| ylbtech-SQL-W3School: SQL DISTINCT statement |
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This chapter explains the SELECT DISTINCT statement.
SQL SELECT DISTINCT statement
In the table, it may contain duplicate values. This is not a problem, but sometimes you may want to just list the different (distinct) values.
DISTINCT keyword is used to return only difference values.
grammar:
SELECT DISTINCT name FROM table column names
Use DISTINCT keyword
If you want to "Company" column, select all the values, we need to use the SELECT statement:
SELECT Company FROM Orders
"Orders"表：
| Company | OrderNumber |
|---|---|
| IBM | 3532 |
| W3School | 2356 |
| Apple | 4698 |
| W3School | 6953 |
result:
| Company |
|---|
| IBM |
| W3School |
| Apple |
| W3School |
Please note, focus on results, W3School was listed twice.
For the Company "column select only difference values only , we need to use the SELECT DISTINCT statement:
SELECT DISTINCT Company FROM Orders
result:
| Company |
|---|
| IBM |
| W3School |
| Apple |
Now, in the result set, "W3School" was listed only once.
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