What Does a Caret (^) Do in a SQL Query

What does a caret (^) do in a SQL query?

The caret (^) translates to the XOR operator, which is a "bitwise exclusive or". In plain english it means "either, but not both". Here's what it does:

decimal 1 = binary 001                     decimal 1 = binary 001
XOR                                        XOR
decimal 2 = binary 010                     decimal 3 = binary 011
=                                          =
decimal 3 = binary 011                     decimal 2 = binary 010

More info on the MSDN page for bitwise operations.

What is the difference to use CARET symbol in REGEXP_LIKE in oracle?

In this context, ^ represents the beginning of the string.

• '^[A-C]' checks for A, B or C at the beginning of the string.

• '[A-C]' checks for A, B or C at the anywhere in the string.

Depending on your dataset, both expressions might, or might not produce the same output. Here is on example where the resultset would be different:

last_name         | ^[A-C]   | [A-C] 
----------------- | -------  | ----- 
Arthur            | match    | match
Bill              | match    | match
Jean-Christophe   | no match | match

what does caret do in postgresql?

Your are looking for the use of the caret specifically within error messages.

If I run this query:

psql -c " Select * from cars where name ilike '%test'%'"

This is what I get, preserving line breaks and spaces:

ERROR:  unterminated quoted string at or near "'"
LINE 1:  Select * from cars where name ilike '%test'%'
                                                     ^

The caret points to where on the previous line the error occurred. In this case, that is where the opening quote mark that never got closed was located.

If you are using a tool which malformats your error messages, you should consider changing to one that does not or otherwise figuring out how to fix it.

What are the performance characteristics of caret or $ in a MySQL REGEXP?

No, there is no performance issue with using these. They are instead faster way of searching strings in comparison to nested queries. On HackerRank forum, I have seen many other course comments also where answers were right but people were just downvoting. Though the two lines in 'where city REGEXP' part can be combined and written in one line, the time complexity for both will be same. If you want to know more about Regex in MySQL, you can follow this post :-

https://www.geeksforgeeks.org/mysql-regular-expressions-regexp/

How can I escape a caret, tilde and curly braces in T-SQL?

Don't escape it.

As you already found out, if you want to find the caret, i.e. you are interested in it as a character, you have to escape it.

WHERE SampleString LIKE '%[\^]%' ESCAPE '\'

When you are trying to find strings that do not contain something, i.e. use the caret for its "function", you have to not escape it:

where SampleString LIKE '%[^~{}]%' ESCAPE '\' 

You could actually use both escaping and not escaping in the following example, where you would get strings that contains something else other than the caret:

where SampleString LIKE '%[^\^]%' ESCAPE '\'

What does caret(^) in Oracle translate function mean?

TRANSLATE(expr, from_string, to_string):

You cannot use an empty string for to_string to remove all characters
in from_string from the return value. Oracle Database interprets the
empty string as null, and if this function has a null argument, then
it returns null.

Thus you cannot specify '' as the value for the to_string parameter, because it would be interpreted as null.

I suspect ^ is used here because it will never appear in the expr, and thus you will never see it in the resulting string as in TRANSLATE('ABC12^3DE0F456', '^0123456789', '^') which returns ABC^DEF.

Your original function SELECT TRANSLATE('ABC123DEF456', '^0123456789', '^') FROM DUAL; effectively strips all digits from the source string because for every matching digit in from_string there's no corresponding character in to_string, the other characters are just ignored.

SQL Server LIKE caret (^) for NOT does not work as expected

'%[^m]%' would be true for any string containing a character that is not m. An expanded version would be '%[Any character not m]%'. Since all of those strings contain a character other than m, they are valid results.

If you had a string like mmm, where name like '%[^m]%' would not return that row.

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