Therefore, if it's desired to match a sequence anywhere within a string, the pattern must start and end with a percent sign. LIKE pattern matching always covers the entire string. An underscore ( _) in pattern stands for (matches) any single character a percent sign ( %) matches any sequence of zero or more characters. If pattern does not contain percent signs or underscores, then the pattern only represents the string itself in that case LIKE acts like the equals operator. An equivalent expression is NOT ( string LIKE pattern).) (As expected, the NOT LIKE expression returns false if LIKE returns true, and vice versa. The LIKE expression returns true if the string matches the supplied pattern. The MySQL implementation of the LIKE operator allows numeric expressions to be used.9.7.1. You can also use the ESCAPE clause to specify your own custom escape character. The input string didn’t have an underscore character in that spot and so the result was negative. The escaped version explicitly stated that only the underscore character ( _) will match. The unescaped version returned positive, because the wildcard meant that we could have any character in that spot. Let’s change the input string slightly so that we get a different result: SELECT The second line also matched, but only because the input string happened to have an underscore in the right place. ![]() The first line matched because the wildcard specified that any character will match. In this case, they both matched, but for different reasons. Here’s an example of such a search with and without the escape character: SELECT What happens if one of the wildcard characters are in your input string and you need to perform a match against it? You can escape it with the backslash character ( \). Here’s the full list of artists in that table:Įxample 4 – Escaping with the Backslash Character In this case, it was a simple query that returns all artists whose names start with the letter B. Here’s an example of how we can use this operator within a database query: When it’s used in this fashion, it narrows down the results to only those records that match, but we see the actual results (not just a 1 or 0). The LIKE operator is often used within a WHERE clause of a SELECT statement when querying a database. 'Charlie likes donuts' LIKE '_ likes _' AS 'Result 4' 'Charlie likes donuts' LIKE 'Charlie _likes donuts' AS 'Result 3', 'Charlie likes donuts' LIKE 'Charlie_nuts' AS 'Result 2', ![]() 'Charlie likes donuts' LIKE 'Ch%rlie_donuts' AS 'Result 1', Let’s make some changes to that example so that we can see some examples of when they don’t match: SELECT | Result 1 | Result 2 | Result 3 | Result 4 | 'Charlie likes donuts' LIKE '% likes %' AS 'Result 4' 'Charlie likes donuts' LIKE 'Ch%rlie %likes %' AS 'Result 3', 'Charlie likes donuts' LIKE 'Ch_rlie%nuts' AS 'Result 2', 'Charlie likes donuts' LIKE 'Ch_rlie%donuts' AS 'Result 1', The two wildcard characters can be combined within a pattern if required: SELECT 'Charlie likes donuts' LIKE 'Ch_rlie%' AS 'Result' ![]() Here’s an example: SELECT 'Charlie' LIKE 'Ch_rlie' We also have the option of using the _ wildcard character to specify only a single character. This is because we didn’t use a wildcard character to specify any other characters. The return result is 0 which means no match. Here’s what happens if we drop the %: SELECT 'Charlie' LIKE 'Char' ![]() The % character matches any number of characters (including zero characters). In particular, we specified that the input string should start with Char and end with anything. In this case, the return value is 1 which means that the input string matched the pattern. Here’s an example of how to use this operator in a SELECT statement: SELECT 'Charlie' LIKE 'Char%' The default escape character is \, so you can omit this clause if you don’t need to change this. The optional ESCAPE clause allows you to specify an escape character. Where expr is the input string and pat is the pattern for which you’re testing the string against. The syntax goes like this: expr LIKE pat This function can be used with string expressions and table columns. The pattern doesn’t necessarily need to be a literal string. If the string matches the pattern provided, the result is 1, otherwise it’s 0. In MySQL, the LIKE operator performs pattern matching using an SQL pattern.
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