how to compare string in SQL without using LIKE - sql

I am using SQL query shown below to compare AMCcode. But if I compare the AMCcode '1' using LIKE operator it will compare all the entries with AMCcode 1, 10,11,12,13. .. 19, 21,31.... etc. But I want to match the AMCcode only with 1. Please suggest how can I do it. The code is given below :
ISNULL(CONVERT(VARCHAR(10),PM.PA_AMCCode), '') like
(
CASE
WHEN #AMCCode IS NULL THEN '%'
ELSE '%'+#AMCCode+ '%'
END
)
This is part of the code where I need to replace the LIKE operator with any other operator which will give the AMCcode with 1 when I want to search AMCcode of 1, not all 10,11,12..... Please help

I think you are looking for something like this:
where ',' + cast(PM.PA_AMCCode as varchar(255)) + ',' like '%,' + #AMCCodes + ',%'
This includes the delimiters in the comparison.
Note that a better method is to split the string and use a join, something like this:
select t.*
from t cross apply
(select cast(code as int) as code
from dbo.split(#AMCCodes, ',') s(code)
) s
where t.AMCCode = s.code;
This is better because under some circumstances, this version can make use of an index on AMCCode.

If you want to exactly match the value, you don't need to use '%' in your query. You can just use like as below
ISNULL(CONVERT(VARCHAR(10),PM.PA_AMCCode), '') like
(
CASE
WHEN #AMCCode IS NULL THEN '%'
ELSE #AMCCode
END
)
Possibly you can remove case statement and query like
ISNULL(CONVERT(VARCHAR(10),PM.PA_AMCCode), '') like #AMCCode

Related

SQL Server check if value is substring inside isnull

I have a field in UI interface that passes to a stored procedure a null value (when field is unfilled) or a contract number when it is filled. Substrings of the contract number are accepted as input.
Inside the procedure, I need to filter the results by this parameter.
I need something similar to this:
SELECT * FROM tableName tn
WHERE
tn.ContractNumber LIKE ISNULL('%' + #contractNumber + '%', tn.ContractNumber)
What do you think it is the best approach? Problem is that using a condition like this does not return values.
Simply:
SELECT *
FROM tableName tn
WHERE tn.ContractNumber LIKE '%' + #contractNumber + '%'
OR #contractNumber IS NULL
You are really checking multiple condition, so having them separated reads more intuitive (for most people, anyway).
I assume this is just a sample query, and you are not selecting * in reality...
Another one:
SELECT *
FROM tableName tn
WHERE tn.ContractNumber LIKE '%' + ISNULL(#contractNumber, '%') + '%'

Like Query in SQL taking time

So I've looked around to try to find some posts on this and there are many
Like Query 1 and Like Query 2 but none that address my specific question (that I could find).
I have two tables in which I have around 5000000+ records and I am returning Search result from these tables as :
SELECT A.ContactFirstName, A.ContactLastName
FROM Customer.CustomerDetails AS A WITH (nolock)
WHERE (A.ContactFirstName + ' ' + A.ContactLastName LIKE '%' + 'a' + '%')
UNION
SELECT C.ContactFirstName, C.ContactLastName
FROM Customer.Contacts AS C WITH (nolock)
WHERE (C.ContactFirstName + ' ' + C.ContactLastName LIKE '%' + 'a' + '%')
My problem is it is taking around 1 minute to execute.
For above query I am expecting result like :
Please suggest me the best practice to improve performance. Thanks in advance.
NOTE : No missing Indexes.
when you use "LIKE '%xxx%'" index are not used that why your query is slow i think. When you use "LIKE 'xxx%')" index is used (if an index exist on column of course. >Other proble you do a like on concatenante column, i dont knwo if index is used in this case. And why do a 'xxx' + ' ' + 'yyy' like 'z%', just do 'xxx' like 'z%' its the same. You can try to modify your query like this
SELECT A.ContactFirstName, A.ContactLastName
FROM Customer.CustomerDetails AS A WITH (nolock)
WHERE A.ContactFirstName LIKE '%a%' or A.ContactLastName LIKE '%a%'
UNION
SELECT C.ContactFirstName, C.ContactLastName
FROM Customer.Contacts AS C WITH (nolock)
WHERE C.ContactFirstName LIKE 'a%'
Use Charindex which improves performance of the search ,Here it checks the string to match with first charcter of given search charecter and doesn't search for any more matches.
DECLARE #Search VARCHAR(10)='a'
SELECT A.ContactFirstName, A.ContactLastName
FROM Customer.CustomerDetails AS A WITH (NOLOCK)
WHERE CHARINDEX(#Search,(A.ContactFirstName + ' ' + A.ContactLastName),0)>1

Compare all possible substring of in two strings sql server 2008

I have a table with a column and value JobSkill = ".net sap lead". Now user enter the value "abap sap hana". I want to include a where condition which match exactly 3 or more continuous characters including space. In above scenario both have common "sap" substring so the condition should result in true. Below is my query. Please help. Previously I am using charindex but it does not resolve the purpose. I am using sql server 2008
SELECT Email_Id, JobSkill FROM Jobs
WHERE CHARINDEX(JobSkill, "abap sap hana") > 0
You need to create a function which loops through all positions of characters of String1 except the last 2, and check if String2 is like '%' + [(x,x+1,x+2)] + '%' string, where x is current position.
So for stings ('abcd acd g', 'ert acd'),
it should check
'ert acd' like '%abc%'
'ert acd' like '%bcd%'
'ert acd' like '%cd %'
'ert acd' like '%d a%'
and so on...
If like returns TRUE, break the loop.
Try like this,
SELECT j.Email_Id
,j.JobSkill
FROM Jobs j
INNER JOIN (
SELECT LTRIM(RTRIM(m.n.value('.[1]', 'varchar(8000)'))) SearchString
FROM (
SELECT CAST('<XMLRoot><RowData>' + REPLACE(#Input, ' ', '</RowData><RowData>') + '</RowData></XMLRoot>' AS XML) AS x
) t
CROSS APPLY x.nodes('/XMLRoot/RowData') m(n)
) T ON j.JobSkill LIKE '%' + T.SearchString + '%'

sql, using a subquery in the like operator

why does this work,
select*
from some_table
WHERE some_column_name like '%i%'
and not this?
select*
from some_table
WHERE
some_column_name like (select ''''+'%' +value +'%' + '''' as val
from [dbo].[fn_Split](' i this is a test testing Chinese undefined',' ')
where idx = 0)
I am trying to search for individual words instead of the whole phrase, the split function above will split the string on space characters and plug the results into a table with two columns, idx and value.
the LIKE operator takes a string for an argument. It cannot be used on a table, which I assume your function returns.
I think what you want to do is JOIN to the function, and then check where LIKE fn.Value:
select *
from some_table t
INNER JOIN (select value as val
from [dbo].[fn_Split](' i this is a test testing Chinese undefined',' ')
where idx = 0) f
ON t.some_column_name like '%'+f.val+'%'
If your subquery is guaranteed to only return one result, you could try putting the modulo symbols around it instead of inside it:
LIKE '%' + (YourSubQuery) + '%'
One possible reason is because you are appending single quotes onto the beginning and end of the string, and none of the values actually store single quotes in the string.
Another reason is might not work is because the subquery returns more than one row or zero rows. The function fn_split() is your own function, so I don't know what it returns. You have a subquery in a context where it can return at most one row and one column. That is called a scalar subquery. If the subquery returns more than one row, you will get an error. If the subquery returns no rows -- for instance, if idx starts counting at 1 rather than 0 -- then it will return NULL which fails the test.
If you want to find a match this way, I would recommend exists:
select t.*
from some_table t
where exists (select 1 as val
from [dbo].[fn_Split](' i this is a test testing Chinese undefined',' ') s
where s.idx = 0 and
t.some_column_name like '%' + value + '%'
);
The results of your sub-query is a literal string. The % symbol isn't seen as a wildcard. Also, does your functions return multiple rows? If so, LIKE operator can only evaluate a single value.
If your functions does return a single value, I would suggest looking into using Dynamic SQL. Something like the following:
DECLARE #SQL VARCHAR(MAX), #WildCard VARCHAR(MAX)
SELECT #WildCard = '%' + value + '%'
FROM [dbo].[fn_Split](' i this is a test testing Chinese undefined',' ')
WHERE idx = 0
SET #SQL = 'SELECT * FROM some_table WHERE some_column_name like ''' + #WildCardWildCard + ''''
EXEC(#SQL)

How to do an IN on a subquery with a CSV?

I have the following varchar value '1,2,4,5, ...' in a table column.
Basically, they're just codes in CSV format. I know it's a bad design, but that's what I have to deal with unfortunately.
Now I want to create a subquery to find descriptions that correspond to all codes.
How do I do that?
I've tried a subquery like
SELECT description FROM table WHERE table.CODE IN tablewithcsv.csvcolumn
But to no avail.
Normal IN's expect values like ('1', '2', '3'), but I suspect my value gets passed as '1,2,3'. Do I have to do some replacing here?
To search in a string, you can use:
SELECT description FROM `table`
INNER JOIN `tablewithcsv` ON `tablewithcsv`.csvcolumn LIKE '%' + `table`.CODE + '%'
This will work if the integers are only on character long, but will return false positives on more than one char. If you have more than one char, you can change it as such:
SELECT description FROM `table`
INNER JOIN `tablewithcsv` ON `tablewithcsv`.csvcolumn = `table`.CODE
OR `tablewithcsv`.csvcolumn LIKE `table`.CODE + ',%'
OR `tablewithcsv`.csvcolumn LIKE '%,' + `table`.CODE
OR `tablewithcsv`.csvcolumn LIKE '%,' + `table`.CODE + ',%'
This could also be done more elegantly using regular expressions