How to compare strings in sql ignoring case? - sql

How do I write a query in Oracle ignoring the case of the strings being compared? For example "angel", "Angel", "ANGEL", "angel", "AngEl" would all be equal when compared.

If you are matching the full value of the field use
WHERE UPPER(fieldName) = 'ANGEL'
EDIT: From your comment you want to use:
SELECT
RPAD(a.name, 10,'=') "Nombre del Cliente"
, RPAD(b.name, 12,'*') "Nombre del Consumidor"
FROM
s_customer a,
s_region b
WHERE
a.region_id = b.id
AND UPPER(a.name) LIKE '%SPORT%'

You could use the UPPER keyword:
SELECT *
FROM Customers
WHERE UPPER(LastName) = UPPER('AnGel')

You can use:
select * from your_table where upper(your_column) like '%ANGEL%'
Otherwise, you can use:
select * from your_table where upper(your_column) = 'ANGEL'
Which will be more efficient if you are looking for a match with no additional characters before or after your_column field as Gary Ray suggested in his comments.

before comparing the two or more strings first execute the following commands
alter session set NLS_COMP=LINGUISTIC;
alter session set NLS_SORT=BINARY_CI;
after those two statements executed then you may compare the strings and there will be case insensitive.for example you had two strings s1='Apple' and s2='apple', if yow want to compare the two strings before executing the above statements then those two strings will be treated as two different strings but when you compare the strings after the execution of the two alter statements then those two strings s1 and s2 will be treated as the same string
reasons for using those two statements
We need to set NLS_COMP=LINGUISTIC and NLS_SORT=BINARY_CI in order to use 10gR2 case insensitivity. Since these are session modifiable, it is not as simple as setting them in the initialization parameters. We can set them in the initialization parameters but they then only affect the server and not the client side.

More detail on Mr Dredel's answer and tuinstoel's comment.
The data in the column will be stored in its specific case, but you can change your session's case-sensitivity for matching.
You can change either the session or the database to use linguistic or case insensitive searching. You can also set up indexes to use particular sort orders.
eg
ALTER SESSION SET NLS_SORT=BINARY_CI;
Once you start getting into non-english languages, with accents and so on, there's additional support for accent-insensitive.
Some of the capabilities vary by version, so check out the Globablization document for your particular version of Oracle. The latest (11g) is here

SELECT STRCMP("string1", "string2");
this returns 0 if the strings are equal.
If string1 = string2, this function returns 0 (ignoring the case)
If string1 < string2, this function returns -1
If string1 > string2, this function returns 1
https://www.w3schools.com/sql/func_mysql_strcmp.asp

To avoid string conversions comparisons, use COLLATE SQL_Latin1_General_CP1_CI_AS.
EXAMPLE:
SELECT UserName FROM Users
WHERE UserName COLLATE SQL_Latin1_General_CP1_CI_AS = 'Angel'
That will return any usernames, whether ANGEL, angel, or Angel, etc.

I don't recall the exact syntax, but you may set the table column to be case insensitive. But be careful because then you won't be able to match based on case anymore and if you WANT 'cool' to not match 'CoOl' it will no longer be possible.

Related

How to replace sql field case-sensitive value

I have one case-sensitive column.
How can I replace (Shpersonel,shPersonel, sHperSonel) to ShPersonel in all records?
my column Data is:
1- SHpersonel = 12 And Password= Ayuy122
2- ShpeRsonel = 10 And Password= jkjIUD122
3- ShPersonel = 08 And Password= Kjjam
...
You could use LOWER (or UPPER), which lots of DBMSes support, to look for a value case insensitively and update:
update your_table
set col = 'ShPersonel'
where lower(col) = 'shpersonel';
EDIT:
Further clarification explained that above data is stored in a single column - Which is not how it should be stored.
You should store the data in separate columns and then look for further normalization to remove unwanted dependencies.
UPDATE your_table
SET your_column = 'ShPersonel'
WHERE upper(your_column) = 'SHPERSONEL';
You didn't say what DBMS you're using. If it's SQL-Server, the following should work for you:
update MyTable
set TheData =
concat(
left(TheData,charindex('shpersonel',lower(t.TheData))-1),
'ShPersonel',
right(t.TheData,len(t.TheData) - charindex('shpersonel',lower(t.TheData)) - len('ShPersonel'))
)
from MyTable t
where
charindex('shpersonel',lower(t.TheData))>0
For other DBMS's you need to replace charindex with whatever that DBMS's equivalent may be. For example, Oracle and MySQL use InStr (which needs its arguments in the reverse order).

How do I get around case sensitive fields when in SQL

My code is:
CURSOR get_party_description is
select party_name
from ifsapp.IDENTITY_PAY_INFO_ALL
where party_type = :NEW.PARTY_TYPE
and identity = identity_
:NEW_PARTY_TYPE = 'SUPPLIER' while the value in the field is 'Supplier'. This code will pull back no records but if I change it to 'Supplier', it finds the record
How do I change to search with out matching the case?
You can convert both the variable and the field to upper or lower case.
where UPPER(party_type) = UPPER(:NEW.PARTY_TYPE)
This might cause a table space scan as the index on the field would be Case sensitive.
you can get around this by adding a generated column that is upper case and indexing that.
Change both of your values to upper case. Example:
CURSOR get_party_description is
select party_name
from ifsapp.IDENTITY_PAY_INFO_ALL
where UPPER(party_type) = UPPER('SUPPLIER')
and identity = identity_
Besides converting both strings to the same case (upper- or lower-) and then comparing them for equality, most SQL dialects allow one to do a case-insensitive comparison by using the LIKE operator, as follows:
CURSOR get_party_description is
select party_name
from ifsapp.IDENTITY_PAY_INFO_ALL
where party_type LIKE :NEW.PARTY_TYPE
and identity = identity_

How to update text using "regular expressions" in SQL Server?

In a column in a SQL Server database table, the value has a format of X=****;Y=****;Z=5****, where the asterisks represent strings of any lengths and of any values. What I need to do is to change that 5 to a 4 and keep the rest of the string unchanged.
Is there a way to use something like regular expressions to achieve what I want to do? If not using regular expressions, can it be done at all?
MS SQL sadly doesn't have any built in regex support (although it can be added via CLR) but if the format is fixed so that the part you want to change isZ=5toZ=4then usingREPLACEshould work:
REPLACE(your_string,'Z=5','Z=4')
For example:
declare #t table (str varchar(max))
insert #t values
('X=****;Y=****;Z=5****'),
('X=****;Y=**df**;Z=3**sdf**'),
('X=11**;Y=**sdfdf**;Z=5**')
update #t
set str = replace(str,'Z=5','Z=4')
-- or a slightly more ANSI compliant and portable way
update #t
set str = SUBSTRING(str,0, CHARINDEX('Z=5', str)) + 'Z=4' + SUBSTRING(str, CHARINDEX('Z=5', str)+3,LEN(str))
select * from #t
str:
X=****;Y=****;Z=4****
X=****;Y=**df**;Z=3**sdf**
X=11**;Y=**sdfdf**;Z=4**
We need more information. Under what circumstances should 5 be replaced by 4? If it's just where it occurs as the first character after the Z=, then you could simply do...
set Col = Replace(Col,'Z=5','Z=4')
Or, do you just want to replace 5 with 4 anywhere in the column value. In which case you'd obviously just do...
set Col = Replace(Col,'5','4')
Or possibly you mean that 5's should be replaced by 4's anywhere within the value after Z= which would be a lot harder.
update Table set Field = replace(Field, ';Z=5', ';Z=4')
And let's hope that your asterisked data doesn't contain semicolons and equality signs...

Regular expressions inside SQL Server

I have stored values in my database that look like 5XXXXXX, where X can be any digit. In other words, I need to match incoming SQL query strings like 5349878.
Does anyone have an idea how to do it?
I have different cases like XXXX7XX for example, so it has to be generic. I don't care about representing the pattern in a different way inside the SQL Server.
I'm working with c# in .NET.
You can write queries like this in SQL Server:
--each [0-9] matches a single digit, this would match 5xx
SELECT * FROM YourTable WHERE SomeField LIKE '5[0-9][0-9]'
stored value in DB is: 5XXXXXX [where x can be any digit]
You don't mention data types - if numeric, you'll likely have to use CAST/CONVERT to change the data type to [n]varchar.
Use:
WHERE CHARINDEX(column, '5') = 1
AND CHARINDEX(column, '.') = 0 --to stop decimals if needed
AND ISNUMERIC(column) = 1
References:
CHARINDEX
ISNUMERIC
i have also different cases like XXXX7XX for example, so it has to be generic.
Use:
WHERE PATINDEX('%7%', column) = 5
AND CHARINDEX(column, '.') = 0 --to stop decimals if needed
AND ISNUMERIC(column) = 1
References:
PATINDEX
Regex Support
SQL Server 2000+ supports regex, but the catch is you have to create the UDF function in CLR before you have the ability. There are numerous articles providing example code if you google them. Once you have that in place, you can use:
5\d{6} for your first example
\d{4}7\d{2} for your second example
For more info on regular expressions, I highly recommend this website.
Try this
select * from mytable
where p1 not like '%[^0-9]%' and substring(p1,1,1)='5'
Of course, you'll need to adjust the substring value, but the rest should work...
In order to match a digit, you can use [0-9].
So you could use 5[0-9][0-9][0-9][0-9][0-9][0-9] and [0-9][0-9][0-9][0-9]7[0-9][0-9][0-9]. I do this a lot for zip codes.
SQL Wildcards are enough for this purpose. Follow this link: http://www.w3schools.com/SQL/sql_wildcards.asp
you need to use a query like this:
select * from mytable where msisdn like '%7%'
or
select * from mytable where msisdn like '56655%'

What is the best way to select string fields based on character ranges?

I need to add the ability for users of my software to select records by character ranges.
How can I write a query that returns all widgets from a table whose name falls in the range Ba-Bi for example?
Currently I'm using greater than and less than operators, so the above example would become:
select * from widget
where name >= 'ba' and name < 'bj'
Notice how I have "incremented" the last character of the upper bound from i to j so that "bike" would not be left out.
Is there a generic way to find the next character after a given character based on the field's collation or would it be safer to create a second condition?
select * from widget
where name >= 'ba'
and (name < 'bi' or name like 'bi%')
My application needs to support localization. How sensitive is this kind of query to different character sets?
I also need to support both MSSQL and Oracle. What are my options for ensuring that character casing is ignored no matter what language appears in the data?
Let's skip directly to localization. Would you say "aa" >= "ba" ? Probably not, but that is where it sorts in Sweden. Also, you simply can't assume that you can ignore casing in any language. Casing is explicitly language-dependent, with the most common example being Turkish: uppercase i is İ. Lowercase I is ı.
Now, your SQL DB defines the result of <, == etc by a "collation order". This is definitely language specific. So, you should explicitly control this, for every query. A Turkish collation order will put those i's where they belong (in Turkish). You can't rely on the default collation.
As for the "increment part", don't bother. Stick to >= and <=.
For MSSQL see this thread: http://bytes.com/forum/thread483570.html .
For Oracle, it depends on your Oracle version, as Oracle 10 now supports regex(p) like queries: http://www.psoug.org/reference/regexp.html (search for regexp_like ) and see this article: http://www.oracle.com/technology/oramag/webcolumns/2003/techarticles/rischert_regexp_pt1.html
HTH
Frustratingly, the Oracle substring function is SUBSTR(), whilst it SQL-Server it's SUBSTRING().
You could write a simple wrapper around one or both of them so that they share the same function name + prototype.
Then you can just use
MY_SUBSTRING(name, 2) >= 'ba' AND MY_SUBSTRING(name, 2) <= 'bi'
or similar.
You could use this...
select * from widget
where name Like 'b[a-i]%'
This will match any row where the name starts with b, the second character is in the range a to i, and any other characters follow.
I think that I'd go with something simple like appending a high-sorting string to the end of the upper bound. Something like:
select * from widgetwhere name >= 'ba' and name <= 'bi'||'~'
I'm not sure that would survive EBCDIC conversion though
You could also do it like this:
select * from widget
where left(name, 2) between 'ba' and 'bi'
If your criteria length changes (as you seemed to indicate in a comment you left), the query would need to have the length as an input also:
declare #CriteriaLength int
set #CriteriaLength = 4
select * from widget
where left(name, #CriteriaLength) between 'baaa' and 'bike'