SQL wildcards use in Queries

SQL wildcards are used to substitute one or more characters in a string. We use SQL wildcards when we need to search for complex data. This complex data could compromise strings or numerical with special characteristics. Wildcards also come in handy when we want to speed up our querying process. The results are considerably fast when wildcards are in use. Wildcards come in handy when we need to compare the strings and also aim to get the minute details. Wildcards are put up with the LIKE operator and come in handy for solving complex queries.

SQL Wildcards Syntax

SELECT column_name
FROM table_name 
WHERE column_xxxx LIKE wildcard_operator;

Wildcard Characters in MS Access

Symbol	Description	Example
*	Represents zero or more characters	bl* finds bl, black, blue, and blob
?	Represents a single character	h?t finds a hot, hat, and hit
[]	Represents any single character within the brackets	h[oa]t finds hot and hat, but not hit
!	Represents any character, not in the brackets	h[!oa]t finds hit, but not hot and hat
–	Represents any single character within the specified range	c[a-b]t finds cat and cbt
#	Represents any single numeric character	2#5 finds 205, 215, 225, 235, 245, 255, 265, 275, 285, and 295

Wildcard Characters in SQL Server

Sr.No	Representation Symbol	Description
1	%	Stands for zero or more characters.
2	_	Stands for a single character.
3	[ ]	Stands for a single character specific to the brackets.
4	^	Stands for any character not in brackets.
5	–	Stands for a range of characters.

Here are some examples showing different LIKE operators with ‘%’ and ‘_’ wildcards:

Sr.No	Usage with LIKE operator	Description
1	WHERE columnName LIKE ‘a%’	Returns values that start with ‘a’.
2	WHERE columnName LIKE ‘%a’	Returns values that end with ‘a’.
3	WHERE columnName LIKE ‘%ab%’	Returns any value that has ‘ab’ in any position.
4	WHERE columnName LIKE ‘_a%’	Returns any value which has ‘a’ as the second character.
5	WHERE columnName LIKE ‘a_%_%’	Returns any value that starts with ‘a’ and is at least 3 characters in length.
6	WHERE columnName LIKE ‘a%x’	Returns any value which starts with ‘a’ and ends with ‘x’.

Examples of SQL Wildcards

Table - Customers 

| ID | EMPLOYEE | DEPT | CITY  | SALARY  | SALES 
| +——+----------+-----+-----------+----------+----- 
| 1 | Satvi     | HR | Chapls  | 9000.00 | 90000 
| 2 | Kannav    | MKT| BBSR    | 5000.00 | 50000 
| 3 | Kiran     | MKT| Balasore| 8000.00 | 50000 
| 4 | Lilly     | IT | Mhills  | 6000.00 | 40000 
| 5 | Alex      | IT | Whills  | 8500.00 | 80000 
| 6 | Stacy     | PR | Malibu  | 4500.00 | 20000 
| 7 | Barbie    | PR | Ventura | 1000.00 | 25000

Using the % SQL Wildcards

Example1: The following SQL statement selects all customers with a City starting with “B%”:

SELECT * FROM Customers
WHERE City LIKE ‘B%';


RESULT:

| ID | EMPLOYEE | DEPT | CITY  | SALARY  | SALES 
| +——+----------+-----+-----------+----------+----- 
| 2 | Kannav    | MKT| BBSR    | 5000.00 | 50000 
| 3 | Kiran     | MKT| Balasore| 8000.00 | 50000 

Example2: The following SQL statement selects all customers with a City containing the pattern “il”: 

SELECT * FROM Customers
WHERE City LIKE '%il%';


RESULT:

| ID | EMPLOYEE | DEPT | CITY  | SALARY  | SALES 
| +——+----------+-----+-----------+----------+----- 
| 4 | Lilly     | IT | Mhills  | 6000.00 | 40000 
| 5 | Alex      | IT | Whills  | 8500.00 | 80000 

Using the _ SQL Wildcards

Example1: The following SQL statement selects all customers with a City starting with any character, followed by “hills”:

SELECT * FROM Customers
WHERE City LIKE '_hills';


RESULT:

| ID | EMPLOYEE | DEPT | CITY  | SALARY  | SALES 
| +——+----------+-----+-----------+----------+----- 
| 4 | Lilly     | IT | Mhills  | 6000.00 | 40000 
| 5 | Alex      | IT | Whills  | 8500.00 | 80000 

Example2: The following SQL statement selects all customers with a City has 2nd character with “h”, followed by any two characters, followed by “ls”:

SELECT * FROM Customers
WHERE City LIKE ‘_h_ _ls’;


RESULT:

| ID | EMPLOYEE | DEPT | CITY  | SALARY  | SALES 
| +——+----------+-----+-----------+----------+----- 
| 1 | Satvi     | HR | Chapls  | 9000.00 | 90000 
| 4 | Lilly     | IT | Mhills  | 6000.00 | 40000 
| 5 | Alex      | IT | Whills  | 8500.00 | 80000 

Using the [charlist] SQL Wildcards

Example1: The following SQL statement selects all customers with a City starting with “B”, or “M”:

SELECT * FROM Customers
WHERE City LIKE '[BM]%';


RESULT:

| ID | EMPLOYEE | DEPT | CITY  | SALARY  | SALES 
| +——+----------+-----+-----------+----------+----- 
| 2 | Kannav    | MKT| BBSR    | 5000.00 | 50000 
| 3 | Kiran     | MKT| Balasore| 8000.00 | 50000 
| 4 | Lilly     | IT | Mhills  | 6000.00 | 40000 
| 6 | Stacy     | PR | Malibu  | 4500.00 | 20000 

Example2: The following SQL statement selects all customers with a City starting with “A”, “B”, or “C”:

SELECT * FROM Customers
WHERE City LIKE ‘[A-C]%';


RESULT:

| ID | EMPLOYEE | DEPT | CITY  | SALARY  | SALES 
| +——+----------+-----+-----------+----------+----- 
| 1 | Satvi     | HR | Chapls  | 9000.00 | 90000 
| 2 | Kannav    | MKT| BBSR    | 5000.00 | 50000 
| 3 | Kiran     | MKT| Balasore| 8000.00 | 50000 

Using the [!charlist] SQL Wildcards

The two following SQL statements select all customers with a City NOT starting with “B”, or “M”:

SELECT * FROM Customers
WHERE City LIKE ‘[!BM]%';

or 

SELECT * FROM Customers
WHERE City NOT LIKE ‘[BM]%';



RESULT:

| ID | EMPLOYEE | DEPT | CITY  | SALARY  | SALES 
| +——+----------+-----+-----------+----------+----- 
| 1 | Satvi     | HR | Chapls  | 9000.00 | 90000 
| 4 | Lilly     | IT | Mhills  | 6000.00 | 40000 
| 6 | Stacy     | PR | Malibu  | 4500.00 | 20000 

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