functions – Page 117

How the CHARACTER_LENGTH() Function Works in MySQL

November 19, 2019April 25, 2019 by Ian

In MySQL, the CHARACTER_LENGTH() function returns the length of a string, measured in characters.

CHARACTER_LENGTH() is a synonym for the CHAR_LENGTH() function.

How the SOUNDS LIKE Operator Works in MySQL

February 14, 2020April 24, 2019 by Ian

In MySQL, you can use the SOUNDS LIKE operator to return results that sound like a given word.

This operator works best on strings in the English language (using it with other languages may return unreliable results).

How the REGEX_REPLACE() Function Works in MySQL

April 29, 2021April 22, 2019 by Ian

In MySQL, the REGEXP_REPLACE() function replaces occurrences of the substring within a string that matches the given regular expression pattern.

The whole string is returned along with the replacements.

If there’s no match (i.e. the input string doesn’t contain the substring), the the whole string is returned unchanged.

How the REGEXP_INSTR() Function Works in MySQL

November 19, 2019April 22, 2019 by Ian

In MySQL, the REGEXP_INSTR() function returns the starting index of a substring that matches the regular expression pattern.

The index starts at 1. If there’s no match, the result is 0.

How the REGEXP_SUBSTR() Function Works in MySQL

November 19, 2019April 22, 2019 by Ian

In MySQL, the REGEXP_SUBSTR() function returns the substring that matches the given regular expression pattern.

If there’s no match (i.e. the input string doesn’t contain the substring), the result is NULL.

How NOT RLIKE Works in MySQL

November 19, 2019April 19, 2019 by Ian

In MySQL, NOT RLIKE is a negation of the RLIKE operator.

In other words, any time the RLIKE operator would return 1, NOT RLIKE will return 0.

How the RLIKE Operator Works in MySQL

February 14, 2020April 18, 2019 by Ian

In MySQL, the RLIKE operator is used to determine whether or not a string matches a regular expression. It’s a synonym for REGEXP_LIKE().

If the string matches the regular expression provided, the result is 1, otherwise it’s 0.

MySQL REGEXP Examples

November 19, 2019April 15, 2019 by Ian

In MySQL, the REGEXP operator is used to determine whether or not a string matches a regular expression. It’s a synonym for REGEXP_LIKE().

If the string matches the regular expression provided, the result is 1, otherwise it’s 0.

How the REGEXP_LIKE() Function Works in MySQL

November 19, 2019April 11, 2019 by Ian

In MySQL, the REGEXP_LIKE() function is used to determine whether or not a string matches a regular expression.

The function returns 1 if the string matches the regular expression provided, and 0 if it doesn’t.

How the WEIGHT_STRING() Function Works in MySQL

November 19, 2019April 10, 2019 by Ian

In MySQL, the WEIGHT_STRING() function returns the weight string for the input string. The return value is a binary string that represents the comparison and sorting value of the string.

If the input string is a nonbinary value, the return value contains the collation weights for the string. If it’s a binary value, the result is the same as the input string. This is because the weight for each byte in a binary string is the byte value.

This function is a debugging function intended for internal use. It can be used for testing and debugging of collations. Note that its behavior can change between MySQL versions.