Joins in MySQL
Hello and
welcome everyone. In this article, we will learn about the Joins and its type
with example. Let’s go.
What is the Join?
The MySQL
Joins is used to retrieving data or records from two or more table’s records or
data. A table is having Primary Key and Foreign Keys and it’s used with SELECT,
UPDATE, DELETE statement.
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Why use Join?
In MySQL
database, you can get the result of one by one using queries for a different
table, but joins get the result from only one query. Joins result get better
performance. Joins combine data or records from two or more table and it also
returns result where the condition is satisfied.
Following
are the different six types of Joins that provide MySQL:
Inner Join
Cross Join
Left Join
Right Join
Full Join
Inner Join
The inner join used to get records or data from both
tables. Means inner join returns matched records from both tables.
Syntax of Inner Join:
SELECT column_name_1, column_name_2, . . .
FROM table_name_1
INNER JOIN table_name_2
ON table_name_1.column_name = table_name_2.column_name;
Cross Join
The Cross join matches each row from one table to another
table all rows. Table one each row groupings with table second all records.
Syntax of Cross Join:
SELECT column_name_1, column_name_2, . . .
FROM
table_name_1
CROSS
JOIN table_name_2;
Left Join
The Left join is similar to an inner join. It returns all
records or rows from the left side table and matching records or rows from the
right side table where the join condition is satisfied. If the right side table
has no matching records then right side column returns NULL values.
The syntax for Left Join
SELECT column_name_1, column_name_2, . . .
FROM table_name_1
LEFT JOIN table_name_2
ON table_name_1.column_name =
table_name_2.column_name;
Right Join
The Right join is reverse of Left join. It returns all
records or rows from the right side table and matching records or rows from the
left side table where the join condition is satisfied. If the left side table
has no matching record then left side columns to return NULL values.
The syntax for Right Join
SELECT column_name_1, column_name_2, . . .
FROM table_name_1
RIGHT JOIN table_name_2
ON table_name_1.column_name =
table_name_2.column_name;
Full Join
The Full join it returns records or rows that matched both
the right side table and left side table. Full join return very large records
or rows data in result sets.
Syntax for Full Join:
SELECT column_name_1, column_name_2, . . .
FROM table_name_1
FULL JOIN table_name_2
ON table_name_1.column_name =
tbale_name_2.column_name
WHERE ( condition );
In this article, we learned
about MySQL Joins and join types.
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