matching tuples from both the tables. The database size of the resultant obtained from the Inner Join is smaller that Outer Join. There are three types of the Outer Join Left Outer Join, Righ Outer Join, and Full Outer Join.