The SQL SELECT DISTINCT Statement
In a table, some of the columns may contain duplicate values. This is not a problem, however, sometimes you will want to list only the different (distinct) values in a table.
The DISTINCT keyword can be used to return only distinct (different) values.
SQL SELECT DISTINCT Syntax
SELECT DISTINCT column_name(s)
FROM table_name
SELECT DISTINCT Example
The "student" table:
Student _No | Student_Name | Address | Year_Study | Sex | Date_of_birth | Course_No |
ST100 | K.Ranjan | Kandy | 1 | Male | 17/01/1988 | C1 |
ST101 | N.Kumanan | Jaffna | 2 | Male | 15/12/1989 | C2 |
ST102 | S.Ranjini | Vavuniya | 1 | Female | 17/01/1989 | C1 |
ST103 | K.Dias | Colombo | 3 | Male | 22/07/1987 | C1 |
ST104 | A.Kavitha | Matara | 3 | Female | 20/03/1985 | C2 |
ST105 | L.Lavanya | Galle | 2 | Female | 22/04/1989 | C2 |
ST106 | G.Moorthy | Jaffna | 2 | Male | 12/01/1986 | C1 |
ST107 | F.Nathan | Matara | 2 | Male | 29/01/1990 | C3 |
ST108 | A.H.M.Akmal | Puttalam | 1 | Male | 12/12/1990 | C3 |
Now we want to select only the distinct values from the column named "Address" from the table above.
We use the following SELECT statement:
SELECT DISTINCT Address FROM student;
The result-set will look like this:
+----------+
| Address |
| Kandy |
+----------+
| Jaffna |
| Matara |
| Vavuniya |
| Colombo |
| Galle |
| Puttalam |
+----------+
إرسال تعليق
Thank you for vising