sql subquery examples

Example 1: what is subquery in sql

SUBQUERY IS NESTED QUERY INSIDE A SELECT, 
INSERT OR UPDATE METHODS. OR INSIDE ANOTHER SUBQUERY

Example 2: why we use subquery in sql

We use subquery in order to get aggregate value in column without grouping data

Example 3: select in select sql

SELECT column1 = (SELECT column-name FROM table-name WHERE condition),       column-names  FROM table-name WEHRE condition

Example 4: subquery sql

UPDATE Book SET note= 'editore: ' + (SELECT name FROM Publisher WHERE Publisher.ID = Book.publisher)

Example 5: select in select sql

SELECT column-names  FROM table-name1 WHERE value IN (SELECT column-name                   FROM table-name2                   WHERE condition)

Example 6: subquery in sql

SUBQUERY IS NESTED QUERY INSIDE A 
SELECT, INSERT OR UPDATE METHODS.
OR INSIDE ANOTHER SUBQUERY