Page 58 - Modular_V2.0_SQL_Flipbook

LEARNERS

Learner_id Learner_name Subject

101 Aarav Science

102 Meera Commerce

104 Rahul Arts

SELECT STAFF.Staff_name, LEARNERS.Learner_name, LEARNERS.Subject

FROM STAFF
INNER JOIN LEARNERS
ON STAFF.Staff_id = LEARNERS.Learner_id;

Output:
+------------+--------------+----------+
| Staff_name | Learner_name | Subject |
+------------+--------------+----------+
| Rohit | Aarav | Science |
+------------+--------------+----------+
| Amisha | Meera | Commerce |
+------------+--------------+----------+

OUTER JOIN

An OUTER JOIN returns all the rows from one table and the matching rows from the other table. If
there is no matching row in the other table, the result will still include the row but with NULL (no

value) for columns from the table that doesn’t have a match.
There are two main types of Outer Joins:
LEFT JOIN
1. Left Outer Join (LEFT JOIN): It shows all rows from the left table and
the matching rows from the right table. If there is no match, it shows

NULL for the right table’s columns. Table 1 Table 2
Syntax:

SELECT table1.column1, table2.column2

FROM table1
LEFT JOIN table2

ON table1.common_column = table2.common_column;
Example using tables: STAFF and LEARNERS

SELECT STAFF.Staff_name, LEARNERS.Learner_name, STAFF.Location
FROM STAFF

LEFT JOIN LEARNERS
ON STAFF.Staff_id = LEARNERS.Learner_id;

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