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.
string functions
How the RLIKE Operator Works in MySQL
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
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 WEIGHT_STRING() Function Works in MySQL
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.
How the UNHEX() Function Works in MySQL
In MySQL, the UNHEX() function allows you to “unhex” a string in MySQL. In other words, it allows you to convert a hexadecimal value to a human-readable string.
Specifically, the function interprets each pair of characters in the argument as a hexadecimal number and converts it to the byte represented by the number. The return value is a binary string.
How the POSITION() Function Works in MySQL
In MySQL, the POSITION() function returns the position of the first occurrence of a substring within the string.
This function is actually a synonym for LOCATE(), but with a slightly different syntax. The LOCATE() function also has extra functionality, in that it allows you to define a starting position fro your search.