I have a string containing a certain number of words (it may vary from 1 to many) and I need to find the records of a table which contains ALL those words in any order.

For instances, suppose that my input string is 'yellow blue red' and I have a table with the following records:

1 yellow brown white
2 red blue yellow
3 black blue red

The query should return the record 2.

I know that the basic approach should be something similar to this:

select * from mytable where colors like '%yellow%' and colors like '%blue%' and colors like '%red%'

However I am not being able to figure out how turn the words of the string into separate like parameters.

I have this code that splits the words of the string into a table, but now I am stuck:

DECLARE @mystring varchar(max) = 'yellow blue red';
DECLARE @terms TABLE (term varchar(max));
INSERT INTO @terms
SELECT Split.a.value('.', 'NVARCHAR(MAX)') term FROM (SELECT CAST('<X>' REPLACE(@mystring, ' ', '</X><X>') '</X>' AS XML) AS String) AS A CROSS APPLY String.nodes('/X') AS Split(a)
SELECT * FROM @terms

Any idea?

CodePudding user response：

First, put that XML junk in a function:

CREATE FUNCTION dbo.SplitThem
(
   @List       NVARCHAR(MAX),
   @Delimiter  NVARCHAR(255)
)
RETURNS TABLE
WITH SCHEMABINDING
AS
   RETURN ( SELECT Item = y.i.value(N'(./text())[1]', N'nvarchar(4000)')
      FROM ( SELECT x = CONVERT(XML, '<i>' 
            REPLACE(@List, @Delimiter, '</i><i>') 
            '</i>').query('.')
      ) AS a CROSS APPLY x.nodes('i') AS y(i));

Now you can extract the words in the table, join them to the words in the input string, and discard any that don't have the same count:

DECLARE @mystring varchar(max) = 'red yellow blue';

;WITH src AS 
(
  SELECT t.id, t.colors, fc = f.c, tc = COUNT(t.id)
  FROM dbo.mytable AS t
  CROSS APPLY dbo.SplitThem(t.colors, ' ') AS s
  INNER JOIN (SELECT Item, c = COUNT(*) OVER()
    FROM dbo.SplitThem(@mystring, ' ')) AS f
  ON s.Item = f.Item
  GROUP BY t.id, t.colors, f.c
)
SELECT * FROM src
WHERE fc = tc;

Output:

• Example db<>fiddle

This disregards any possibility of duplicates on either side and ignores the larger overarching issue that this is the least optimal way possible to store sets of things. You have a relational database, use it! Surely you don't think the tags on this question are stored somewhere as the literal string

string sql-server-2012 sql-like

Of course not, these question:tag relationships are stored in a, well, relational table. Splitting strings is for the birds and those with all kinds of CPU and time to spare.

CodePudding user response：

If you are storing a delimited list in a single column then you really need to normalize it out into a separate table.

But assuming you actually want to just do multiple free-form LIKE comparisons, you can do them against a list of values:

select *
from mytable t
where not exists (select 1
    from (values
        ('%yellow%'),
        ('%blue%'),
        ('%red%')
    ) v(search)
    where t.colors not like v.search
);

Ideally you should pass these values through as a Table Valued Parameter, then you just put that into your query

select *
from mytable t
where not exists (select 1
    from @tmp v
    where t.colors not like v.search
);

If you want to simulate an OR semantic rather than AND the change not exists to exists and not like to like.