What are the differences between the joining and subquery ap

What are the differences between the joining and subquery approaches to manipulating multiple tables in SQL?

Solution

Main difference is that any query that can be written using the subquery approach can also be written using the joining approach, but not vice versa. Most systems allow pairwise joining of one and one column in an inner query with one column in an outer query (With exception of EXISTS keyword). Also data can be displayed for column which are reference in outer query. If data from inner sub query results are to be included then we need to use join. Joining techniques work well when data from several relations are to be fetched and printed and the relationships are not necessarily nested.