A natural join allows the database to attempt to determine relationships on behalf of the programmer by comparing column names and joining on those fields. It only shows columns once when they are duplicated in the tables, and operates on rows that contain matches in both tables (an "inner join").
A outer join will show results for any matching rows, even if one of the two tables does not contain a matching record. In those events, the empty table's fields will be "null", since no match was found. Depending on the type of outer join, either table a will always have a record, table b will always have a record, or either table may not have a record (but at least one record is required per row to generate a row).
Inner join is from the inside while left out join is from the outside
A natural join is a join that automatically matches columns with the same name in both tables. An equijoin is when the join condition is based on the equality of values in the specified columns. An outer join (left, right, or full) includes rows that do not have matching values in both tables, with NULL values filling in the gaps.
Joins refer to the combination of related records to form a relation . There are six types of joins in database . Types of joins are cross join, natural join , right join , left join ,Inner join, Outer join.INNER JOINOUTER JOINLEFT JOINRIGHT JOINNATURAL JOINCROSS JOINIn special cases a table can join to itself (SELF JOIN)
Full outer join will fetch at maximum 'addition of 2 tables' Ex: Table A - 2 rows; Table B - 3 rows. Full outer join will fetch in 2+3 = 5 rows. Where as in Cartesian product will fetch in 'product of 2 tables'. Ex: Table A - 2 rows; Table B - 3 rows. Full outer join will fetch in 2x3 = 6 rows
The outer circles show the difference between the two sides. The center where they join are the area they are the same. This is a great graphic way to show comparison of two things or ideas.
One is inner the other is not... Plum
Difference Between CARTESIAN PRODUCT & NATURAL JOINT Cartesian product is like the cross product ie every element of one row of one table/entity is multiplied to every column of another table for solving linked queries of two tables ... Where as natural Join is simply joining two or more entities eliminating the common attributes or columns.. @nayan answered it :)
There are varieties of JOINS, which are different by the "conditions" specified in the SQL query. We will discuss on the following types:• Natural or Equijoin• Inner• OuterNatural or EquijoinBecause Teradata SQL does not support the ANSI SQL-2003 NATURAL JOIN syntax, it treats natural and equijoins as one and the same.The natural join is an equality join (with = sign) made over a common column set with matching column names such as a primary key-foreign key relationship that is expressed in a WHERE clause. For example,WHERE A.empnum = B.empnumWhile both Natural as well as Equijoin are made over an equality condition (with = sign), the column names on which tables are joined need not match in an equijoin (but data should), while they must match in a natural join. For example, in the WHERE condition above, if there is a column present in table B with matching data and the name is emp_no then we can rewrite the query as follows:WHERE A.empnum = B.emp_noInner Joins: The inner join, most of the time referred as just JOIN, combines only the rows that have specific similarity between the joined tables (employee number in the above example). One good thing about using INNER JOINS is that one can avoid unwanted cross joins. This happens by mistake. Following types of INNER JOINS are used in SQL.Ordinary Inner JoinCross JoinSelf-JoinOuter Joins: The outer join is an extension to inner join that returns not only common rows between the tables, but also it returns rows that do NOT have anything in common. This non-matching row might be due to a NULL value or invalid data. Depending on how you code, outer join can return the inner join rows plus any of the no matching rows from the:Left Table (Left Outer Join).Right Table (Right Outer Join).Both Tables (Full Outer Join).
The Difference lies in the portions and the list of collages that you are eligible to join if you pass in the exam.
Join is used to combine related tuples from two relations . Full outer join cover all possible combinations of common tuples.
Basically Joins are used to get result from two or more tables and there are two types of joinsinner join and outer joinInner join : a join of two or more tables which omits the blank rows while checkingOuter join is subcatogorised in to left outer join and right outer join. Which includes blank rows in specifed side if condition satisfies.Simple outer join is combination of left and right outerjoins.Apart from these there areNatural join : cartisian productEqui join : which includes = operator in conditionNonEqui join : All conditional joins which doesn't uses = in there conditions.
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. Wheres as an outer join of A and B gives the results of A union B, i.e. the outer parts of a venn diagram union.