Related
Following are the two tables in SQL Server: TABLE_A and TABLE_B
I need to get the output as follows:
Get IDs from TABLE_A where Exist = 0
We would get 100, 101 & 102
Now, among 100, 101 & 102, no other rows (in the same table) with the same ID value should have Exist = 1
Hence, 100 can't be selected as it has Exist = 1 in the 2nd row.
So, only 101 & 102 remain
With the remaining ID values (101 & 102), check against the ID column in TABLE_B where 'Exist' column value should not be equal to '1' in any of the rows
In TABLE_B, 4th row has Exist = 1 for 102. So, that can't be selected
We have only 101 now. This is required output and that should be selected.
Could you let me know how to write the simplest query to achieve this please? Let me know if the question needs to be improved.
You can use exists & not exists :
with t as (
select t1.*
from t1
where exists (select 1 from t1 t11 where t11.id = t1.id and t11.exists = 0) and
not exists (select 1 from t1 t11 where t11.id = t1.id and t11.exists = 1)
)
select t.*
from t
where not exists (select 1 from t2 where t.id = t2.id and t2.exists = 1);
Try:
SELECT
ID,
SUM(CAST(Exist AS int)) AS [Exists]
FROM
TABLE_A
GROUP BY ID
HAVING SUM(CAST(Exist AS bit)) = 0
will give you the answer to the first part. You can then JOIN this to a similar query for TABLE_B. That is a "simple" way to show how this works. You can write more complex queries as that from #Yogest Sharma
Like #Peter Smith mentioned, you can use the aggregate function SUM. Note that you would need a cast since you cannot use the aggregate function on a field that has a BIT datatype
;WITH CTE AS
(
SELECT ID, SUM(CAST(Exist AS INT)) AS AggExist FROM TABLE_A GROUP BY ID
UNION
SELECT ID, SUM(CAST(Exist AS INT)) As AggExist FROM TABLE_B GROUP BY ID
)
SELECT ID, SUM(AggExist) FROM CTE GROUP BY ID
HAVING SUM(AggExist) = 0
Here is the demo
I have a table that contains comma-separated values in a column In Postgres.
ID PRODS
--------------------------------------
1 ,142,10,75,
2 ,142,87,63,
3 ,75,73,2,58,
4 ,142,2,
Now I want a query where I can give a comma-separated string and it will tell me the number of matches between the input string and the string present in the row.
For instance, for input value ',142,87,', I want the output like
ID PRODS No. of Match
------------------------------------------------------------------------
1 ,142,10,75, 1
2 ,142,87,63, 2
3 ,75,73,2,58, 0
4 ,142,2, 1
Try this:
SELECT
*,
ARRAY(
SELECT
*
FROM
unnest(string_to_array(trim(both ',' from prods), ','))
WHERE
unnest = ANY(string_to_array(',142,87,', ','))
)
FROM
prods_table;
Output is:
1 ,142,10,75, {142}
2 ,142,87,63, {142,87}
3 ,75,73,2,58, {}
4 ,142,2, {142}
Add the cardinality(anyarray) function to the last column to get just a number of matches.
And consider changing your database design.
Check This.
select T.*,
COALESCE(No_of_Match,'0')
from TT T Left join
(
select ID,count(ID) No_of_Match
from (
select ID,unnest(string_to_array(trim(t.prods, ','), ',')) A
from TT t)a
Where A in ('142','87')
group by ID
)B
On T.Id=b.id
Demo Here
OutPut
If you install the intarray extension, this gets quite easy:
select id, prods, cardinality(string_to_array(trim(prods, ','), ',')::int[] & array[142,87])
from bad_design;
Otherwise it's a bit more complicated:
select bd.id, bd.prods, m.matches
from bad_design bd
join lateral (
select bd.id, count(v.p) as matches
from unnest(string_to_array(trim(bd.prods, ','), ',')) as l(p)
left join (
values ('142'),('87') --<< these are your input values
) v(p) on l.p = v.p
group by bd.id
) m on m.id = bd.id
order by bd.id;
Online example: http://rextester.com/ZIYS97736
But you should really fix your data model.
with data as
(
select *,
unnest(string_to_array(trim(both ',' from prods), ',') ) as v
from myTable
),
counts as
(
select id, count(t) as c from data
left join
( select unnest(string_to_array(',142,87,', ',') ) as t) tmp on tmp.t = data.v
group by id
order by id
)
select t1.id, t1.prods, t2.c as "No. of Match"
from myTable t1
inner join counts t2 on t1.id = t2.id;
I am searching with a query
--Code Format
SELECT COLA,COLB,COLC from MYTABLE where SWITCH IN (1,2,3);
If MYTABLE does not contain rows with SWITCH 1,2 or 3 I need default values returned along with the SWITCH value. How do I do it?
Below is my table format
COLA | COLB | COLC | SWITCH
------------------------------
A B C 1
a b c 2
i want a query when I search with
select * from MYTABLE where switch in (1,2,3)
That gets results like this --
COLA | COLB | COLC | SWITCH
------------------------------
A B C 1
a b c 2
NA NA NA 3
--Check to see if any row exists matching your conditions
IF NOT EXISTS (SELECT COLA,COLB,COLC from MYTABLE where SWITCH IN (1,2,3))
BEGIN
--Select your default values
END
ELSE
BEGIN
--Found rows, return them
SELECT COLA,COLB,COLC from MYTABLE where SWITCH IN (1,2,3)
END
if not exists( SELECT 1 from MYTABLE where SWITCH IN (1,2,3))
select default_value
How about:
SELECT COLA,COLB,COLC from MYTABLE where SWITCH IN (1,2,3)
union select 5555, 6666, 7777 where not exists (
SELECT COLA,COLB,COLC from MYTABLE where SWITCH IN (1,2,3)
);
5555, 6666, 7777 being the default row in case there aren't any rows matching your criteria.
Here is one way to tackle this. You need a table of the SWITCH values you want to look at. Then a simple left join makes this super easy.
select ColA
, ColB
, ColC
v.Switch
from
(
values
(1)
, (2)
, (3)
)v (Switch)
left join YourTable yt on yt.Switch = v.Switch
You can Use a Split Function And Left Join As Shown Below:
Select ISNULL(ColA,'NA') As ColA,ISNULL(ColB,'NA') As ColB,ISNULL(ColC,'NA') As ColC,ISNULL(Switch,a.splitdata)
from [dbo].[fnSplitString]('1,2,3',',') a
LEFT JOIN #MYTABLE t on a.splitdata=t.Switch
[dbo].[fnSplitString] is a Split Function with 2 arguments - Delimeter Separated String and Delimeter and Output a Table.
EDIT:
Given the new explanation, I changed the answer completely. I think I got your question now:
SELECT * FROM MYTABLE AS mt
RIGHT JOIN (SELECT 1 AS s UNION SELECT 2 AS s UNION SELECT 3 AS s) AS st
ON st.s = mt.SWITCH
You could change the SELECT 1 AS s UNION SELECT 2 AS s UNION SELECT 3 AS spart to a subquery that results in all possible values SWITCH could assume. E.g.:
SELECT DISTINCT SWITCH FROM another_table_with_all_switches
If all want is the value of switch that is not in MYTABLE, not the whole table with null values, you could try:
SELECT * FROM
(SELECT 1 AS s UNION SELECT 2 AS s UNION SELECT 3) AS st
WHERE st.s NOT IN (SELECT DISTINCT SWITCH FROM MYTABLE)
I have a sqlite query that returns something like the following with columns [letter, number]:
("a", 1)
("a", 2)
("b", 3)
("c", 3)
I want to retrieve the number column as 0 if the letter is distinct. How is it done?
Expected output:
("a", 1)
("a", 2)
("b", 0)
("c", 0)
SELECT tba.mychar
-- if tbu.mychar is null, then the letter is not unique
-- when it happens, the letter is not "unique" thus use the number column
-- else use zero for "unique" letters
, CASE WHEN tbu.mychar IS NULL THEN tba.mynum ELSE 0 END AS newnum
FROM mytab tba
LEFT JOIN (
-- this subquery only returns the letters that don't repeat
SELECT mychar
FROM mytab
GROUP BY mychar
HAVING COUNT(*) = 1
) AS tbu ON tba.mychar=tbu.mychar
You can use a sub-query:
select t1.col1,
case when t2.cnt > 1 then t1.col2 else 0 end col2
from table1 t1
left join
(
select count(*) as cnt, col1
from table1
group by col1
) t2
on t1.col1 = t2.col1
See SQL Fiddle with Demo
How about (SQL Fiddle):
SELECT Q.letter,
CASE WHEN (SELECT COUNT(*) FROM (query) QQ WHERE QQ.letter = Q.letter) = 1 THEN 0
ELSE Q.number
END AS number
FROM (query) Q
Note, replace "query" with the query that generates your first result.
It's possible to do this using a UNION ALL of 2 separate statements (one for repeated letters and one for letters that only occur once):
SELECT letter, number
FROM tableName
WHERE letter IN (
SELECT letter
FROM tableName
GROUP BY letter
HAVING COUNT(1) > 1
)
UNION ALL
SELECT letter, 0
FROM tableName
WHERE letter IN (
SELECT letter
FROM tableName
GROUP BY letter
HAVING COUNT(1) = 1
)
I'd like to find the first "gap" in a counter column in an SQL table. For example, if there are values 1,2,4 and 5 I'd like to find out 3.
I can of course get the values in order and go through it manually, but I'd like to know if there would be a way to do it in SQL.
In addition, it should be quite standard SQL, working with different DBMSes.
In MySQL and PostgreSQL:
SELECT id + 1
FROM mytable mo
WHERE NOT EXISTS
(
SELECT NULL
FROM mytable mi
WHERE mi.id = mo.id + 1
)
ORDER BY
id
LIMIT 1
In SQL Server:
SELECT TOP 1
id + 1
FROM mytable mo
WHERE NOT EXISTS
(
SELECT NULL
FROM mytable mi
WHERE mi.id = mo.id + 1
)
ORDER BY
id
In Oracle:
SELECT *
FROM (
SELECT id + 1 AS gap
FROM mytable mo
WHERE NOT EXISTS
(
SELECT NULL
FROM mytable mi
WHERE mi.id = mo.id + 1
)
ORDER BY
id
)
WHERE rownum = 1
ANSI (works everywhere, least efficient):
SELECT MIN(id) + 1
FROM mytable mo
WHERE NOT EXISTS
(
SELECT NULL
FROM mytable mi
WHERE mi.id = mo.id + 1
)
Systems supporting sliding window functions:
SELECT -- TOP 1
-- Uncomment above for SQL Server 2012+
previd
FROM (
SELECT id,
LAG(id) OVER (ORDER BY id) previd
FROM mytable
) q
WHERE previd <> id - 1
ORDER BY
id
-- LIMIT 1
-- Uncomment above for PostgreSQL
Your answers all work fine if you have a first value id = 1, otherwise this gap will not be detected. For instance if your table id values are 3,4,5, your queries will return 6.
I did something like this
SELECT MIN(ID+1) FROM (
SELECT 0 AS ID UNION ALL
SELECT
MIN(ID + 1)
FROM
TableX) AS T1
WHERE
ID+1 NOT IN (SELECT ID FROM TableX)
There isn't really an extremely standard SQL way to do this, but with some form of limiting clause you can do
SELECT `table`.`num` + 1
FROM `table`
LEFT JOIN `table` AS `alt`
ON `alt`.`num` = `table`.`num` + 1
WHERE `alt`.`num` IS NULL
LIMIT 1
(MySQL, PostgreSQL)
or
SELECT TOP 1 `num` + 1
FROM `table`
LEFT JOIN `table` AS `alt`
ON `alt`.`num` = `table`.`num` + 1
WHERE `alt`.`num` IS NULL
(SQL Server)
or
SELECT `num` + 1
FROM `table`
LEFT JOIN `table` AS `alt`
ON `alt`.`num` = `table`.`num` + 1
WHERE `alt`.`num` IS NULL
AND ROWNUM = 1
(Oracle)
The first thing that came into my head. Not sure if it's a good idea to go this way at all, but should work. Suppose the table is t and the column is c:
SELECT
t1.c + 1 AS gap
FROM t as t1
LEFT OUTER JOIN t as t2 ON (t1.c + 1 = t2.c)
WHERE t2.c IS NULL
ORDER BY gap ASC
LIMIT 1
Edit: This one may be a tick faster (and shorter!):
SELECT
min(t1.c) + 1 AS gap
FROM t as t1
LEFT OUTER JOIN t as t2 ON (t1.c + 1 = t2.c)
WHERE t2.c IS NULL
This works in SQL Server - can't test it in other systems but it seems standard...
SELECT MIN(t1.ID)+1 FROM mytable t1 WHERE NOT EXISTS (SELECT ID FROM mytable WHERE ID = (t1.ID + 1))
You could also add a starting point to the where clause...
SELECT MIN(t1.ID)+1 FROM mytable t1 WHERE NOT EXISTS (SELECT ID FROM mytable WHERE ID = (t1.ID + 1)) AND ID > 2000
So if you had 2000, 2001, 2002, and 2005 where 2003 and 2004 didn't exist, it would return 2003.
The following solution:
provides test data;
an inner query that produces other gaps; and
it works in SQL Server 2012.
Numbers the ordered rows sequentially in the "with" clause and then reuses the result twice with an inner join on the row number, but offset by 1 so as to compare the row before with the row after, looking for IDs with a gap greater than 1. More than asked for but more widely applicable.
create table #ID ( id integer );
insert into #ID values (1),(2), (4),(5),(6),(7),(8), (12),(13),(14),(15);
with Source as (
select
row_number()over ( order by A.id ) as seq
,A.id as id
from #ID as A WITH(NOLOCK)
)
Select top 1 gap_start from (
Select
(J.id+1) as gap_start
,(K.id-1) as gap_end
from Source as J
inner join Source as K
on (J.seq+1) = K.seq
where (J.id - (K.id-1)) <> 0
) as G
The inner query produces:
gap_start gap_end
3 3
9 11
The outer query produces:
gap_start
3
Inner join to a view or sequence that has a all possible values.
No table? Make a table. I always keep a dummy table around just for this.
create table artificial_range(
id int not null primary key auto_increment,
name varchar( 20 ) null ) ;
-- or whatever your database requires for an auto increment column
insert into artificial_range( name ) values ( null )
-- create one row.
insert into artificial_range( name ) select name from artificial_range;
-- you now have two rows
insert into artificial_range( name ) select name from artificial_range;
-- you now have four rows
insert into artificial_range( name ) select name from artificial_range;
-- you now have eight rows
--etc.
insert into artificial_range( name ) select name from artificial_range;
-- you now have 1024 rows, with ids 1-1024
Then,
select a.id from artificial_range a
where not exists ( select * from your_table b
where b.counter = a.id) ;
This one accounts for everything mentioned so far. It includes 0 as a starting point, which it will default to if no values exist as well. I also added the appropriate locations for the other parts of a multi-value key. This has only been tested on SQL Server.
select
MIN(ID)
from (
select
0 ID
union all
select
[YourIdColumn]+1
from
[YourTable]
where
--Filter the rest of your key--
) foo
left join
[YourTable]
on [YourIdColumn]=ID
and --Filter the rest of your key--
where
[YourIdColumn] is null
For PostgreSQL
An example that makes use of recursive query.
This might be useful if you want to find a gap in a specific range
(it will work even if the table is empty, whereas the other examples will not)
WITH
RECURSIVE a(id) AS (VALUES (1) UNION ALL SELECT id + 1 FROM a WHERE id < 100), -- range 1..100
b AS (SELECT id FROM my_table) -- your table ID list
SELECT a.id -- find numbers from the range that do not exist in main table
FROM a
LEFT JOIN b ON b.id = a.id
WHERE b.id IS NULL
-- LIMIT 1 -- uncomment if only the first value is needed
My guess:
SELECT MIN(p1.field) + 1 as gap
FROM table1 AS p1
INNER JOIN table1 as p3 ON (p1.field = p3.field + 2)
LEFT OUTER JOIN table1 AS p2 ON (p1.field = p2.field + 1)
WHERE p2.field is null;
I wrote up a quick way of doing it. Not sure this is the most efficient, but gets the job done. Note that it does not tell you the gap, but tells you the id before and after the gap (keep in mind the gap could be multiple values, so for example 1,2,4,7,11 etc)
I'm using sqlite as an example
If this is your table structure
create table sequential(id int not null, name varchar(10) null);
and these are your rows
id|name
1|one
2|two
4|four
5|five
9|nine
The query is
select a.* from sequential a left join sequential b on a.id = b.id + 1 where b.id is null and a.id <> (select min(id) from sequential)
union
select a.* from sequential a left join sequential b on a.id = b.id - 1 where b.id is null and a.id <> (select max(id) from sequential);
https://gist.github.com/wkimeria/7787ffe84d1c54216f1b320996b17b7e
Here is an alternative to show the range of all possible gap values in portable and more compact way :
Assume your table schema looks like this :
> SELECT id FROM your_table;
+-----+
| id |
+-----+
| 90 |
| 103 |
| 104 |
| 118 |
| 119 |
| 120 |
| 121 |
| 161 |
| 162 |
| 163 |
| 185 |
+-----+
To fetch the ranges of all possible gap values, you have the following query :
The subquery lists pairs of ids, each of which has the lowerbound column being smaller than upperbound column, then use GROUP BY and MIN(m2.id) to reduce number of useless records.
The outer query further removes the records where lowerbound is exactly upperbound - 1
My query doesn't (explicitly) output the 2 records (YOUR_MIN_ID_VALUE, 89) and (186, YOUR_MAX_ID_VALUE) at both ends, that implicitly means any number in both of the ranges hasn't been used in your_table so far.
> SELECT m3.lowerbound + 1, m3.upperbound - 1 FROM
(
SELECT m1.id as lowerbound, MIN(m2.id) as upperbound FROM
your_table m1 INNER JOIN your_table
AS m2 ON m1.id < m2.id GROUP BY m1.id
)
m3 WHERE m3.lowerbound < m3.upperbound - 1;
+-------------------+-------------------+
| m3.lowerbound + 1 | m3.upperbound - 1 |
+-------------------+-------------------+
| 91 | 102 |
| 105 | 117 |
| 122 | 160 |
| 164 | 184 |
+-------------------+-------------------+
select min([ColumnName]) from [TableName]
where [ColumnName]-1 not in (select [ColumnName] from [TableName])
and [ColumnName] <> (select min([ColumnName]) from [TableName])
Here is standard a SQL solution that runs on all database servers with no change:
select min(counter + 1) FIRST_GAP
from my_table a
where not exists (select 'x' from my_table b where b.counter = a.counter + 1)
and a.counter <> (select max(c.counter) from my_table c);
See in action for;
PL/SQL via Oracle's livesql,
MySQL via sqlfiddle,
PostgreSQL via sqlfiddle
MS Sql via sqlfiddle
It works for empty tables or with negatives values as well. Just tested in SQL Server 2012
select min(n) from (
select case when lead(i,1,0) over(order by i)>i+1 then i+1 else null end n from MyTable) w
If You use Firebird 3 this is most elegant and simple:
select RowID
from (
select `ID_Column`, Row_Number() over(order by `ID_Column`) as RowID
from `Your_Table`
order by `ID_Column`)
where `ID_Column` <> RowID
rows 1
-- PUT THE TABLE NAME AND COLUMN NAME BELOW
-- IN MY EXAMPLE, THE TABLE NAME IS = SHOW_GAPS AND COLUMN NAME IS = ID
-- PUT THESE TWO VALUES AND EXECUTE THE QUERY
DECLARE #TABLE_NAME VARCHAR(100) = 'SHOW_GAPS'
DECLARE #COLUMN_NAME VARCHAR(100) = 'ID'
DECLARE #SQL VARCHAR(MAX)
SET #SQL =
'SELECT TOP 1
'+#COLUMN_NAME+' + 1
FROM '+#TABLE_NAME+' mo
WHERE NOT EXISTS
(
SELECT NULL
FROM '+#TABLE_NAME+' mi
WHERE mi.'+#COLUMN_NAME+' = mo.'+#COLUMN_NAME+' + 1
)
ORDER BY
'+#COLUMN_NAME
-- SELECT #SQL
DECLARE #MISSING_ID TABLE (ID INT)
INSERT INTO #MISSING_ID
EXEC (#SQL)
--select * from #MISSING_ID
declare #var_for_cursor int
DECLARE #LOW INT
DECLARE #HIGH INT
DECLARE #FINAL_RANGE TABLE (LOWER_MISSING_RANGE INT, HIGHER_MISSING_RANGE INT)
DECLARE IdentityGapCursor CURSOR FOR
select * from #MISSING_ID
ORDER BY 1;
open IdentityGapCursor
fetch next from IdentityGapCursor
into #var_for_cursor
WHILE ##FETCH_STATUS = 0
BEGIN
SET #SQL = '
DECLARE #LOW INT
SELECT #LOW = MAX('+#COLUMN_NAME+') + 1 FROM '+#TABLE_NAME
+' WHERE '+#COLUMN_NAME+' < ' + cast( #var_for_cursor as VARCHAR(MAX))
SET #SQL = #sql + '
DECLARE #HIGH INT
SELECT #HIGH = MIN('+#COLUMN_NAME+') - 1 FROM '+#TABLE_NAME
+' WHERE '+#COLUMN_NAME+' > ' + cast( #var_for_cursor as VARCHAR(MAX))
SET #SQL = #sql + 'SELECT #LOW,#HIGH'
INSERT INTO #FINAL_RANGE
EXEC( #SQL)
fetch next from IdentityGapCursor
into #var_for_cursor
END
CLOSE IdentityGapCursor;
DEALLOCATE IdentityGapCursor;
SELECT ROW_NUMBER() OVER(ORDER BY LOWER_MISSING_RANGE) AS 'Gap Number',* FROM #FINAL_RANGE
Found most of approaches run very, very slow in mysql. Here is my solution for mysql < 8.0. Tested on 1M records with a gap near the end ~ 1sec to finish. Not sure if it fits other SQL flavours.
SELECT cardNumber - 1
FROM
(SELECT #row_number := 0) as t,
(
SELECT (#row_number:=#row_number+1), cardNumber, cardNumber-#row_number AS diff
FROM cards
ORDER BY cardNumber
) as x
WHERE diff >= 1
LIMIT 0,1
I assume that sequence starts from `1`.
If your counter is starting from 1 and you want to generate first number of sequence (1) when empty, here is the corrected piece of code from first answer valid for Oracle:
SELECT
NVL(MIN(id + 1),1) AS gap
FROM
mytable mo
WHERE 1=1
AND NOT EXISTS
(
SELECT NULL
FROM mytable mi
WHERE mi.id = mo.id + 1
)
AND EXISTS
(
SELECT NULL
FROM mytable mi
WHERE mi.id = 1
)
DECLARE #Table AS TABLE(
[Value] int
)
INSERT INTO #Table ([Value])
VALUES
(1),(2),(4),(5),(6),(10),(20),(21),(22),(50),(51),(52),(53),(54),(55)
--Gaps
--Start End Size
--3 3 1
--7 9 3
--11 19 9
--23 49 27
SELECT [startTable].[Value]+1 [Start]
,[EndTable].[Value]-1 [End]
,([EndTable].[Value]-1) - ([startTable].[Value]) Size
FROM
(
SELECT [Value]
,ROW_NUMBER() OVER(PARTITION BY 1 ORDER BY [Value]) Record
FROM #Table
)AS startTable
JOIN
(
SELECT [Value]
,ROW_NUMBER() OVER(PARTITION BY 1 ORDER BY [Value]) Record
FROM #Table
)AS EndTable
ON [EndTable].Record = [startTable].Record+1
WHERE [startTable].[Value]+1 <>[EndTable].[Value]
If the numbers in the column are positive integers (starting from 1) then here is how to solve it easily. (assuming ID is your column name)
SELECT TEMP.ID
FROM (SELECT ROW_NUMBER() OVER () AS NUM FROM 'TABLE-NAME') AS TEMP
WHERE ID NOT IN (SELECT ID FROM 'TABLE-NAME')
ORDER BY 1 ASC LIMIT 1
SELECT ID+1 FROM table WHERE ID+1 NOT IN (SELECT ID FROM table) ORDER BY 1;