Related
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;
Good day.
I seem to be struggling with what seems like a simple problem.
I have a table that has a value connected to a date (Monthly) for a finite number of ID's
ie. Table1
ID | Date ---| Value
01 | 2015-01 | val1
01 | 2015-02 | val2
02 | 2015-01 | val1
02 | 2015-03 | val2
So ID: 02 does not have a value for date 2015-02.
I would like to return all ID's and Dates that do not have a value.
Date range is: select distinct date from Table1
I can't seem to think outside the realms of selecting and joining on the same table.
I need to include the ID in my select to I can somehow select the ID and Date range that exists for that ID and compare to the entire date range, to get all the dates for each ID that isn't in the "entire" date range.
Please advise.
Thank you
Not very clear about your last two sentences. But you can play with the following query with different #max_days and #min_date:
-- DROP TABLE table1;
CREATE TABLE table1(ID int not null, `date` date not null, value varchar(64) not null);
INSERT table1(ID,`date`,value)
VALUES (1,'2015-01-01','v1'),(1,'2015-01-02','v2'),(2,'2015-01-01','v1'),(2,'2015-01-03','v2'),(4,'2015-01-01','v1'),(4,'2015-01-04','v2');
SELECT * FROM table1;
SET #day=0;
SET #max_days=5;
SET #min_date='2015-01-01';
SELECT i.ID,d.`date`
FROM (SELECT DISTINCT ID FROM table1) i
CROSS JOIN (
SELECT TIMESTAMPADD(DAY,#day,#min_date) AS `date`,#day:=#day+1 AS day_num
FROM table1 WHERE #day<#max_days) d
LEFT JOIN table1 t
ON t.ID=i.ID
AND t.`date`=d.`date`
WHERE t.`date` IS NULL
ORDER BY i.ID,d.`date`;
I now understand your requirement of dates being taken from the table; you want to find any gaps in the date ranges for each id.
This does what you need, but can probably be improved. Explanation below and you can view a working example.
DROP TABLE IF EXISTS Table1;
DROP TABLE IF EXISTS Year_Month_Calendar;
CREATE TABLE Table1 (
id INTEGER
,date CHAR(7)
,value CHAR(4)
);
INSERT INTO Table1
VALUES
(1,'2015-01','val1')
,(1,'2015-02','val2')
,(2,'2015-01','val1')
,(2,'2015-03','val1');
CREATE TABLE Year_Month_Calendar (
date CHAR(10)
);
INSERT INTO Year_Month_Calendar
VALUES
('2015-01')
,('2015-02')
,('2015-03');
SELECT ID_Year_Month.id, ID_Year_Month.date, Table1.id, Table1.date
FROM (
SELECT Distinct_ID.id, Year_Month_Calendar.date
FROM Year_Month_Calendar
CROSS JOIN
( SELECT DISTINCT id FROM Table1 ) AS Distinct_ID
WHERE Year_Month_Calendar.date >= (SELECT MIN(date) FROM Table1 WHERE id=Distinct_ID.ID)
AND Year_Month_Calendar.date <= (SELECT MAX(date) FROM Table1 WHERE id=Distinct_ID.ID)
) AS ID_Year_Month
LEFT JOIN Table1
ON ID_Year_Month.id = Table1.id AND ID_Year_Month.date = Table1.date
-- WHERE Table1.id IS NULL
ORDER BY ID_Year_Month.id, ID_Year_Month.date
Explanation
You need a calendar table which contains all dates (year/months) to cover the data you are querying.
CREATE TABLE Year_Month_Calendar (
date CHAR(10)
);
INSERT INTO Year_Month_Calendar
VALUES
('2015-01')
,('2015-02')
,('2015-03');
The inner select creates a table with all dates between the min and max date for each id.
SELECT Distinct_ID.id, Year_Month_Calendar.date
FROM Year_Month_Calendar
CROSS JOIN
( SELECT DISTINCT id FROM Table1 ) AS Distinct_ID
WHERE Year_Month_Calendar.date >= (SELECT MIN(date) FROM Table1 WHERE id=Distinct_ID.ID)
AND Year_Month_Calendar.date <= (SELECT MAX(date) FROM Table1 WHERE id=Distinct_ID.ID)
This is then LEFT JOINED to the original table to find the missing rows.
If you only want to return the missing row (my query displays the whole table to show how it works), add a WHERE clause to restrict the output to those rows where an id and date is not returned from Table1
Original answer before comments
You can do this without a tally table, since you say
Date range is: select distinct date from Table1
I've slightly changed the field names to avoid reserved words in SQL.
SELECT id_table.ID, date_table.`year_month`, table1.val
FROM (SELECT DISTINCT ID FROM table1) AS id_table
CROSS JOIN
(SELECT DISTINCT `year_month` FROM table1) AS date_table
LEFT JOIN table1
ON table1.ID=id_table.ID AND table1.`year_month` = date_table.`year_month`
ORDER BY id_table.ID
I've not filtered the results, in order to show how the query is working. To return the rows where only where a date is missing, add WHERE table1.year_month IS NULL to the outer query.
SQL Fiddle
You will need a tally table(s) or month/year tables. So you can then generate all of the potential combinations you want to test with. As far as exactly how to use it your example could use some expanding on such as last 12 months, last3 months, etc. but here is an example that might help you understand what you are looking for:
http://rextester.com/ZDQS5259
CREATE TABLE IF NOT EXISTS Tbl (
ID INTEGER
,Date VARCHAR(10)
,Value VARCHAR(10)
);
INSERT INTO Tbl VALUES
(1,'2015-01','val1')
,(1,'2015-02','val2')
,(2,'2015-01','val1')
,(2,'2015-03','val1');
SELECT yr.YearNumber, mn.MonthNumber, i.Id
FROM
(
SELECT 2016 as YearNumber
UNION SELECT 2015
) yr
CROSS JOIN (
SELECT 1 MonthNumber
UNION SELECT 2
UNION SELECT 3
UNION SELECT 4
UNION SELECT 5
UNION SELECT 6
UNION SELECT 7
UNION SELECT 8
UNION SELECT 9
UNION SELECT 10
UNION SELECT 11
UNION SELECT 12
) mn
CROSS JOIN (
SELECT DISTINCT ID
FROM
Tbl
) i
LEFT JOIN Tbl t
ON yr.YearNumber = CAST(LEFT(t.Date,4) as UNSIGNED)
AND mn.MonthNumber = CAST(RIGHT(t.Date,2) AS UNSIGNED)
AND i.ID = t.ID
WHERE
t.ID IS NULL
The basic idea to determine what you don't know is to generate all possible combinations of something could be. E.g. Year X Month X DISTINCT Id and then join back to figure out what is missing.
Probably not the prettiest but this should work.
select distinct c.ID, c.Date, d.Value
from (select a.ID, b.Date
from (select distinct ID from Table1) as a, (select distinct Date from Table1) as b) as c
left outer join Table1 d on (c.ID = d.ID and c.Date = d.Date)
where d.Value is NULL
I have SQL table (With more columns, but it is not important)
CREATE TABLE `test_results` (
`id` int AUTO_INCREMENT,
`date_time` datetime,
`altpn` varchar(60),
`error1` int,
`error2` int,
`error3` int,
PRIMARY KEY (`id`)
);
Data can be like: id, 2016-06-16 14:26:02, 9513 400, 590, 0, 0.
And on this table Im running this SQL query:
SELECT date(test_results.date_time) AS date, test_results.altpn as PN, COUNT(*) AS count
FROM test_results
WHERE (test_results.error1 = 1000 OR test_results.error1 = 1001 OR test_results.error2 = 1000 OR test_results.error2 = 1001 OR test_results.error3 = 1000 OR test_results.error3 = 1001)
GROUP BY date(test_results.date_time), test_results.altpn
ORDER BY date(test_results.date_time), test_results.altpn
This works OK, but I also need to know dates, when COUNT(*) is zero. I saw few topics about LEFT JOIN, but I am not able to modify codes to work with this table.
When you use WHERE, you filter rows with other error codes out and they cannot be counted. Instead, select all rows as usual and LEFT JOIN to a table where zero-rows do not exist:
SELECT *
FROM test_results t1
LEFT JOIN test_results t2 ON t2.id=t1.id
AND
(t2.error1 = 1000 OR t2.error1 = 1001 OR t2.error2 = 1000
OR t2.error2 = 1001 OR t2.error3 = 1000 OR t2.error3 = 1001)
As you see, the result set includes rows with errors of 1000/1001 and NULL values for other errors. Now, simply group and count them:
SELECT date(t1.date_time) AS date, t1.altpn as PN, COUNT(t2.id) AS count
FROM test_results t1
LEFT JOIN test_results t2 ON t2.id=t1.id
AND
(t2.error1 = 1000 OR t2.error1 = 1001 OR t2.error2 = 1000
OR t2.error2 = 1001 OR t2.error3 = 1000 OR t2.error3 = 1001)
GROUP BY date(t1.date_time), t1.altpn
ORDER BY date(t1.date_time), t1.altpn
http://sqlfiddle.com/#!9/9c6236/4
I have a table that contains two columns
ID | Name
----------------
1 | John
2 | Sam
3 | Peter
6 | Mike
It has missed IDs. In this case these are 4 and 5.
How do I find and insert them together with random names into this table?
Update: cursors and temp tables are not allowed. The random name should be 'Name_'+ some random number. Maybe it would be the specified value like 'Abby'. So it doesn't matter.
Using a recursive CTE you can determine the missing IDs as follows
DECLARE #Table TABLE(
ID INT,
Name VARCHAR(10)
)
INSERT INTO #Table VALUES (1, 'John'),(2, 'Sam'),(3,'Peter'),(6, 'Mike')
DECLARE #StartID INT,
#EndID INT
SELECT #StartID = MIN(ID),
#EndID = MAX(ID)
FROM #Table
;WITH IDS AS (
SELECT #StartID IDEntry
UNION ALL
SELECT IDEntry + 1
FROM IDS
WHERE IDEntry + 1 <= #EndID
)
SELECT IDS.IDEntry [ID]
FROM IDS LEFT JOIN
#Table t ON IDS.IDEntry = t.ID
WHERE t.ID IS NULL
OPTION (MAXRECURSION 0)
The option MAXRECURSION 0 will allow the code to avoid the recursion limit of SQL SERVER
From Query Hints and WITH common_table_expression (Transact-SQL)
MAXRECURSION number Specifies the maximum number of recursions
allowed for this query. number is a nonnegative integer between 0 and
32767. When 0 is specified, no limit is applied. If this option is not specified, the default limit for the server is 100.
When the specified or default number for MAXRECURSION limit is reached
during query execution, the query is ended and an error is returned.
Because of this error, all effects of the statement are rolled back.
If the statement is a SELECT statement, partial results or no results
may be returned. Any partial results returned may not include all rows
on recursion levels beyond the specified maximum recursion level.
Generating the RANDOM names will largly be affected by the requirements of such a name, and the column type of such a name. What exactly does this random name entail?
You can do this using a recursive Common Table Expression CTE. Here's an example how:
DECLARE #MaxId INT
SELECT #MaxId = MAX(ID) from MyTable
;WITH Numbers(Number) AS
(
SELECT 1
UNION ALL
SELECT Number + 1 FROM Numbers WHERE Number < #MaxId
)
SELECT n.Number, 'Random Name'
FROM Numbers n
LEFT OUTER JOIN MyTable t ON n.Number=t.ID
WHERE t.ID IS NULL
Here are a couple of articles about CTEs that will be helpful to Using Common Table Expressions and Recursive Queries Using Common Table Expressions
Start by selecting the highest number in the table (select top 1 id desc), or select max(id), then run a while loop to iterate from 1...max.
See this article about looping.
For each iteration, see if the row exists, and if not, insert into table, with that ID.
I think recursive CTE is a better solution, because it's going to be faster, but here is what worked for me:
IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[TestTable]') AND type in (N'U'))
DROP TABLE [dbo].[TestTable]
GO
CREATE TABLE [dbo].[TestTable](
[Id] [int] NOT NULL,
[Name] [varchar](50) NOT NULL,
CONSTRAINT [PK_TestTable] PRIMARY KEY CLUSTERED
(
[Id] ASC
))
GO
INSERT INTO [dbo].[TestTable]([Id],[Name]) VALUES (1, 'John')
INSERT INTO [dbo].[TestTable]([Id],[Name]) VALUES (2, 'Sam')
INSERT INTO [dbo].[TestTable]([Id],[Name]) VALUES (3, 'Peter')
INSERT INTO [dbo].[TestTable]([Id],[Name]) VALUES (6, 'Mike')
GO
declare #mod int
select #mod = MAX(number)+1 from master..spt_values where [type] = 'P'
INSERT INTO [dbo].[TestTable]
SELECT y.Id,'Name_' + cast(newid() as varchar(45)) Name from
(
SELECT TOP (select MAX(Id) from [dbo].[TestTable]) x.Id from
(
SELECT
t1.number*#mod + t2.number Id
FROM master..spt_values t1
CROSS JOIN master..spt_values t2
WHERE t1.[type] = 'P' and t2.[type] = 'P'
) x
WHERE x.Id > 0
ORDER BY x.Id
) y
LEFT JOIN [dbo].[TestTable] on [TestTable].Id = y.Id
where [TestTable].Id IS NULL
GO
select * from [dbo].[TestTable]
order by Id
GO
http://www.sqlfiddle.com/#!3/46c7b/18
It's actually very simple :
Create a table called #All_numbers which should contain all the natural number in the range that you are looking for.
#list is a table containing your data
select a.num as missing_number ,
'Random_Name' + convert(varchar, a.num)
from #All_numbers a left outer join #list l on a.num = l.Id
where l.id is null
These are the two tables I am looking at:
k3_alert_types
Type Description
0 No Show
1 Stop Arrival
2 ...
3 ...
4 ...
5 ...
k3_alert
Type
1
22
33
2
4
5
65
33
1
The tables are just examples, as the actual data sets are much larger. What I would like to do is find the mode of types in the k3_alert table, which I have done with the following:
SELECT TYPE , number_of_alerts
FROM
(
SELECT id, TYPE, COUNT(TYPE) AS number_of_alerts FROM k3_alert
GROUP BY TYPE
)t1
WHERE number_of_alerts IN
(
SELECT MAX( count_type ) FROM
(
SELECT id, TYPE , COUNT(TYPE ) AS count_type FROM k3_alert
GROUP BY TYPE
)t
)
I know how to join both tables:
SELECT k3_alert_types.description, k3_alert_types.type as type
FROM k3_alert_types
INNER JOIN k3_alert ON k3_alert_types.type = k3_alert.type
ORDER BY type
But I don't know how to do both at once.
I want to see this as the outcome of the whole process (just an example):
Description Type number_of_alerts
No Show 1 350
Any suggestions?
edit: Server type: MariaDB,
PHP extension: mysql
This should work:
SELECT at.description, at.type, COUNT(*) as number_of_alerts
FROM k3_alert_types at
INNER JOIN k3_alert a ON at.type = a.type
GROUP BY at.description, at.type
ORDER BY number_of_alerts DESC
LIMIT 1
So what I did was I used a CTE to store the value of mode and then selected top 1. If you wanted more flexibility or have a huge dataset you can use a temp table instead of a CTE.
Below is the code:
DECLARE #AlertType TABLE
(Type1 INT,
Descr varchar(20))
INSERT INTO #AlertType
(
Type1,
Descr
)
VALUES
( 1, 'Stop Arrival'),( 0,'No Show')
DECLARE #Alert TABLE
(Type1 INT)
INSERT INTO #Alert
(
Type1
)
VALUES (1),(0),(1),(23),(1),(5),(1)
;WITH CTE AS
(SELECT Type1, COUNT(*) AS number_of_alerts
FROM #Alert
GROUP BY Type1
)
SELECT TOP 1 AT.Descr, t1.Type1, t1.number_of_alerts
FROM CTE AS t1
JOIN #AlertType AS AT
ON AT.Type1 = t1.Type1
ORDER BY t1.number_of_alerts DESC