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Tuesday, 11 October 2011

SQL LIKE Operator


The LIKE operator is used in a WHERE clause to search for a specified pattern in a column.


The LIKE Operator

The LIKE operator is used to search for a specified pattern in a column.

SQL LIKE Syntax

SELECT column_name(s)
FROM table_name
WHERE column_name LIKE pattern


LIKE Operator Example

The "Persons" table:

P_Id LastName FirstName Address City
1 Hansen Ola Timoteivn 10 Sandnes
2 Svendson Tove Borgvn 23 Sandnes
3 Pettersen Kari Storgt 20 Stavanger

Now we want to select the persons living in a city that starts with "s" from the table above.

We use the following SELECT statement:

SELECT * FROM Persons
WHERE City LIKE 's%'

The "%" sign can be used to define wildcards (missing letters in the pattern) both before and after the pattern.

The result-set will look like this:

P_Id LastName FirstName Address City
1 Hansen Ola Timoteivn 10 Sandnes
2 Svendson Tove Borgvn 23 Sandnes
3 Pettersen Kari Storgt 20 Stavanger

Next, we want to select the persons living in a city that ends with an "s" from the "Persons" table.

We use the following SELECT statement:

SELECT * FROM Persons
WHERE City LIKE '%s'

The result-set will look like this:

P_Id LastName FirstName Address City
1 Hansen Ola Timoteivn 10 Sandnes
2 Svendson Tove Borgvn 23 Sandnes

Next, we want to select the persons living in a city that contains the pattern "tav" from the "Persons" table.

We use the following SELECT statement:

SELECT * FROM Persons
WHERE City LIKE '%tav%'

The result-set will look like this:

P_Id LastName FirstName Address City
3 Pettersen Kari Storgt 20 Stavanger

It is also possible to select the persons living in a city that does NOT contain the pattern "tav" from the "Persons" table, by using the NOT keyword.

We use the following SELECT statement:

SELECT * FROM Persons
WHERE City NOT LIKE '%tav%'

The result-set will look like this:

P_Id LastName FirstName Address City
1 Hansen Ola Timoteivn 10 Sandnes
2 Svendson Tove Borgvn 23 Sandnes
 

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