I have a column STR which may contain any strings. I'm using MySql. How to find strings which don't contain letters in SQL without using Regular Expressions? As I understand RegExp in SQL is [^...].
So how to select the strings without using [^...]?
Regexp is the most sensible way of doing this. An alternative without...
SELECT STR
FROM YourTable
WHERE NOT EXISTS (SELECT *
FROM (SELECT 'A' AS C
UNION ALL
SELECT 'B'
UNION ALL
SELECT 'C'
/* Todo. Add remaining letters */
) Chars
WHERE INSTR(STR, C) > 0)
I am not sure which RDBMS you're using. But, if you do not want to use regular expression, you can loop through every character in the string and check the ASCII code. If they are only falling in the range 48 to 57, they are only numbers.
Note : This may be very costly operation
Related
I am trying to pull a product code from a long set of string formatted like a URL address. The pattern is always 3 letters followed by 3 or 4 numbers (ex. ???### or ???####). I have tried using REGEXP and LIKE syntax, but my results are off for both/I am not sure which operators to use.
The first select statement is close to trimming the URL to show just the code, but oftentimes will show a random string of numbers it may find in the URL string.
The second select statement is more rudimentary, but I am unsure which operators to use.
Which would be the quickest solution?
SELECT columnName, SUBSTR(columnName, LOCATE(columnName REGEXP "[^=\-][a-zA-Z]{3}[\d]{3,4}", columnName), LENGTH(columnName) - LOCATE(columnName REGEXP "[^=\-][a-zA-Z]{3}[\d]{3,4}", REVERSE(columnName))) AS extractedData FROM tableName
SELECT columnName FROM tableName WHERE columnName LIKE '%___###%' OR columnName LIKE '%___####%'
-- Will take a substring of this result as well
Example Data:
randomwebsite.com/3982356923abcd1ab?random_code=12480712_ABC_DEF_ANOTHER_CODE-xyz123&hello_world=us&etc_etc
In this case, the desired string is "xyz123" and the location of said pattern is variable based on each entry.
EDIT
SELECT column, LOCATE(column REGEXP "([a-zA-Z]{3}[0-9]{3,4}$)", column), SUBSTR(column, LOCATE(column REGEXP "([a-zA-Z]{3}[0-9]{3,4}$)", column), LENGTH(column) - LOCATE(column REGEXP "^.*[a-zA-Z]{3}[0-9]{3,4}", REVERSE(column))) AS extractData From mainTable
This expression is still not grabbing the right data, but I feel like it may get me closer.
I suggest using
REGEXP_SUBSTR(column, '(?<=[&?]random_code=[^&#]{0,256}-)[a-zA-Z]{3}[0-9]{3,4}(?![^&#])')
Details:
(?<=[&?]random_code=[^&#]{0,256}-) - immediately on the left, there must be & or &, random_code=, and then zero to 256 chars other than & and # followed with a - char
[a-zA-Z]{3} - three ASCII letters
[0-9]{3,4} - three to four ASCII digits
(?![^&#]) - that are followed either with &, # or end of string.
See the online demo:
WITH cte AS ( SELECT 'randomwebsite.com/3982356923abcd1ab?random_code=12480712_ABC_DEF_ANOTHER_CODE-xyz123&hello_world=us&etc_etc' val
UNION ALL
SELECT 'randomwebsite.com/3982356923abcd1ab?random_code=12480712_ABC_DEF_ANOTHER_CODE-xyz4567&hello_world=us&etc_etc'
UNION ALL
SELECT 'randomwebsite.com/3982356923abcd1ab?random_code=12480712_ABC_DEF_ANOTHER_CODE-xyz89&hello_world=us&etc_etc'
UNION ALL
SELECT 'randomwebsite.com/3982356923abcd1ab?random_code=12480712_ABC_DEF_ANOTHER_CODE-xyz00000&hello_world=us&etc_etc'
UNION ALL
SELECT 'randomwebsite.com/3982356923abcd1ab?random_code=12480712_ABC_DEF_ANOTHER_CODE-aaaaa11111&hello_world=us&etc_etc')
SELECT REGEXP_SUBSTR(val,'(?<=[&?]random_code=[^&#]{0,256}-)[a-zA-Z]{3}[0-9]{3,4}(?![^&#])') output
FROM cte
Output:
I'd make use of capture groups:
(?<=[=\-\\])([a-zA-Z]{3}[\d]{3,4})(?=[&])
I assume with [^=\-] you wanted to capture string with "-","\" or "=" in front but not include those chars in the result. To do that use "positive lookbehind" (?<=.
I also added a lookahead (?= for "&".
If you'd like to fidget more with regex I recommend RegExr
I'm trying to select all rows that contain only alphanumeric characters in MySQL using:
SELECT * FROM table WHERE column REGEXP '[A-Za-z0-9]';
However, it's returning all rows, regardless of the fact that they contain non-alphanumeric characters.
Try this code:
SELECT * FROM table WHERE column REGEXP '^[A-Za-z0-9]+$'
This makes sure that all characters match.
Your statement matches any string that contains a letter or digit anywhere, even if it contains other non-alphanumeric characters. Try this:
SELECT * FROM table WHERE column REGEXP '^[A-Za-z0-9]+$';
^ and $ require the entire string to match rather than just any portion of it, and + looks for 1 or more alphanumberic characters.
You could also use a named character class if you prefer:
SELECT * FROM table WHERE column REGEXP '^[[:alnum:]]+$';
Try this:
REGEXP '^[a-z0-9]+$'
As regexp is not case sensitive except for binary fields.
There is also this:
select m from table where not regexp_like(m, '^[0-9]\d+$')
which selects the rows that contains characters from the column you want (which is m in the example but you can change).
Most of the combinations don't work properly in Oracle platforms but this does. Sharing for future reference.
Try this
select count(*) from table where cast(col as double) is null;
Change the REGEXP to Like
SELECT * FROM table_name WHERE column_name like '%[^a-zA-Z0-9]%'
this one works fine
How do I remove all superfluous full-stop . and semi-colon ; characters from end of last name field values in SQL?
One way to check of the last character is a "full stop" or "semicolon" is to use a substring function to get the last character, and compare that to the characters you are looking for. (There are several ways to do this, for example, using LIKE or REGEXP operator.
If that last character matches, then lop off that last character. One way to do that is to use a substring function. (Use the CHAR_LENGTH function to return the number of characters in the string.)
For example, something like this:
UPDATE mytable t
SET t.last_name = SUBSTR(t.last_name,1,CHAR_LENGTH(t.last_name)-1)
WHERE SUBSTRING(t.last_name,CHAR_LENGTH(t.last_name),1) IN ('.',';')
But, I'd strongly recommend that you test those expressions using a SELECT statement, before running an UPDATE statement.
SELECT t.last_name AS old_val
, SUBSTR(t.last_name,1,CHAR_LENGTH(t.last_name)-1) AS new_val
FROM mytable t
WHERE SUBSTRING(t.last_name,CHAR_LENGTH(t.last_name),1) IN ('.',';')
Substring rows that have a semi-colon or dot :
update emp
set ename = substring(ename, 1, char_length(ename) - 1)
where ename REGEXP '[.;]$';
How can I select rows in MySQL that are not numbers?
SELECT *
FROM `TABLE`
WHERE `Column_B` <> Number
I know, this is a stupid question, but I haven't found a solution for this. Column_B is varchar(3).
Try this sqlfiddle..
http://sqlfiddle.com/#!2/17f28/1
SELECT * FROM Table1 WHERE col NOT REGEXP '^[0-9]+$'
If you want to match real numbers (floats) rather than integers, you need to handle the case above, along with cases where your pattern is between 0 and 1 (i.e. 0.25), as well as case where your pattern has a decimal part that is 0. (i.e. 2.0). And while we're at it, we'll add support for leading zeros on integers (i.e. 005):
^0*[1-9][0-9]*(\.[0-9]+)?|0+\.[0-9]*[1-9][0-9]*$
sql looks like SELECT * FROM Table1 WHERE col NOT REGEXP '^0*[1-9][0-9]*(\.[0-9]+)?|0+\.[0-9]*[1-9][0-9]*$'
This is one way of doing that, using mysql regexp operator (fiddle):
SELECT * FROM `TABLE`
WHERE `Column_B` NOT REGEXP '^-?[0-9]*\\.?[0-9]+([Ee][+-][0-9]+)?$';
Supports signed/unsigned integers, decimals, and scientific notation.
Note: it is recommended to avoid using sql keywords for entity names, even if you quote them with backticks.
this also will work for you
SELECT col FROM Table1
WHERE col NOT IN ( SELECT col FROM Table1
where CAST(col as DECIMAL(10,5)) !=0
or Col = '0' )
DEMO
SELECT * FROM t WHERE c REGEXP '.*\(..\).*';
This didn't work. It returned many rows whose c contain string that have more than two characters in ().
SELECT * FROM t WHERE c LIKE '%(__)%'
SQL Fiddle here
Your escapes are off.
http://dev.mysql.com/doc/refman/5.0/en/regexp.html#operator_regexp
Because MySQL uses the C escape syntax in strings (for example, “\n” to represent the newline character), you must double any “\” that you use in your REGEXP strings.
Use:
SELECT * FROM t WHERE c REGEXP '.*\\(..\\).*';
How are you running this query? If you're using it in (say) a PHP script, and writing it like this:
$sql = "SELECT ... REGEXP '.*\(..\).*';";
then the PHP interpreter will actually be stripping out those backslashes, producing the real query
... REGEXP '.*(..).*';
which would simply be any record that has at least two characters. For this to work properly, you'll have to double-escape:
$sql = "SELECT ... REGEXP '.*\\(..\\).*';";
PHP will strip off one of the backslashes from each set, leaving the second one to actually reach mysql.