A. Inner Join
The INNER JOIN keyword selects all rows from both the tables as long as the condition is satisfied.
This keyword will create the result-set by combining all rows from both the tables where the condition satisfies i.e value of the common field will be the same.
Syntax: Example Queries(INNER JOIN) This query will show the names and age of students en.
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B. Left Join
This join returns all the rows of the table on the left side of the join and matches rows for the table on the right side of the join.
For the rows for which there is no matching row on the right side, the result-set will contain null.
LEFT JOIN is also known as LEFT OUTER JOIN.
Syntax: Example Queries(LEFT JOIN): Output:
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C. Right Join
RIGHT JOIN is similar to LEFT JOIN.
This join returns all the rows of the table on the right side of the join and matching rows for the table on the left side of the join.
For the rows for which there is no matching row on the left side, the result-set will contain null.
RIGHT JOIN is also known as RIGHT OUTER JOIN.
Syntax: Example Queries(RIGHT JO.
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D. Full Join
FULL JOIN creates the result-set by combining results of both LEFT JOIN and RIGHT JOIN.
The result-set will contain all the rows from both tables.
For the rows for which there is no matching, the result-set will contain NULLvalues.
Syntax: Example Queries(FULL JOIN): Output: Left JOIN (Video) Right JOIN (Video) Full JOIN (Video) SQL | JOIN (Cartesi.
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How do I specify a join condition in SQL Server?
Inner joins can be specified in either the FROM or WHERE clauses.
Outer joins and cross joins can be specified in the FROM clause only.
The join conditions combine with the WHERE and HAVING search conditions to control the rows that are selected from the base tables referenced in the FROM clause.
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What is a join operation in relational algebra?
The operation corresponds to a join operation in relational algebra.
Informally, a join stitches two tables and puts on the same row records with matching fields:
INNER LEFT OUTER RIGHT OUTER FULL OUTER and CROSS .
To explain join types, the rest of this article uses the following tables:. ,
What is join processing?
Join processing applies to every row of the inner table where the value of its join columns satisfies the specified relational conditions with the correlating join columns of the selected row of the outer table.
This processing involves these actions:
Creates a row in the result table with the requested columns of both the inner and outer tables. ,
What is the result of a join?
The result of the join can be defined as the outcome of first taking the cartesian product (or cross join) of all rows in the tables (combining every row in table A with every row in table B) and then returning all rows that satisfy the join predicate.
