Related
I have a question regarding splitting rows based on column value
My example data set is :
id ExpenseType Price
------------------------
1 Car 100
2 Hotel 50
I want to split rows those have some Expense Types such as Car into two rows . Others should remain as one row.
First row Price *70
Second Row Price *30
Returned dataset should be
id ExpenseType Price
-----------------------
1 Car 70
1 Car 30
2 Hotel 50
Thanks for your answers in advance
If you want to split more expense types than car you could use:
WITH r AS (
SELECT 'Car' AS ExpenseType, 0.7 AS Ratio
UNION SELECT 'Car' AS ExpenseType, 0.3 AS Ratio
-- add more ExpenseTypes/Ratios here
)
SELECT
t.id,
t.ExpenseType,
t.Price * ISNULL(r.Ratio, 1.0) AS Price
FROM
your_table t
LEFT OUTER JOIN r ON t.ExpenseType = r.ExpenseType
A simple way uses union all:
select id, expensetype, price
from t
where expensetype <> 'Car'
union all
select id, expensetype, price * 0.7
from t
where expensetype = 'Car'
union all
select id, expensetype, price * 0.3
from t
where expensetype = 'Car';
This is not the most efficient method. For that, a cross apply with filtering logic is better:
select t.id, v.*
from t cross apply
(values (NULL, price), ('Car', price * 0.3), ('Car', price * 0.7)
) v(expensetype, price)
where v.expensetype = t.expense_type or
v.expensetype <> 'Car' and t.expense_type is null;
A less simple way is to use an OUTER APPLY
CREATE TABLE YourSampleData
(
Id INT IDENTITY(1,1) PRIMARY KEY,
ExpenseType VARCHAR(30) NOT NULL,
Price INT NOT NULL DEFAULT 0
);
INSERT INTO YourSampleData
(ExpenseType, Price) VALUES
('Car', 100)
,('Hotel', 50)
,('Gold', 1)
;
SELECT Id, ExpenseType
, COALESCE(a.Price, t.Price) AS Price
FROM YourSampleData t
OUTER APPLY
(
SELECT Price * Perc AS Price
FROM (VALUES
('Car',0.3E0), ('Car',0.7E0)
,('Gold',1.618E0)
) AS v(ExpType, Perc)
WHERE t.ExpenseType = v.ExpType
) a
GO
Id | ExpenseType | Price
-: | :---------- | ----:
1 | Car | 30
1 | Car | 70
2 | Hotel | 50
3 | Gold | 1.618
db<>fiddle here
I ran into a similar need, here is my solution.
Problem statement:
My organization is switching from an in-house build system to a third-party system. Numerical values in the original system surpassed the value size that the destination system could handle. The third-party system will not allow us to increase the field size, as a result we need to split the data up into values that do not surpass the field size limit.
Details:
Destination system can only support values under 1 billion (can include a negative sign)
Example:
DROP TABLE IF EXISTS #MyDemoData /* Generate some fake data for the demo */
SELECT item_no = 1, item_description = 'zero asset', amount = 0 INTO #MyDemoData
UNION SELECT item_no = 2, item_description = 'small asset', amount = 5100000
UNION SELECT item_no = 3, item_description = 'mid asset', amount = 510000000
UNION SELECT item_no = 4, item_description = 'large asset', amount = 5100000000
UNION SELECT item_no = 5, item_description = 'large debt', amount = -2999999999.99
SELECT * FROM #MyDemoData
DECLARE #limit_size INT = 1000000000
DROP TABLE IF EXISTS #groupings;
WITH
max_groups AS
(
SELECT max_groups=100
)
,groups AS
(
SELECT 1 AS [group]
UNION ALL
SELECT [group]+1
FROM groups
JOIN max_groups ON 1=1
WHERE [group]+1<=max_groups
)
,group_rows AS
(
SELECT 0 AS [row]
UNION ALL
SELECT [row]+1
FROM group_rows
JOIN max_groups ON 1=1
WHERE [row]+1<=max_groups
)
,groupings AS
(
SELECT [group],[row]
FROM group_rows
CROSS JOIN groups
WHERE [row] <= [group]
)
SELECT * INTO #groupings FROM groupings;
WITH /* Split out items that are under the limit and over the limit */
t1 AS /* Identify rows that are over the limit and by how many multiples over it is */
(
SELECT
item_no
, item_description
, amount
, over_limit = FLOOR(ABS(amount/#limit_size))
FROM #MyDemoData
)
SELECT /* select the items that are under the limit and do not need manipulated */
item_no
, item_description
, amount = CAST(amount AS DECIMAL(16,2))
FROM t1
WHERE ABS([amount]) < #limit_size
UNION ALL /* select the items that are over the limit, join on the groupings cte and calculate the split amounts */
SELECT
item_no
, item_description
, [Amount] = CAST(
CASE
WHEN row != 0 THEN (#limit_size-1) * ([amount]/ABS([amount]))
ELSE (ABS([amount]) - (t1.over_limit * #limit_size) + t1.over_limit) * ([amount]/ABS([amount]))
END AS DECIMAL(16,2))
FROM t1
JOIN #groupings bg ON t1.over_limit = bg.[group]
WHERE ABS([amount]) >= #limit_size
ORDER BY item_no
I'm trying to copy data from one table to another, while transposing it and combining it into appropriate rows, with different columns in the second table.
First time posting. Yes this may seem simple to everyone here. I have tried for a couple hours to solve this. I do not have much support internally and have learned a great deal on this forum and managed to get so much accomplished with your other help examples. I appreciate any help with this.
Table 1 has the data in this format.
Type Date Value
--------------------
First 2019 1
First 2020 2
Second 2019 3
Second 2020 4
Table 2 already has the Date rows populated and columns created. It is waiting for the Values from Table 1 to be placed in the appropriate column/row.
Date First Second
------------------
2019 1 3
2020 2 4
For an update, I might use two joins:
update t2
set first = tf.value,
second = ts.value
from table2 t2 left join
table1 tf
on t2.date = tf.date and tf.type = 'First' left join
table1 ts
on t2.date = ts.date and ts.type = 'Second'
where tf.date is not null or ts.date is not null;
use conditional aggregation
select date,max(case when type='First' then value end) as First,
max(case when type='Second' then value end) as Second from t
group by date
You can do conditional aggregation :
select date,
max(case when type = 'first' then value end) as first,
max(case when type = 'Second' then value end) as Second
from table t
group by date;
After that you can use cte :
with cte as (
select date,
max(case when type = 'first' then value end) as first,
max(case when type = 'Second' then value end) as Second
from table t
group by date
)
update t2
set t2.First = t1.First,
t2.Second = t1.Second
from table2 t2 inner join
cte t1
on t1.date = t2.date;
Seems like you're after a PIVOT
DECLARE #Table1 TABLE
(
[Type] NVARCHAR(100)
, [Date] INT
, [Value] INT
);
DECLARE #Table2 TABLE(
[Date] int
,[First] int
,[Second] int
)
INSERT INTO #Table1 (
[Type]
, [Date]
, [Value]
)
VALUES ( 'First', 2019, 1 )
, ( 'First', 2020, 2 )
, ( 'Second', 2019, 3 )
, ( 'Second', 2020, 4 );
INSERT INTO #Table2 (
[Date]
)
VALUES (2019),(2020)
--Show us what's in the tables
SELECT * FROM #Table1
SELECT * FROM #Table2
--How to pivot the data from Table 1
SELECT * FROM #Table1
PIVOT (
MAX([Value]) --Pivot on this Column
FOR [Type] IN ( [First], [Second] ) --Make column where [Value] is in one of this
) AS [pvt] --Table alias
--which gives
--Date First Second
------------- ----------- -----------
--2019 1 3
--2020 2 4
--Using that we can update #Table2
UPDATE [tbl2]
SET [tbl2].[First] = pvt.[First]
,[tbl2].[Second] = pvt.[Second]
FROM #Table1 tbl1
PIVOT (
MAX([Value]) --Pivot on this Column
FOR [Type] IN ( [First], [Second] ) --Make column where [Value] is in one of this
) AS [pvt] --Table alias
INNER JOIN #Table2 tbl2 ON [tbl2].[Date] = [pvt].[Date]
--Results from #Table 2 after updated
SELECT * FROM #Table2
--which gives
--Date First Second
------------- ----------- -----------
--2019 1 3
--2020 2 4
I saw related questions but I really don't understand how to do this.
I have a table name "tbl_image"
id keys image_count
1 0001 1
2 0001 3
3 0001 5
4 0003 6
5 0003 9
I want my output to look like this
If I select where the keys = '0001'
output
2
4
And when I select where the keys = '0003'
output
7
8
Thanks in advance.
One method is to use recursive cte
;with cte as
(
select id, image_count,min(image_count) over (partition by Keys) cm, keys from table
union all
select id, image_count, cm+1, keys from cte c
where c.image_count > c.cm
)
select distinct c.cm as Missing from cte c
left join table t on t.keys = c.keys and t.image_count = c.cm
where c.keys = '0003' and t.image_count is null
Result :
Missing
7
8
Use recursive query
with result as
(
select min(image_count) + 1 output,
(select max(image_count) - 1 from tbl_image where keys = '0003') max_output
from tbl_image
where keys = '0003'
union all
select output + 1, max_output
from result
where output < max_output
)
select output
from result
where not exists (select 1 from tbl_image where image_count = output)
dbfiddle demo
Try this:
DECLARE #tbl_image TABLE(ID int, Keys VARCHAR(10),Image_Count INT)
INSERT INTO #tbl_image VALUES (1,'0001',1)
INSERT INTO #tbl_image VALUES (2,'0001',3)
INSERT INTO #tbl_image VALUES (3,'0001',5)
INSERT INTO #tbl_image VALUES (4,'0003',6)
INSERT INTO #tbl_image VALUES (5,'0003',9)
SELECT DISTINCT n = number
FROM Master.dbo.[spt_values]
WHERE number BETWEEN (SELECT MIN(Image_Count) FROM #tbl_image WHERE Keys='0001')
AND (SELECT MAX(Image_Count) FROM #tbl_image WHERE Keys='0001')
AND number NOT IN(SELECT Image_Count FROM #tbl_image WHERE Keys='0001')
OutPut:
2
4
i have following table "vehicle_data" :
ID ALERT_TYPE VALUE
58 2 1
58 1 1
104 1 1
104 2 1
Here alert_type = 2 is for GPS value and alert_type=1 is for engine_value .
so if alert_type=2 and its value is =1 then it means its value is correct.
when alert_type=2 and its value is =0 then it means its value is wrong.
same for alert_type=1
so now here i want the following output:
ID gps engine_value
58 1 1
104 1 1
how can i perform this query??
You can do it like this.
SELECT ID
,CASE WHEN [ALERT_TYPE]=2 and [value ]=1 THEN 1 ELSE 0 END as gps
,CASE WHEN [ALERT_TYPE]=1 and [value ]=1 THEN 1 ELSE 0 END as engine
FROM vehicle_data
SELECT ID, alert_type=2 AS gps, alert_type=1 AS [engine] FROM vehicle_data WHERE value=1;
EDITED to account for your explanation of VALUE.
Schema
CREATE TABLE table3 (id int, ALERT_TYPE int)
INSERT table3 VALUES (58, 1), (58, 2), (104, 1), (104, 2)
Query
SELECT *
FROM (
SELECT ID
,ROW_NUMBER() OVER (
PARTITION BY id ORDER BY id
) AS row_num
,gps = CASE
WHEN ALERT_TYPE = 2
THEN 1
ELSE 0
END
,engine = CASE
WHEN ALERT_TYPE = 1
THEN 1
ELSE 0
END
FROM table3
) a
WHERE a.row_num = 1
Output
ID gps engine
58 1 0
104 0 1
One possible way using subqueries :
select
Ids.ID
, gps.VALUE 'gps'
, engine_value.VALUE 'engine_value'
from (select distinct ID from vehicle_data) Ids
left join
(select ID, VALUE from vehicle_data where ALERT_TYPE = 2) gps
on gps.ID = Ids.ID
left join
(select ID, VALUE from vehicle_data where ALERT_TYPE = 1) engine_value
on engine_value.ID = Ids.ID
[SQL Fiddle demo]
I hope this should work for you,
Select ID,sum(gps) as gps ,sum(engine) as engine from
(SELECT ID
,CASE WHEN [ALERT_TYPE]=2 and [value ]=1 THEN 1 ELSE 0 END as gps
,CASE WHEN [ALERT_TYPE]=1 and [value ]=1 THEN 1 ELSE 0 END as engine
FROM vehicle_data
)a
group by id
select x.id,x.alert_type as GPS,x.value as engine_value from (
select ID,alert_type,value,ROW_NUMBER() over (partition by id order by alert_type ) as Rnk from mytable
)x
where Rnk=1
Please check this query in SQL :
create table mytable (id int, alert_type int, value int);
insert into mytable (id, alert_type, value)
values (58, 2, 1),
(58, 1, 1),
(104, 1, 1),
(104, 2, 1);
SELECT distinct ID
,(select count (id) from mytable mt where mt.id=mytable.id and mt.[ALERT_TYPE]=2 and mt.[value ]=1) as gps
,(select count (id) from mytable mt where mt.id=mytable.id and mt.[ALERT_TYPE]=1 and mt.[value ]=1) as engine
FROM mytable
BASED ON YOUR QUESTION I BELIEVE YOU WANT THE DATA IN COLUMN AND TO SUIT YOUR REQUIREMENT I HAVE MADE A SQL FIDDLE WORKING - CODE IS ALSO MENTIONED BELOW -
HERE YOU GO WITH THE WORKING FIDDLE -
WORKING DEMO
SQL CODE FOR REFERNECE -
CREATE TABLE ALERTS (ID INT, ALERT_TYPE INT, VALUE INT)
INSERT INTO ALERTS VALUES (58,2,1)
INSERT INTO ALERTS VALUES (58,1,0)
INSERT INTO ALERTS VALUES (104,1,1)
INSERT INTO ALERTS VALUES (104,2,0)
CREATE TABLE ALERTSVALUE (ID INT, gps INT,engine INT)
INSERT INTO ALERTSVALUE VALUES (58,1,0)
INSERT INTO ALERTSVALUE VALUES (104,0,1)
SELECT A.ID,
CASE A.ALERT_TYPE WHEN 2 THEN 1 ELSE 0 END AS GPS,
CASE A.ALERT_TYPE WHEN 1 THEN 1 ELSE 0 END AS ENGINE_VALUE,
A.VALUE FROM ALERTS A WHERE A.VALUE = 1
EDIT BASED ON COMMENT - TO MERGE THE ROWS FOR BOTH GPS AND ENGINE_VALUE:
SELECT X.ID,X.ALERT_TYPE as GPS,X.VALUE as ENGINE_VALUE
FROM (
SELECT ID,ALERT_TYPE ,VALUE ,ROW_NUMBER() OVER (PARTITION BY ID ORDER BY alert_type ) AS [Rank] FROM ALERTS
)X
WHERE [Rank]=1
SQL FIDDLE DEMO
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;