Was working on SQL-EX.ru exercises.
There is one question for DML that I could not do, but I cannot proceed to the next one, until this one is done.
the question itself: All the trailing spaces in the name column of the Battles table remove and add them at the beginning of the name.
My code:
Update Battles
set name=concat(' ',(LTRIM(RTRIM(name))))
The system does not let it go through, I understand that I am using ' ' for the concat, whereas I need to use the stuff that got trimmed. And I have no idea how...
Any help would be very much appreciated
Try Something Like:-
set name = lpad(trim(name), length(trim(name))+4, ' ')
Here use TRIM to remove space from both side. use LPAD to add something on left side with n (4) chars
I'm not familiar with SQL-EX.ru, but if it's Oracle compatible and you can use regular expressions (or you are at that point in the training) here's a way. Maybe it'll give you an idea at least. The first part is just setup and uses a WITH clause to create a table (like a temp table in memory, actually called a Common Table Expression or CTE) called battles containing a name column with 2 rows. Each name column datum has a different number of spaces at the end. Next select from that column using a regular expression that uses 2 "remembered" groups surrounded by parentheses, the first containing the string up to until but not including the first space, the second containing 0 or more space characters anchored to the end of the line. Replace that with the 2nd group (the spaces) first, followed by the first group (the first part of the string). This is surrounded by square brackets just to prove in the output the same spaces were moved to the front of the string.
SQL> with battles(name) as (
select 'test2 ' from dual union
select 'test1 ' from dual
)
select '[' || regexp_replace(name, '(.*?)([ ]*)$', '\2\1') || ']' fixed
from battles;
FIXED
----------------------------------------------------------------------------
[ test1]
[ test2]
SQL>
I hope this solution can be applied to your problem or at least give you some ideas.
Try this:
set name = case when len(name) > len(rtrim(name))
then replicate(' ', len(name) - len(rtrim(name))) + rtrim(name)
else name
end
update battles
set name = case when (len(name+'a')-1) > len(rtrim(name))
then
replicate(' ',
(len(name+'a')-1) - len(rtrim(name))) + rtrim(name)
else name
end
Len() doesn't count trailing spaces. So using (len(name+'a')-1).
Simplest answer:
UPDATE Battles
SET name = SPACE(DATALENGTH(name)-DATALENGTH(RTRIM(name))) + RTRIM(name)
But only works because name is VARCHAR.
More generic is to do:
UPDATE Battles
SET name = SPACE(len(name+'x')-1-len(RTRIM(name))) + RTRIM(name)
simple example below ... enjoy :)
update battles set name =
Space( DATALENGTH(name) - DATALENGTH(rtrim(name))) + rtrim(name)
where date in ( select date from battles)
Related
I want to select where 2 strings but without taking
underscore
apostrophe
dash..
Hello !
I want to select an option in my SQL database who look like this :
Chef d'équipe aménagement-finitions
With an original tag who look like this
chef-déquipe-aménagement-finitions
Some results in database had a - too
SELECT *
FROM table
WHERE REPLACE(name, '-', ' ') = REPLACE('chef-déquipe-aménagement-finitions', '-', ' ')
didnt work because of missing '
And a double replace didn't work too.
I want the string be able to compare without taking
underscore
apostrophe
dash
and all things like that
is this possible ?
Thanks for your help
Have good day !
Depends on your rdbms, but here's how I would perform in MySQL 8. If using a different version or rdbms, then first determine how to escape the single quote and modify as needed.
with my_data as (
select 'Chef d''équipe aménagement-finitions' as name
)
select name,
lower(replace(replace(name, '\'', ''), ' ', '-')) as name2
from my_data;
name
name2
Chef d'équipe aménagement-finitions
chef-déquipe-aménagement-finitions
Sql-server and Postgres version:
lower(replace(replace(name, '''', ''), ' ', '-')) as name
After posting, this, I re-read and noticed you are also looking to replace other characters. You could either keep layering the replace function, or, look into other functions.
I have a column in a table ident_nums that contains different types of ids. I need to remove special characters(e.g. [.,/#&$-]) from that column and replace them with space; however, if the special characters are found at the beginning of the string, I need to remove it without placing a space. I tried to do it in steps; first, I removed the special characters and replaced them with space (I used
REGEXP_REPLACE) then found the records that contain spaces at the beginning of the string and tried to use the TRIM function to remove the white space, but for some reason is not working that.
Here is what I have done
Select regexp_replace(id_num, '[:(),./#*&-]', ' ') from ident_nums
This part works for me, I remove all the unwanted characters from the column, however, if the string in the column starts with a character I don't want to have space in there, I would like to remove just the character, so I tried to use the built-in function TRIM.
update ident_nums
set id_num = TRIM(id_num)
I'm getting an error ORA-01407: can't update ident_nums.id_num to NULL
Any ideas what I am doing wrong here?
It does work if I add a where clause,
update ident_nums
set id_num = TRIM(id_num) where id = 123;
but I need to update all the rows with the white space at the beginning of the string.
Any suggestions are welcome.
Or if it can be done better.
The table has millions of records.
Thank you
Regexp can be slow sometimes so if you can do it by using built-in functions - consider it.
As #Abra suggested TRIM and TRANSLATE is a good choice, but maybe you would prefer LTRIM - removes only leading spaces from string (TRIM removes both - leading and trailing character ). If you want to remove "space" you can ommit defining the trim character parameter, space is default.
select
ltrim(translate('#kdjdj:', '[:(),./#*&-]', ' '))
from dual;
select
ltrim(translate(orginal_string, 'special_characters_to_remove', ' '))
from dual;
Combination of Oracle built-in functions TRANSLATE and TRIM worked for me.
select trim(' ' from translate('#$one,$2-zero...', '#$,-.',' ')) as RESULT
from DUAL
Refer to this dbfiddle
I think trim() is the key, but if you want to keep only alpha numerics, digits, and spaces, then:
select trim(' ' from regexp_replace(col, '[^a-zA-Z0-9 ]', ' ', 1, 0))
regexp_replace() makes it possible to specify only the characters you want to keep, which could be convenient.
Thanks, everyone, It this query worked for me
update update ident_nums
set id_num = LTRIM(REGEXP_REPLACE(id_num, '[:space:]+', ' ')
where REGEXP_LIKE(id_num, '^[ ?]')
this should work for you.
SELECT id_num, length(id_num) length_old, NEW_ID_NUM, length(NEW_ID_NUM) len_NEW_ID_NUM, ltrim(NEW_ID_NUM), length(ltrim(NEW_ID_NUM)) length_after_ltrim
FROM (
SELECT id_num, regexp_replace(id_num, '[:(),./#*&-#]', ' ') NEW_ID_NUM FROM
(
SELECT '1234$%45' as id_num from dual UNION
SELECT '#SHARMA' as id_num from dual UNION
SELECT 'JACK TEST' as id_num from dual UNION
SELECT 'XYZ#$' as id_num from dual UNION
SELECT '#ABCDE()' as id_num from dual -- THe 1st character is space
)
)
I have a column in my SQL Server database and it has white spaces from left and right site of the record. Basically it's a nvarchar(250) column.
I have tried removing white spaces completely like this:
UPDATE MyTable
SET whitespacecolumn = LTRIM(RTRIM(whitespacecolumn))
But this didn't work out at all, the whitespace is still there. What am I doing wrong here?
Check the below;
Find any special characters like char(10), char(13) etc in the field value.
Check the status of ANSI_PADDING ON. Refer this MSDN article.
I think replace is the way as you are looking to update
UPDATE MyTable SET whitespacecolumn = Replace(whitespacecolumn, ' ', '')
you can try doing select first and then prefer to update
SELECT *, Replace(whitespacecolumn, ' ', '') from MyTable
LTRIM, RTRIM will remove spaces in front and rear of column. In 2016 you can use TRIM function as below to trim special characters as well:
SELECT TRIM( '.,! ' FROM '# test .') AS Result;
Output:
# test
I want to select names from a table where the 'name' column contains '%' anywhere in the value. For example, I want to retrieve the name 'Approval for 20 % discount for parts'.
SELECT NAME FROM TABLE WHERE NAME ... ?
You can use like with escape. The default is a backslash in some databases (but not in Oracle), so:
select name
from table
where name like '%\%%' ESCAPE '\'
This is standard, and works in most databases. The Oracle documentation is here.
Of course, you could also use instr():
where instr(name, '%') > 0
One way to do it is using replace with an empty string and checking to see if the difference in length of the original string and modified string is > 0.
select name
from table
where length(name) - length(replace(name,'%','')) > 0
Make life easy on yourselves and just use REGEXP_LIKE( )!
SQL> with tbl(name) as (
select 'ABC' from dual
union
select 'E%FS' from dual
)
select name
from tbl
where regexp_like(name, '%');
NAME
----
E%FS
SQL>
I read the documentation mentioned by Gordon. The relevent sentence is:
An underscore (_) in the pattern matches exactly one character (as opposed to one byte in a multibyte character set) in the value
Here was my test:
select c
from (
select 'a%be' c
from dual) d
where c like '_%'
The value a%be was returned.
While the suggestions of using instr() or length in the other two answers will lead to the correct answer, they will do so slowly. Filtering on function results simply take longer than filtering on fields.
Given data in a column which look like this:
00001 00
00026 00
I need to use SQL to remove anything after the space and all leading zeros from the values so that the final output will be:
1
26
How can I best do this?
Btw I'm using DB2
This was tested on DB2 for Linux/Unix/Windows and z/OS.
You can use the LOCATE() function in DB2 to find the character position of the first space in a string, and then send that to SUBSTR() as the end location (minus one) to get only the first number of the string. Casting to INT will get rid of the leading zeros, but if you need it in string form, you can CAST again to CHAR.
SELECT CAST(SUBSTR(col, 1, LOCATE(' ', col) - 1) AS INT)
FROM tab
In DB2 (Express-C 9.7.5) you can use the SQL standard TRIM() function:
db2 => CREATE TABLE tbl (vc VARCHAR(64))
DB20000I The SQL command completed successfully.
db2 => INSERT INTO tbl (vc) VALUES ('00001 00'), ('00026 00')
DB20000I The SQL command completed successfully.
db2 => SELECT TRIM(TRIM('0' FROM vc)) AS trimmed FROM tbl
TRIMMED
----------------------------------------------------------------
1
26
2 record(s) selected.
The inner TRIM() removes leading and trailing zero characters, while the outer trim removes spaces.
This worked for me on the AS400 DB2.
The "L" stands for Leading.
You can also use "T" for Trailing.
I am assuming the field type is currently VARCHAR, do you need to store things other than INTs?
If the field type was INT, they would be removed automatically.
Alternatively, to select the values:
SELECT (CAST(CAST Col1 AS int) AS varchar) AS Col1
I found this thread for some reason and find it odd that no one actually answered the question. It seems that the goal is to return a left adjusted field:
SELECT
TRIM(L '0' FROM SUBSTR(trim(col) || ' ',1,LOCATE(' ',trim(col) || ' ') - 1))
FROM tab
One option is implicit casting: SELECT SUBSTR(column, 1, 5) + 0 AS column_as_number ...
That assumes that the structure is nnnnn nn, ie exactly 5 characters, a space and two more characters.
Explicit casting, ie SUBSTR(column,1,5)::INT is also a possibility, but exact syntax depends on the RDBMS in question.
Use the following to achieve this when the space location is variable, or even when it's fixed and you want to make a more robust query (in case it moves later):
SELECT CAST(SUBSTR(LTRIM('00123 45'), 1, CASE WHEN LOCATE(' ', LTRIM('00123 45')) <= 1 THEN LEN('00123 45') ELSE LOCATE(' ', LTRIM('00123 45')) - 1 END) AS BIGINT)
If you know the column will always contain a blank space after the start:
SELECT CAST(LOCATE(LTRIM('00123 45'), 1, LOCATE(' ', LTRIM('00123 45')) - 1) AS BIGINT)
both of these result in:
123
so your query would
SELECT CAST(SUBSTR(LTRIM(myCol1), 1, CASE WHEN LOCATE(' ', LTRIM(myCol1)) <= 1 THEN LEN(myCol1) ELSE LOCATE(' ', LTRIM(myCol1)) - 1 END) AS BIGINT)
FROM myTable1
This removes any content after the first space character (ignoring leading spaces), and then converts the remainder to a 64bit integer which will then remove all leading zeroes.
If you want to keep all the numbers and just remove the leading zeroes and any spaces you can use:
SELECT CAST(REPLACE('00123 45', ' ', '') AS BIGINT)
While my answer might seem quite verbose compared to simply SELECT CAST(SUBSTR(myCol1, 1, 5) AS BIGINT) FROM myTable1 but it allows for the space character to not always be there, situations where the myCol1 value is not of the form nnnnn nn if the string is nn nn then the convert to int will fail.
Remember to be careful if you use the TRIM function to remove the leading zeroes, and actually in all situations you will need to test your code with data like 00120 00 and see if it returns 12 instead of the correct value of 120.