Monday, 9 April 2012

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

No comments:

Post a Comment