27. SQL JOIN QUERIES SQL joins are used to query data from two or more tables, based on a relationship between certain columns in these tables.
28. Inner Join The INNER JOIN keyword return rows when there is at least one match in both tables. Syntax SELECT column_name(s)FROM table_name1INNER JOIN table_name2ON table_name1.column_name=table_name2.column_name
29. Outer Join The OUTER JOIN clause differs from the INNER JOIN in that rows are returned even when there are no matches through the JOIN critieria on the second table. Difference Explained: Assuming you're joining on columns with no duplicates, which is by far the most common case: An inner join of A and B gives the result of A intersect B, i.e. the inner part of a venn diagram intersection. An outer join of A and B gives the results of A union B, i.e. the outer parts of a venn diagram union.
30. Left Outer Join The LEFT JOIN keyword returns all rows from the left table (table_name1), even if there are no matches in the right table (table_name2) Syntax SELECT column_name(s)FROM table_name1LEFT JOIN table_name2ON table_name1.column_name=table_name2.column_name
31. Right Outer Join The RIGHT JOIN keyword Return all rows from the right table (table_name2), even if there are no matches in the left table (table_name1) Syntax SELECT column_name(s)FROM table_name1RIGHT JOIN table_name2ON table_name1.column_name=table_name2.column_name
32. Full Join The FULL JOIN keyword return rows when there is a match in one of the tables. Syntax SELECT column_name(s)FROM table_name1FULL JOIN table_name2ON table_name1.column_name=table_name2.column_name
