1/*Two tables: CUSTOMERS table and ORDERS table.
2ORDERS table contains STATUS attribute.*/
3SELECT
4 customers.customerNumber,
5 customerName,
6 orderNumber,
7 status
8FROM
9 customers
10LEFT JOIN orders ON
11 orders.customerNumber = customers.customerNumber;
1SELECT table1.column1, table2.column2...
2FROM table1
3LEFT JOIN table2
4ON table1.common_field = table2.common_field;
5
1-- LEFT OUTER JOIN is equivalent to LEFT JOIN
2-- b.VALUE1 is null when ID not in table2 (idem for c.VALUE1 in table3)
3SELECT a.ID, a.NAME, b.VALUE1, c.VALUE1 FROM table1 a
4 LEFT OUTER JOIN table2 b ON a.ID = b.ID
5 LEFT OUTER JOIN table3 c ON a.ID = c.ID
6WHERE a.ID >= 1000;
7
8-- ⇓ Test it ⇓ (Fiddle source link)
1SELECT bk1.book_name,bk1.isbn_no,bk1.book_price,bk1.pub_lang
2FROM book_mast bk1
3LEFT JOIN book_mast bk2 ON bk1.book_price<bk2.book_price
4WHERE bk2.pub_lang='German';
1SELECT
2 Student_details.*,
3 Attendance.*
4FROM
5 Student_details
6LEFT JOIN Attendance ON
7 Student_details.s_id = Attendance.s_id;