Page 152 - iPlus_Ver_2.0_class_7
P. 152

The ‘SELECT’ statement has many optional clauses which are as follows:

                  •  WHERE specifies the criteria according to which rows are retrieved.
                  •  ORDER BY specifies an order (Ascending or Descending) to return the rows.
                  The syntax to execute the SELECT queries:
                      SELECT * FROM table_name;
                  To display all the data in the table:

                      SELECT * FROM Student;
                  The preceding command will display the following output:
                                       +-----------+-----------+----------+-------+
                                       | StudentID | FirstName | LastName | Marks |
                                       +-----------+-----------+----------+-------+
                                       |     10001 | Amit      | Sharma   |   450 |
                                       |     10002 | Divya     | Kaushik  |   475 |
                                       |     10003 | Aadarsh   | Kumar    |   475 |
                                       +-----------+-----------+----------+-------+
                  To get details of the list of students whose LASTNAME is Kumar:
                      SELECT * FROM Student WHERE LastName = "Kumar";
                  The preceding command will display the following output:
                                       +-----------+-----------+----------+-------+
                                       | StudentID | FirstName | LastName | Marks |
                                       +-----------+-----------+----------+-------+
                                       |     10003 | Aadarsh   | Kumar    |   475 |
                                       +-----------+-----------+----------+-------+

                  To get details of the list of students in ascending order of FirstName:
                      SELECT * FROM Student ORDER BY FirstName ASC;
                  The preceding command will display the following output:
                                       +-----------+-----------+----------+-------+
                                       | StudentID | FirstName | LastName | Marks |
                                       +-----------+-----------+----------+-------+
                                       |     10003 | Aadarsh   | Kumar    |   450 |
                                       |     10002 | Divya     | Kaushik  |   480 |
                                       |     10001 | Amit      | Sharma   |   475 |
                                       +-----------+-----------+----------+-------+
                  We  can  also  us  the  wildcards  (*  and  %)  with  the  SELECT  command  to  specify  conditions.
                  The * wildcard denotes a single character, on the other hand the % wildcard denotes the multiple
                  characters:
                      SELECT FirstName, Marks FROM Student WHERE LastName like 'K%';
                                                      +-----------+-------+
                                                      | FirstName | Marks |
                                                      +-----------+-------+
                                                      | Divya     |   480 |
                                                      | Aadarsh   |   475 |
                                                      +-----------+-------+

                      SELECT Marks FROM Student WHERE FirstName like 'A%';
                                                              +-------+
                                                              | Marks |
                                                              +-------+
                                                              |   450 |
                                                              +-------+



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