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When should a subquery be nested in a HAVING clause?
If a subquery is nested in a HAVING clause, the subquery must be on the right side of the comparison operator. A group function can be used in a(n) inline view. Single-row operators can be used with multiple-row subqueries that return only one column of results.
How do you write a subquery in insert statement?
Subqueries with the INSERT Statement Subqueries also can be used with INSERT statements. The INSERT statement uses the data returned from the subquery to insert into another table. The selected data in the subquery can be modified with any of the character, date or number functions.
How are subqueries used in the HAVING clause?
The power of using a subquery in the HAVING clause is now you don’t have to hard-code values within the comparisons. You can rely on the subquery’s results to do so for you. For example, it is now possible to compare the average of a group to the overall average.
Which is an example of a subquery in SQL?
SQL subquery is a nested inner query enclosed within the main SQL query usually consisting of INSERT, UPDATE, DELETE and SELECT statements, generally embedded within a WHERE, HAVING or FROM clause along with the expression operators such as =, NOT IN, <, >, >=, <=, IN, EXISTS, BETWEEN, etc., used primarily for solving complex use cases
How are subqueries nested in a statement in SQL Server?
SQL Server implicitly qualifies the column in the subquery with the table name in the outer query. A subquery can itself include one or more subqueries. Any number of subqueries can be nested in a statement. The following query finds the names of employees who are also sales persons. Here is the result set.
What happens if column does not exist in subquery?
If a column is referenced in a subquery that does not exist in the table referenced by the subquery’s FROM clause, but exists in a table referenced by the outer query’s FROM clause, the query executes without error. SQL Server implicitly qualifies the column in the subquery with the table name in the outer query. Multiple levels of nesting