In MariaDB, 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
.
Syntax
The syntax goes like this:
expr NOT RLIKE pat
Where expr
is the input string and pat
is the regular expression for which you’re testing the string against.
It’s the equivalent of doing the following:
NOT (expr RLIKE pat)
Example
Here’s an example of using this in a SELECT
statement:
SELECT 'Coffee' NOT RLIKE '^C.*e$';
Result:
+-----------------------------+ | 'Coffee' NOT RLIKE '^C.*e$' | +-----------------------------+ | 0 | +-----------------------------+
Here, the pattern is matched if the input string starts with C
and ends with e
. It does, but because we use NOT RLIKE
, we get a negative result (0
).
The above statement is the equivalent of doing this:
SELECT NOT ('Coffee' RLIKE '^C.*e$');
Result:
+-------------------------------+ | NOT ('Coffee' RLIKE '^C.*e$') | +-------------------------------+ | 0 | +-------------------------------+
Compared to RLIKE
Here we compare the results from RLIKE
with NOT RLIKE
:
SELECT
'Coffee' RLIKE '^C.*e$' AS "RLIKE",
'Coffee' NOT RLIKE '^C.*e$' AS "NOT RLIKE";
Result:
+-------+-----------+ | RLIKE | NOT RLIKE | +-------+-----------+ | 1 | 0 | +-------+-----------+
A Positive Result
The previous examples resulted in 0
for NOT RLIKE
, because the string did actually match the pattern. Here’s an example where we get a 1
, which indicates that the string doesn’t match:
SELECT
'Funny' RLIKE '^C.*e$' AS "RLIKE",
'Funny' NOT RLIKE '^C.*e$' AS "NOT RLIKE";
Result:
+-------+-----------+ | RLIKE | NOT RLIKE | +-------+-----------+ | 0 | 1 | +-------+-----------+
Alternatives
MariaDB includes many functions and operators that essentially do the same thing, and this also applies to NOT RLIKE
.
RLIKE
is a synonym of theREGEXP
operator.NOT RLIKE
is the equivalent ofNOT REGEXP
.RLIKE
andREGEXP
can be negated by simply using theNOT
logical operator.
Therefore, all of the following are equivalent:
expr NOT RLIKE pat
expr NOT REGEXP pat
NOT (expr RLIKE pat)
NOT (expr REGEXP pat)
And here’s an example to demonstrate:
SELECT
'Car' NOT RLIKE '^C' AS "Result 1",
'Car' NOT REGEXP '^C' AS "Result 2",
NOT ('Car' RLIKE '^C') AS "Result 3",
NOT ('Car' REGEXP '^C') AS "Result 4";
Result:
+----------+----------+----------+----------+ | Result 1 | Result 2 | Result 3 | Result 4 | +----------+----------+----------+----------+ | 0 | 0 | 0 | 0 | +----------+----------+----------+----------+