Structured Query Language tutorial (wildcard)

Wildcard :

SQL wildcards can substitute for one or more characters when searching for data in a database.

SQL wildcards must be used with the SQL LIKE operator.

With SQL, the following wildcards can be used:

Wildcard Description
% A substitute for zero or more characters
_ A substitute for exactly one character
[charlist] Any single character in charlist
[^charlist]
or

[!charlist]

Any single character not in charlist

SQL Wildcard Examples

We have the following "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

Using the % Wildcard

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

We use the following SELECT statement:

SELECT * FROM Persons
WHERE City LIKE 'sa%'


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 "nes" from the "Persons" table.

We use the following SELECT statement:

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


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

Using the _ Wildcard

Now we want to select the persons with a first name that starts with any character, followed by "la" from the "Persons" table.

We use the following SELECT statement:

SELECT * FROM Persons
WHERE FirstName LIKE '_la' 

The result-set will look like this:

P_Id LastName FirstName Address City
1 Hansen Ola Timoteivn 10 Sandnes

Next, we want to select the persons with a last name that starts with "S", followed by any character, followed by "end", followed by any character, followed by "on" from the "Persons" table.

We use the following SELECT statement:

SELECT * FROM Persons
WHERE LastName LIKE 'S_end_on'

The result-set will look like this:

P_Id   LastName FirstName Address City
2 Svendson   Tove Borgvn 23 Sandnes

Using the [charlist] Wildcard

Now we want to select the persons with a last name that starts with "b" or "s" or "p" from the "Persons" table.

We use the following SELECT statement:

SELECT * FROM Persons
WHERE LastName LIKE '[bsp]%'


The result-set will look like this:

P_Id LastName FirstName Address City
2 Svendson Tove Borgvn 23 Sandnes
3 Pettersen Kari Storgt 20      Stavanger


Next, we want to select the persons with a last name that do not start with "b" or "s" or "p" from the "Persons" table.

We use the following SELECT statement:

SELECT * FROM Persons
WHERE LastName LIKE '[!bsp]%'
The result-set will look like this:

P_Id LastName FirstName Address    City
1 Hansen Ola Timoteivn 10   Sandnes