1. Please describe, in a short 1-2 paragraph answer, just how a “Correlated Subq

Question

1. Please describe,  in a short 1-2 paragraph answer, just how a “Correlated Subquery “ actual works.  How does the inner query interact with the outer query?  Just how many times does the inner query actually execute, etc.

2. Explain how ‘EXISTS’ works with Subqueries.

3. Which is better, joins or Subqueries?  Maybe give some advantages and disadvantages of each…

4. Please explain how ‘any’ and ‘all’ maybe used with subqueries.

5. Can Subqueries be used in Inserts, Deletes and/or Updates? Please explain.

Explanation / Answer

Hi Dear,

Please find my answer for Q2. As per the chegg guideline, please post one question per post.

2. Explain how ‘EXISTS’ works with Subqueries.

The EXISTS operator is used to test for the existence of any record in a subquery.

The EXISTS operator returns true if the subquery returns one or more records.

EXISTS Syntax:

SELECT column_name(s)
FROM table_name
WHERE EXISTS
(SELECT column_name FROM table_name WHERE condition);

The following SQL statement returns TRUE and lists the suppliers with a product price less than 20:

Example
SELECT SupplierName
FROM Suppliers
WHERE EXISTS (SELECT ProductName FROM Products WHERE SupplierId = Suppliers.supplierId AND Price < 20);

Please DONT forgot to rate my answer. We are working hard for you Guys!!

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.