The
DISTINCT keyword can be used to return only distinct (different) values.
In a table, some of the columns may contain duplicate values.
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In the example below, the company W3Schools is listed twice in the result-set if the keyword
DISTINCT is not used.
To select only different values from the column named Company, we use a select distinct statement.
CREATE TABLE Orders ( Company VARCHAR(32), OrderNumber NUMBER(4) NOT NULL ); Table created. INSERT INTO Orders VALUES( 'Sega', 3412 ); INSERT INTO Orders VALUES( 'W3Schools', 2312 ); INSERT INTO Orders VALUES( 'Trio', 4678 ); INSERT INTO Orders VALUES( 'W3Schools', 6798 ); SELECT Company FROM Orders; COMPANY -------------------------------- Sega W3Schools Trio W3Schools SELECT DISTINCT Company FROM Orders; COMPANY -------------------------------- Sega Trio W3Schools |
Demonstration
Below is an SQL test area from W3Schools, which uses the well-known Northwind sample database. The tables here are for read only because of the problem of embedding the scripts. For a fully working example, check this by using Chrome.
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Result:
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The Database includes:
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The Database includes:
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