![]() ![]() The MySQL LIKE operator is used with the WHERE clause to check whether a string contains the specified pattern or not. For these purposes, MySQL provides us with the LIKE Operator. Furthermore, what if you want to find names that end with ‘r’. Suppose you are going through a record of names and you want to find out names beginning with ‘P’. In this tutorial, you have learned how to use the PostgreSQL LIKE and ILIKE operators to query data using pattern matching.In this tutorial, we will learn about the MySQL LIKE Operator. PostgreSQL also provides some operators that act like the LIKE, NOT LIKE, ILIKE and NOT ILIKE operator as shown below: Operator If you use the LIKE operator instead, the query will not return any row. The BAR% pattern matches any string that begins with BAR, Bar, BaR, etc. For example: SELECTįirst_name ILIKE 'BAR%' Code language: SQL (Structured Query Language) ( sql ) In addition, the ILIKE operator matches value case-insensitively. PostgreSQL supports the ILIKE operator that works like the LIKE operator. ![]() The following query uses the NOT LIKE operator to find customers whose first names do not begin with Jen: SELECTįirst_name Code language: SQL (Structured Query Language) ( sql ) PostgreSQL extensions of LIKE operator The returned first names are C heryl, S herri, S herry, and T herasa. ![]() And is ended with any number of characters.And is followed by the literal string her.The pattern _her% matches any string that: You can combine the percent ( %) with underscore ( _) to construct a pattern as the following example: SELECT SELECTįirst_name Code language: SQL (Structured Query Language) ( sql ) It’s possible to use wildcards at the beginning and/or end of the pattern.įor example, the following query returns customers whose first name contains er string like Jenifer, Kimberly, etc. The fourth expression returns false because the pattern b_ matches any string that begins with the letter b and followed by any single character.The third expression returns true because the pattern ( _o_) matches any string that begins with any single character, followed by the letter o and ended with any single character. ![]() The second expression returns true because it matches any string that begins with the letter f and followed by any number of characters.The first expression returns true because the foopattern does not contain any wildcard character so the LIKE operator acts like the equal ( =) operator.See the following example: SELECT 'foo' LIKE 'foo', - true 'foo' LIKE 'f%', - true 'foo' LIKE '_o_', - true 'bar' LIKE 'b_' - false Code language: SQL (Structured Query Language) ( sql ) Let’s take some examples of using the LIKE operator Simple PostgreSQL LIKE examples PostgreSQL LIKE operator – pattern matching examples If the pattern does not contain any wildcard character, the LIKE operator behaves like the equal ( =) operator. The NOT LIKE operator returns true when the value does not match the pattern. To negate the LIKE operator, you use the NOT operator as follows: value NOT LIKE pattern Code language: SQL (Structured Query Language) ( sql ) The expression returns true if the value matches the pattern. The syntax of PostgreSQL LIKE operator is as follows: value LIKE pattern Code language: SQL (Structured Query Language) ( sql ) Underscore sign ( _) matches any single character.Percent sign ( %) matches any sequence of zero or more characters.PostgreSQL provides you with two wildcards: You construct a pattern by combining literal values with wildcard characters and use the LIKE or NOT LIKE operator to find the matches. This technique is called pattern matching. The query returns rows whose values in the first_name column begin with Jen and may be followed by any sequence of characters. Notice that the WHERE clause contains a special expression: the first_name, the LIKE operator and a string that contains a percent sign (%). However, this process can be time-consuming if the customer table has a large number of rows.įortunately, you can use the PostgreSQL LIKE operator to match the first name of the customer with a string using the following query: SELECTįirst_name LIKE 'Jen%' Code language: SQL (Structured Query Language) ( sql ) How do you find the exact customer from the database? You may find the customer in the customer table by looking at the first name column to see if there is any value that begins with Jen. However, you can recall that her name begins with something like Jen. Suppose that you want to find a customer, but you don’t remember her name exactly. Summary: in this tutorial, you will learn how to use the PostgreSQL LIKE and ILIKE operators to query data using pattern matchings. ![]()
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