I am an absolute beginner in SQL.
Example:
I want to do a query to select people whose names begin with X if the result is 0, I want to select people whose names begin with Y.
How do I do this? Thanks.
I interpret the question as: show names starting with Y if no names starting with X are found.
This solution will be fast as it will short-cut the exists from the moment 1 record is found
if exists(select * from table where name like 'X%')
begin
select * from table where name like 'X%'
end
else
begin
select * from table where name like 'Y%'
end
Ideally the name column is indexed for this to work well.
May be this is a better solution:
select * from table where name like 'X%'
if ##ROWCOUNT = 0
select * from table where name like 'Y%'
There are ways to do perform this in a single SQL statement, but they are extremely expensive (both in time and resources). You would be best served to do this kind of logic in a stored procedure.
Here's a set-based solution:
SELECT *
FROM table
WHERE NAME LIKE 'X%'
UNION
SELECT *
FROM table
WHERE NAME LIKE 'Y%'
AND NOT EXISTS (
SELECT *
FROM table AS T1
WHERE T1.NAME LIKE 'X%'
);
Related
Following is the query to select column data from table, where column data starts with a OR b OR c. But the answer i am looking for is to Select data which starts with List of Strings.
SELECT * FROM Table WHERE Name LIKE '[abc]%'
But i want something like
SELECT * FROM Table WHERE Name LIKE '[ab,ac,ad,ae]%'
Can anybody suggest what is the best way of selecting column data which starts with list of String, I don't want to use OR operator, List of strings specifically.
The most general solution you would have to use is this:
SELECT *
FROM Table
WHERE Name LIKE 'ab%' OR Name LIKE 'ac%' OR Name LIKE 'ad%' OR Name LIKE 'ae%';
However, certain databases offer some regex support which you might be able to use. For example, in SQL Server you could write:
SELECT *
FROM Table
WHERE NAME LIKE 'a[bcde]%';
MySQL has a REGEXP operator which supports regex LIKE operations, and you could write:
SELECT *
FROM Table
WHERE NAME REGEXP '^a[bcde]';
Oracle and Postgres also have regex like support.
To add to Tim's answer, another approach could be to join your table with a sub-query of those values:
SELECT *
FROM mytable t
JOIN (SELECT 'ab' AS value
UNION ALL
SELECT 'ac'
UNION ALL
SELECT 'ad'
UNION ALL
SELECT 'ae') v ON t.vame LIKE v.value || '%'
I'm trying to write a SP that will allow users to search on multiple name strings, but supports LIKE functionality. For example, the user's input might be a string 'Scorsese, Kaurismaki, Tarkovsky'. I use a split function to turn that string into a table var, with one column, as follows:
part
------
Scorsese
Kaurismaki
Tarkovsky
Then, normally I would return any values from my table matching any of these values in my table var, with an IN statement:
select * from myTable where lastName IN (select * from #myTableVar)
However, this only returns exact matches, and I need to return partial matches. I'm looking for something like this, but that would actually compile:
select * from myTable where CONTAINS(lastName, select * from #myTableVar)
I've found other questions where it's made clear that you can't combine LIKE and IN, and it's recommended to use CONTAINS. My specific question is, is it possible to combine CONTAINS with a table list of values, as above? If so, what would that syntax look like? If not, any other workarounds to achieve my goal?
I'm using SQL Server 2016, if it makes any difference.
You can use EXISTS
SELECT * FROM myTable M
WHERE
EXISTS( SELECT * FROM #myTableVar V WHERE M.lastName like '%'+ V.part +'%' )
Can your parser built the entire statement? Will that get you what you want?
select *
from myTable
where CONTAINS
(lastName,
'"Scorsese" OR "Kaurismaki" OR "Tarkovsky"'
)
This can be done using CHARINDEX function combined with EXISTS:
select *
from myTable mt
where exists(select 1 from #myTableVar
where charindex(mt.lastName, part) > 0
or charindex(part, mt.lastName) > 0)
You might want to omit one of the conditions in the inner query, but I think this is what you want.
Just wanted to know if it was possible to do a pattern matching on a set of data from a table.
Like:
select * from Table where Column like any(select Pattern from PatternTable)
Note that the Pattern is always a substring of Column. Hence the use of like. Is it even possible to do this at a database level without the use of stored procedures?
If it helps, my RDBMS is MS SQL-Server
Edit:
Alright, I have a table containing a set of data like
PatternTable
____________
test1
test2
test3
test4
Now, a table Table has the following data:
Table
______
SomeDatatest4SomeData
SomeDataSomeData
Now, can I use a query as mentioned above to find a match: For the above query, this should return SomeDatatest4SomeData
You can do this using exists:
select *
from Table t
where exists (select 1
from PatternTable pt
where t.Column like pt.Pattern
);
SELECT t.*
FROM [Table] t
INNER JOIN PatternTable p ON t.[Column] LIKE '%' + p.Pattern + '%'
What is the most efficient and elegant SQL query looking for a string containing the words "David", "Moses" and "Robi". Assume the table is named T and the column C.
Select * from table where
columnname like'%David%' and
columnname like '%Moses%' and columnname like'%Robi%'
In SQL Server 2005+ with Full-Text indexing switched on, I'd do the following:
SELECT *
FROM T
WHERE CONTAINS(C, '"David" OR "Robi" OR "Moses"');
If you wanted your search to bring back results where the result is prefixed with David, Robi or Moses you could do:
SELECT *
FROM T
WHERE CONTAINS(C, '"David*" OR "Robi*" OR "Moses*"');
Here is what I uses to search for multiple words in multiple columns - SQL server
Hope my answer help someone :) Thanks
declare #searchTrm varchar(MAX)='one two three ddd 20 30 comment';
--select value from STRING_SPLIT(#searchTrm, ' ') where trim(value)<>''
select * from Bols
WHERE EXISTS (SELECT value
FROM STRING_SPLIT(#searchTrm, ' ')
WHERE
trim(value)<>''
and(
BolNumber like '%'+ value+'%'
or UserComment like '%'+ value+'%'
or RequesterId like '%'+ value+'%' )
)
If you care about the sequence of the terms, you may consider using a syntax like
select * from T where C like'%David%Moses%Robi%'
Oracle SQL :
select *
from MY_TABLE
where REGEXP_LIKE (company , 'Microsodt industry | goglge auto car | oracles database')
company - is the database column name.
results - this SQL will show you if company column rows contain one of those companies (OR phrase)
please note that : no wild characters are needed, it's built in.
more info at : http://www.techonthenet.com/oracle/regexp_like.php
if you put all the searched words in a temporaray table say #tmp and column col1, then you could try this:
Select * from T where C like (Select '%'+col1+'%' from #temp);
Maybe EXISTS can help.
and exists (select 1 from #DocumentNames where pcd.Name like DocName+'%' or CD.DocumentName like DocName+'%')
Oracle SQL:
There is the "IN" Operator in Oracle SQL which can be used for that:
select
namet.customerfirstname, addrt.city, addrt.postalcode
from schemax.nametable namet
join schemax.addresstable addrt on addrt.adtid = namet.natadtid
where namet.customerfirstname in ('David', 'Moses', 'Robi');
I am trying to find a way, if possible, to use IN and LIKE together. What I want to accomplish is putting a subquery that pulls up a list of data into an IN statement. The problem is the list of data contains wildcards. Is there any way to do this?
Just something I was curious on.
Example of data in the 2 tables
Parent table
ID Office_Code Employee_Name
1 GG234 Tom
2 GG654 Bill
3 PQ123 Chris
Second table
ID Code_Wildcard
1 GG%
2 PQ%
Clarifying note (via third-party)
Since I'm seeing several responses which don't seems to address what Ziltoid asks, I thought I try clarifying what I think he means.
In SQL, "WHERE col IN (1,2,3)" is roughly the equivalent of "WHERE col = 1 OR col = 2 OR col = 3".
He's looking for something which I'll pseudo-code as
WHERE col IN_LIKE ('A%', 'TH%E', '%C')
which would be roughly the equivalent of
WHERE col LIKE 'A%' OR col LIKE 'TH%E' OR col LIKE '%C'
The Regex answers seem to come closest; the rest seem way off the mark.
I'm not sure which database you're using, but with Oracle you could accomplish something equivalent by aliasing your subquery in the FROM clause rather than using it in an IN clause. Using your example:
select p.*
from
(select code_wildcard
from second
where id = 1) s
join parent p
on p.office_code like s.code_wildcard
In MySQL, use REGEXP:
WHERE field1 REGEXP('(value1)|(value2)|(value3)')
Same in Oracle:
WHERE REGEXP_LIKE(field1, '(value1)|(value2)|(value3)')
Do you mean somethign like:
select * FROM table where column IN (
SELECT column from table where column like '%%'
)
Really this should be written like:
SELECT * FROM table where column like '%%'
Using a sub select query is really beneficial when you have to pull records based on a set of logic that you won't want in the main query.
something like:
SELECT * FROM TableA WHERE TableA_IdColumn IN
(
SELECT TableA_IdColumn FROM TableB WHERE TableA_IDColumn like '%%'
)
update to question:
You can't combine an IN statement with a like statement:
You'll have to do three different like statements to search on the various wildcards.
You could use a LIKE statement to obtain a list of IDs and then use that in the IN statement.
But you can't directly combine IN and LIKE.
Perhaps something like this?
SELECT DISTINCT
my_column
FROM
My_Table T
INNER JOIN My_List_Of_Value V ON
T.my_column LIKE '%' + V.search_value + '%'
In this example I've used a table with the values for simplicity, but you could easily change that to a subquery. If you have a large list (like tens of thousands) then performance might be rough.
select *
from parent
where exists( select *
from second
where office_code like trim( code_wildcard ) );
Trim code_wildcard just in case it has trailing blanks.
You could do the Like part in a subquery perhaps?
Select * From TableA Where X in (Select A from TableB where B Like '%123%')
tsql has the contains statement for a full-text-search enabled table.
CONTAINS(Description, '"sea*" OR "bread*"')
If I'm reading the question correctly, we want all Parent rows that have an Office_code that matches any Code_Wildcard in the "Second" table.
In Oracle, at least, this query achieves that:
SELECT *
FROM parent, second
WHERE office_code LIKE code_wildcard;
Am I missing something?