Explain Like Keyword in SQL with Example

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LIKE Keyword

There may be a situation where you wanna fetch records from a table that presents a desirable character or word of  your choice in a field, suppose you need all those records in which addresses belong to a particular City, which cannot be grabbed by using assignment operator (‘=’) because an address includes street name,locality, pin code and then City name. To get the address of a specific city name, we can pull it from table by ‘LIKE’ keyword.
For Example:-

| NAME |                 ADDRESS                       |
| xyz       |  1-A,satluj Road,Janakpuri, Delhi    |

You cannot fetch it by = operator:
SELECT * FROM TableName WHERE address =’DELHI’;
For this LIKE operator is used.
LIKE keyword is used to find out all those rows that satisfy a  matching patterns in a field.
In Other word, LIKE keyword’s job is to find out a given pattern in a particular field.
However, it doesn’t do the job all alone, a wildcard comes up with it.
A wildcard provides flexibility to find out any word or set of words from a field in a table.

There are basically two wildcards :

1) %  (percentage sign) :– It is used in place of unknown sequence of characters .
2) _ (underscore sign):– It is  used in place of only a single not known character.

Both can be used at start, middle and end of the given sequence of characters.

PatternsLengthUse
   ‘xyz%’Can be of anythingIt gets all those sentences or words that start with ‘xyz’
   ‘%xyz’Can be of anythingIt gets all those sentences or words that end up with ‘xyz’
‘%xyz%’Can be  of anythingIt finds all the sentences or words in which ‘xyz’ in between
“x%z”3 (2 character + 1 Underscore)It finds all the sentences or words in whose first character would be ‘x’ and last character would be z, and anything can have in between these
‘_yz’3 (2 character + 1 Underscore)It fetches all the sequence of characters whose first character can be anything and ends with yz
‘xy_’3 (2 character + 1 Underscore)It fetches all the sequence of characters whose last character can be anything and starts with xy
‘x_z’3 (2 character + 1 Underscore)It fetches all the sequence of characters whose middle character can be anything that is in between x and y

Note: Underscore stands for only a single character while percentage can be any number of characters


Syntax:
SELECT columns,columns1… FROM tableName WHERE Column LIKE ‘Pattern’;

For Example:

Suppose I have the following table:-

1. Find all those records whose addresses which belong to DELHI

Query:  SELECT * FROM employees WHERE address LIKE ‘%delhi’;

2. Find all those records whose addresses consists of XYZ
Query:  SELECT * FROM employees WHERE address LIKE ‘xyz%’;

3. Find all records whose name’s first character can be anything but ends with ‘ohn’
Query:  SELECT * FROM employees WHERE address LIKE ‘_ohn’;

4. Find all records whose name’s last character can be anything but starts with ‘joh’
Query:  SELECT * FROM employees WHERE address LIKE ‘joh_’;

 

This post was last modified on July 4, 2022

Sandeep Verma

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Sandeep Verma
Tags: Explain Like Keyword in SQL with Example keywords like commands like keyword sql wildcards