some sample data:
Id name value ref
1 ab xy
2 aba z
3 ab xy
4 abc def
5 gxr mdy
what I am trying to do is to get the two column that appeared more than once
so row 1 and row 3 would be selected.
select name, value from table_x
where value is not null group by name having count(name) >= 2
and having count(value) >= 2;
got stucked.....
#vkp's answer is correct if you only care about finding the distinct name/value pairs that appear more than once. But if you actually want the individual rows that satisfy the criteria, try this:
SELECT t1.Name, t1.[Value]
FROM Table_X t1
JOIN
(
SELECT Name, [Value]
FROM Table_X
where [Value] IS NOT NULL
GROUP BY Name, [Value]
HAVING COUNT(1) >= 2
) t2 ON t1.Name = t2.Name AND t1.[Value] = t2.[Value]
Your syntax is incorrect. group by name and value and check for count >=2 thereafter.
select name, value
from table_x
where value is not null
group by name, value
having count(*) >= 2;
Related
I have a result set
name stage value
---- ----- -----
jim 1 4
jim 1 8
paul 1 8
paul 1 8
want to remove the rows where 8 is the only value against a person
keep the 2 jim rows and lose the 2 paul rows
You can use not exists. For a select query:
select t.*
from t
where not exists (select 1
from t t2
where t2.name = t.name and t2.value = 8
);
Similar logic (except using exists rather than not exists) can be used for a delete -- if you really want to delete the rows from the table.
If you have a complex query that you don't want to repeat, then window functions are helpful:
select t.*
from (select t.*,
sum(case when value = 8 then 1 else 0 end) over (partition by name) as cnt_8
from t
) t
where cnt_8 = 0;
If your database support analytical function then you can use count as follows:
Select * from
(Select t.*,
Count(case when value <> 8 then 1 end) over (partition by name) as cnt
From your_table t) t
Where cnt > 0
Assuming you also have an ID column (defined as an auto increment integer) defined in your table this query would select the row with the highest id for each unique combination:
select max(id) from t group by name,stage,value
In your example this would only return the latest id for rows having values paul,1,8 in columns name,stage,value respectively.
You can then use the prior query to filter out any duplciates using it in the where clause:
select * from t
where id in (select max(id) from t group by name,stage,value)
Finally you can also delete rows that are not unique if that's your goal:
delete from t
where not id in (select max(id) from t group by name,stage,value)
age | name | course | score
_________________________
10 |James | Math | 10
10 |James | Lab | 15
12 |Oliver | Math | 15
13 |William | Lab | 13
I want select record where math >= 10 and lab >11
I write this query
select * from mytable
where (course='Math' and score>10) and (course='Lab' and score>11)
but this query does not return any record.
I want this result
age | name
____________
10 |James
where condition (math >= 10 and lab >11) is dynamically generate and perhaps has 2 condition or 100 or more...
please help me
You query looks for records that satisfy both conditions at once - which cannot happen, since each record has a single course.
You want a condition that applies across rows having the same name, so this suggest aggregation instead:
select age, name
from mytable
where course in ('Math', 'Lab')
group by age, name
having
max(case when course = 'Math' then score end) > 10
and max(case when course = 'Lab' then score end) > 11
If you want the names, then use aggregation and a having clause:
select name, age
from mytable
where (course = 'Math' and score > 10) or
(course = 'Lab' and score > 11)
group by name, age
having count(distinct course) = 2;
If you want the detailed records, use window functions:
select t.*
from (select t.*,
(dense_rank() over (partition by name, age order by course asc) +
dense_rank() over (partition by name, age order by course desc)
) as cnt_unique_courses
from mytable t
where (course = 'Math' and score > 10) or
(course = 'Lab' and score > 11)
) t
where cnt_unique_courses = 2;
SQL Server doesn't support count(distinct) as a window function. But you can implement it by using dense_rank() twice.
If you formulate the problem as:
Select all unique (name, age) combinations
That have a row for course Math with a score >= 10
And that have a row for course Lab with a score > 11
Then you can translate this to something very similar in SQL:
select distinct t1.age, t1.name -- unique combinations
from mytable t1
where exists ( select top 1 'x' -- with a row math score >= 10
from mytable t2
where t2.name = t1.name
and t2.age = t1.age
and t2.course = 'math'
and t2.score >= 10 )
and exists ( select top 1 'x' -- with a row lab score > 11
from mytable t3
where t3.name = t1.name
and t3.age = t1.age
and t3.course = 'lab'
and t3.score > 11 );
i think either your data or your condition is not right to get your output. though based on your condition you can separately used your condition and then use Intersect from both selection and get your filtered data. like the code below.
select Age,Name
from Table_1
where Course ='Math' and Score>=10
INTERSECT
select Age,Name
from Table_1
where Course ='Lab' and Score>11
You can write query using co-related subquery
select * from table_1 t1
where score >11 and course ='lab'
and [name] in (select [name] from table_1 t2 where t1.[name] =t2.[name] and t1.age =t2.Age
and t2.Score >=10 and course = 'Math')
I have a following table with following data:
Table
Now I want to get all those users (distinct only) who do not have value 5 in Column B. What I mean is user1 has a value 5 in some row, then all user 1 rows are dismissed.
Following result should be produced:
user2 (because value is null)
user3 (no value 5)
How can I do that?
Perhaps the easiest way to do this would be aggregation by user:
SELECT ColumnA
FROM yourTable
GROUP BY ColumnA
HAVING COUNT(CASE WHEN ColumnB = 5 THEN 1 END) = 0;
One method is aggregation:
select columnA
from t
group by columnA
having sum(case when columnB = 5 then 1 else 0 end) = 0;
You can do this by Minus operator
SELECT distinct colA
FROM have
WHERE colB not in(5)
MINUS
SELECT distinct colA
FROM have
WHERE colB=5;
Using NOT EXISTS you can able to get the result
SELECT DISTINCT T1.ColumnA
FROM TableName T1
WHERE NOT EXISTS (
SELECT * FROM TableName T2 WHERE T2.ColumnA = T1.ColumnA AND T2.ColumnB <> 5
)
One more way -
SELECT DISTINCT T1.ColumnA
FROM TableName T1
WHERE T1.ColumnA NOT IN
(
SELECT T2.ColumnA FROM TableName T2 WHERE T2.ColumnB = 5
)
I have a few tables in my DB. Let's call them table1, table2, table3.
All of them have a column named value.
I need to create a query that will return a single number, where this number is the sum of all the value columns from all the tables together...
I've tried the following way:
SELECT (SELECT SUM(value) FROM table1) + (SELECT SUM(value) FROM table2) + (SELECT SUM(value) FROM table3) as total_sum
But when at least one of the inner SUM is NULL, the entire total value (total_sum here) is NULL, so that's not very trustworthy.
When there is no value in a certain inner SUM query, I need it to return 0, so it doesn't affect the rest of the SUM.
To make it more clear, let's say I have the following 2 tables:
TABLE1:
ID | NAME | VALUE
1 Name1 1000
2 Name2 2000
3 Name3 3000
TABLE2:
ID | NAME | VALUE
1 Name1 1500
2 Name2 2500
3 Name3 3500
Eventually, the query I need will return a single value - 13500, which is the total sum of all the values under the VALUE column of all the tables here.
All the other columns have no meaning for the needed query, and I even don't care much for performance in this case.
You can achieve it using Coalesce as follows
SELECT
(SELECT coalesce(SUM(value),0) FROM table1) +
(SELECT coalesce(SUM(value),0) FROM table2) +
(SELECT coalesce(SUM(value),0) FROM table3) as total_sum
Another approach is to use union all to merge all values into single table
select distinct coalesce(sum(a.value), 0) as total_sum from
(select value from table1
union all
select value from table 2
union all
select value from table 3) a;
You can use the ISNULL function to take care of the NULLs.
SELECT ISNULL((
SELECT SUM(value) FROM table1
)
, 0
) + ISNULL((
SELECT SUM(value) FROM table2
)
, 0
) + ISNULL((
SELECT SUM(value) FROM table3
)
, 0
) AS total_sum;
You could simply sum all of them:
select sum(total) as Total
from (
select sum(value) as total from Table1
union all
select sum(value) as total from Table2
union all
select sum(value) as total from Table3
) t;
I'm currently having trouble writing the business logic to get rows from a table with id's and a flag which I have appended to it.
For example,
id: id seq num: flag: Date:
A 1 N ..
A 2 N ..
A 3 N
A 4 Y
B 1 N
B 2 Y
B 3 N
C 1 N
C 2 N
The end result I'm trying to achieve is that:
For each unique ID I just want to retrieve one row with the condition for that row being that
If the flag was a "Y" then return that row.
Else return the last "N" row.
Another thing to note is that the 'Y' flag is not always necessarily the last
I've been trying to get a case condition using a partition like
OVER (PARTITION BY A."ID" ORDER BY A."Seq num") but so far no luck.
-- EDIT:
From the table, the sample result would be:
id: id seq num: flag: date:
A 4 Y ..
B 2 Y ..
C 2 N ..
Using a window clause is the right idea. You should partition the results by the ID (as you've done), and order them so the Y flag rows come first, then all the N flag rows in descending date order, and pick the first for each id:
SELECT id, id_seq_num, flag, date
FROM (SELECT id, id_seq_num, flag, date,
ROW_NUMBER() OVER (PARTITION BY id
ORDER BY CASE flag WHEN 'Y' THEN 0
ELSE 1
END ASC,
date ASC) AS rk
FROM mytable) t
WHERE rk = 1
My approach is to take a UNION of two queries. The first query simply selects all Yes records, assuming that Yes only appears once per ID group. The second query targets only those ID having no Yes anywhere. For those records, we use the row number to select the most recent No record.
WITH cte1 AS (
SELECT id
FROM yourTable
GROUP BY id
HAVING SUM(CASE WHEN flag = 'Y' THEN 1 ELSE 0 END) = 0
),
cte2 AS (
SELECT *,
ROW_NUMBER() OVER (PARTITION BY t1.id ORDER BY t1."id seq" DESC) rn
FROM yourTable t1
INNER JOIN cte1 t2
ON t1.id = t2.id
)
SELECT *
FROM yourTable
WHERE flag = 'Y'
UNION ALL
SELECT *
FROM cte2 t2
WHERE t2.rn = 1
Here's one way (with quite generic SQL):
select t1.*
from Table1 as t1
where t1.id_seq_num = COALESCE(
(select max(id_seq_num) from Table1 as T2 where t1.id = t2.id and t2.flag = 'Y') ,
(select max(id_seq_num) from Table1 as T3 where t1.id = t3.id and t3.flag = 'N') )
Available in a fiddle here: http://sqlfiddle.com/#!9/5f7f9/6
SELECT DISTINCT id, flag
FROM yourTable