Just curious about the IN statement in SQL.
I know I can search multiple columns with one value by doing
'val1' IN (col1,col2)
And can search a column for multiple values
col1 IN ('val1','val2')
But is there a way to do both of these simultaneously, without restorting to an repeating AND / OR in the SQl? I am looking to do this in the most scalable way, so independent of how many vals / cols i need to search in.
So essentially:
('val1','val2') IN (col1,col2)
but valid.
You could do something like this (which I've also put on SQLFiddle):
-- Test data:
WITH t(col1, col2) AS (
SELECT 'val1', 'valX' UNION ALL
SELECT 'valY', 'valZ'
)
-- Solution:
SELECT *
FROM t
WHERE EXISTS (
SELECT 1
-- Join all columns with all values to see if any column matches any value
FROM (VALUES(t.col1),(t.col2)) t1(col)
JOIN (VALUES('val1'),('val2')) t2(val)
ON col = val
)
Of course, one could argue, which version is more concise.
Yes, for example you can do this in Oracle:
select x, y from (select 1 as x, 2 as y from dual)
where (x,y) in (select 1 as p, 2 as q from dual)
Related
I am using WinSQL to run a query on a table to count the number of occurrences of literal strings. When trying to do a count on a specific set of strings, I still want to see if some values return a count of 0. For example:
select letter, count(*)
from table
where letter in ('A', 'B', 'C')
group by letter
Let's say we know that 'A' occurs 3 times, 'B' occurs 0 times, and 'C' occurs 5 times. I expect to have a table returned as such:
letter count
A 3
B 0
C 5
However, the table never returns a row with a 0 count, which results like so:
letter count
A 3
C 5
I've looked around and saw some articles mentioning the use of joins, but I've had no luck in correctly returning a table that looks like the first example.
You can create an in-line table containing all letters that you look for, then LEFT JOIN your table to it:
select t1.col, count(t2.letter)
from (
select 'A' AS col union all select 'B' union all select 'C'
) as t1
left join table as t2 on t1.col = t2.letter
group by t1.col
on many platforms you can now use the values statement instead of union all to create your "in line" table - like this
select t.letter, count(mytable.letter)
from ( values ('A'),('B'),('C') ) as t(letter)
left join mytable on t.letter = mytable.letter
group by t.letter
I'm not that familiar with WinSQL, but it's not pretty if you don't have the values that you want in the left most column in a table somewhere. If you did, you could use a left join and a conditional. Without it, you can do something like this:
SELECT all_letters.letter, IFNULL(letter_count.letter_count, 0)
FROM
(
SELECT 'A' AS letter
UNION
SELECT 'B' AS letter
UNION
SELECT 'C' AS letter
) all_letters
LEFT JOIN
(SELECT letter, count(*) AS letter_count
FROM table
WHERE letter IN ('A', 'B', 'C')
GROUP BY letter) letter_count
ON all_letters.letter = letter_count.letter
Suppose I have a table of strings, like this:
VAL
-----------------
Content of values
Values identity
Triple combo
my combo
sub-zero combo
I want to find strings which have equal words. The result set should be like
VAL MATCHING_VAL
------------------ ------------------
Content of values Values identity
Triple combo My combo
Triple combo sub-zero combo
or at least something like this.
Can you help?
One method is to use a hack for regular expressions:
select t1.val, t2.val
from t t1 join
t t2
on regexp_like(t1.val, replace(t2.val, ' ', '|');
You might want the case to be identical as well:
on regexp_like(lower(t1.val), replace(lower(t2.val), ' ', '|');
You could use a combination of SUBSTRING and LIKE.
use charIndex(" ") to split the words up in the substring if thats what you want to do.
Using some of the [oracle internal similiarity] found in UTL_Match (https://docs.oracle.com/database/121/ARPLS/u_match.htm#ARPLS71219) matching...
This logic is more for matching names or descriptions that are 'Similar' and where phonetic spellings or typo's may cause the records not to match.
By adjusting the .5 below you can see how the %'s get you closer and closer to perfect matches.
with cte as (
select 'Content of values' val from dual union all
select 'Values identity' val from dual union all
select 'triple combo' from dual union all
select 'my combo'from dual union all
select 'sub-zero combo'from dual)
select a.*, b.*, utl_match.edit_distance_similarity(a.val, b.val) c, UTL_MATCH.JARO_WINKLER(a.val,b.val) JW
from cte a
cross join cte b
where UTL_MATCH.JARO_WINKLER(a.val,b.val) > .5
order by utl_match.edit_distance_similarity(a.val, b.val) desc
and screenshot of query/output.
Or we could use an inner join and > if we only want one way compairisons...
select a.*, b.*, utl_match.edit_distance_similarity(a.val, b.val) c, UTL_MATCH.JARO_WINKLER(a.val,b.val) JW
from cte a
inner join cte b
on A.Val > B.Val
where utl_match.jaro_winkler(a.val,b.val) > .5
order by utl_match.edit_distance_similarity(a.val, b.val) desc
this returns the 3 desired records.
But this does not explicitly check each any word matches. which was your base requirement. I just wanted you to be aware of alternatives.
I need to write a write a SQL query that selects values from a table based on several tuples of selection criteria. It could be done using a where clause like this :
where (a = 1 and b='a') or (a=5 and b='s')
Is the best way to select:
select a, pk from x where a in (1,5)
select b, pk from x where b in ('a','s')
and join the result of the two queries using the primary key?
do you mean something(a self join) like this:
select x.a, x.pk
from x
join x x2 on x.pk=x2.pk
where x.a in (1,5)
and x2.b in ('a','s')
?
You can use join on table expression from VALUES. You can add in VALUES as much rows as you want. It will work on MSSQL:
DECLARE #x TABLE ( a INT, b CHAR(1) )
INSERT INTO #x
VALUES ( 1, 'a' ),
( 1, 'b' ),
( 1, 'c' ),
( 2, 'd' ),
( 2, 'e' ),
( 5, 'f' ),
( 5, 's' )
SELECT x.*
FROM #x x
JOIN (
VALUES ( 1, 'a'),
( 5, 's')
) AS v( a, b ) ON x.a = v.a AND x.b = v.b
Output:
a b
1 a
5 s
Based on my understanding you want write a SQL that uses a combination of two filters. Here is a simple solution that will work in any database.
Create a new column say "COLUMN_NEW" in the same table or build a temp table or a view with a new column (plus existing columns from original table).
Insert concatenated values of column a and column b in "COLUMN_NEW". Based on the example mentioned by you values in "COLUMN_NEW" will be "1a" and "5s"
Now you may have a different syntax for concat in different databases. Example concat(a,b) in SQL server.
SQL to select records from the table will be select * from table where COLUMN_NEW in ("1a",5s");
I am using DB 2 and i am trying to write a query which checks multiple columns against a given set of values.Like field a, field b and field c against values x,y,z,f. One way that i can think for is writing same condition 3 times with or i.e. field a in ('x','y','z','f') or field b in .... and so on . Please let me know if there is some other efficient and easy way to accomplish this. I am looking for a query like if any of the condition is true return yes else no . Please suggest !
This may or may not work on as400:
create table a (a int not null, b int not null);
insert into a (a,b) values (1,1),(1,3),(2,3),(0,23);
select a.*
from a
where a in (1,2) or b in (1,2);
A B
----------- -----------
1 1
1 3
2 3
Rewriting as a join:
select a.*
from a
join ( values (1),(2) ) b (x)
on b.x in (a.a, a.b);
A B
----------- -----------
1 1
1 3
2 3
Assuming the column data types are the same, Create a subquery joining all the columns you want to search with your IN into one column with a union
SELECT *
FROM (
SELECT
YOUR_TABLE_PRIMARY_KEY
,A AS Col
FROM YOUR_TABLE
UNION ALL
SELECT
YOUR_TABLE_PRIMARY_KEY
,B AS Col
FROM YOUR_TABLE
UNION ALL
SELECT
YOUR_TABLE_PRIMARY_KEY
,C AS Col
FROM YOUR_TABLE
) AS SQ
WHERE
SQ.Col IN ('x','y','z','f')
Make sure to include the table key so you know which row the data refers to
You can create a regular expression that describe the set of characters and use it with xquery
Assuming you're on a supported version of the OS (tested on 7.1 TR6), this should work...
with sel (val) as (values ('x'),('y'),('f'))
select * from mytbl
where flda in (select val from sel)
or fldb in (select val from sel)
or fldc in (select val from sel)
Expanding on the above since your OP asked for "condition is true return yes else no"
Assuming you've got the key to a row to check, would 'yes' or the empty set be good enough? somekey is the key for the row you want to check.
with sel (val) as (values ('x'),('y'),('f'))
select 'yes' from mytbl
where thekey = somekey
and ( flda in (select val from sel)
or fldb in (select val from sel)
or fldc in (select val from sel)
)
It's actually rather difficult to return a value when you don't have a matching row. Here's one way. Note I've switch to 1=yes, 0=no..
with sel (val) as (values ('x'),('y'),('f'))
select 1 from mytbl
where thekey = somekey
and ( flda in (select val from sel)
or fldb in (select val from sel)
or fldc in (select val from sel)
)
UNION ALL
select 0
from sysibm.sysdummy1
order by 1 desc
fetch first row only
I need to copy data from original table and add custom column specified in query
Original table struct: col1, col2, col3
Insert table struct: x, col1, col2, col3
INSERT INTO newtable
SELECT *
FROM original
WHERE cond
and I'm getting this error
Column count doesn't match value count at row 1
HOW can I insert X value in this single query?
I tought something like this can pass
INSERT INTO newtable
SELECT 'x' = NULL, *
FROM original
WHERE cond
Any ideas?
Is it possible to use *? Because that table has so many columns and X has to be first value
I know this all is bad but I have to edit unbeliveable ugly db with even worse php code
The second statement is almost correct, but instead of 'x' = null, use null x (I'm assuming you want to store a null value in a column named x);
INSERT INTO newtable
SELECT null x, o.* FROM original o WHERE cond
Select Null as X, *
into newtable
from original
where ...
INSERT INTO newtable
SELECT null as x, col1, col2, col3 FROM original WHERE cond