I am begginer to sql , need a help, how can i segregate the marks of a student only when the pass flag is Y . currently for learning purpose , i have created a table and added 3 columns with two Y flag and one N flag. The query should only return sum of mark only when all the flag is Y.
Can someone help .
Thanks,
You can use a HAVING clause and conditional aggregation:
SELECT name,
SUM(marks)
FROM table_name
GROUP BY name
HAVING COUNT(CASE WHEN pass = 'N' THEN 1 END) = 0
Which, for the sample data:
CREATE TABLE table_name (
name VARCHAR(10),
marks NUMERIC,
pass VARCHAR(1)
);
INSERT INTO table_name (name, marks, pass)
SELECT 'xxx', 50, 'Y' UNION ALL
SELECT 'xxx', 50, 'Y' UNION ALL
SELECT 'zzz', 50, 'N';
Outputs the "sum of mark only when all the flag is Y.":
name
SUM(marks)
xxx
100
db<>fiddle here
Related
So i have a union query like:
select count(id)
from table 1
where membernumber = 'x'
and castnumber = 'y'
union
select count(id)
from table 1
where membernumber = 'x'
and castnumber = 'y'
union
etc...
There will be over 200 unions coming from a list 2x 200 table with values for x and y in each row. So each union query has to get the value of x and y from the corresponding row (not in any particular order).
How can i achieve that ?
Thanks
Try this:
DECLARE GLOBAL TEMPORARY TABLE
SESSION.PARAMETERS
(
MEMBERNUMBER INT
, CASTNUMBER INT
) DEFINITION ONLY WITH REPLACE
ON COMMIT PRESERVE ROWS NOT LOGGED;
-- Insert all the the constants in your application with
INSERT INTO SESSION.PARAMETERS
(MEMBERNUMBER, CASTNUMBER)
VALUES (?, ?);
-- I don't know the meaning of the result you want to get
-- but it's equivalent
select distinct count(t.id)
from table1 t
join session.parameters p
on p.membernumber = t.membernumber
and p.castnumber = t.castnumber
group by t.membernumber, t.castnumber;
example:
there is a json array column(type:string) from a hive table like:
"[{"filed":"name", "value":"alice"}, {"filed":"age", "value":"14"}......]"
how to convert it into :
name age
alice 14
by hive sql?
I've tried lateral view explode but it's not working.
thanks a lot!
This is working example of how it can be parsed in Hive. Customize it yourself and debug on real data, see comments in the code:
with your_table as (
select stack(1,
1,
'[{"field":"name", "value":"alice"}, {"field":"age", "value":"14"}, {"field":"something_else", "value":"somevalue"}]'
) as (id,str) --one row table with id and string with json. Use your table instead of this example
)
select id,
max(case when field_map['field'] = 'name' then field_map['value'] end) as name,
max(case when field_map['field'] = 'age' then field_map['value'] end) as age --do the same for all fields
from
(
select t.id,
t.str as original_string,
str_to_map(regexp_replace(regexp_replace(trim(a.field),', +',','),'\\{|\\}|"','')) field_map --remove extra characters and convert to map
from your_table t
lateral view outer explode(split(regexp_replace(regexp_replace(str,'\\[|\\]',''),'\\},','}|'),'\\|')) a as field --remove [], replace "}," with '}|" and explode
) s
group by id --aggregate in single row
;
Result:
OK
id name age
1 alice 14
One more approach using get_json_object:
with your_table as (
select stack(1,
1,
'[{"field":"name", "value":"alice"}, {"field":"age", "value":"14"}, {"field":"something_else", "value":"somevalue"}]'
) as (id,str) --one row table with id and string with json. Use your table instead of this example
)
select id,
max(case when field = 'name' then value end) as name,
max(case when field = 'age' then value end) as age --do the same for all fields
from
(
select t.id,
get_json_object(trim(a.field),'$.field') field,
get_json_object(trim(a.field),'$.value') value
from your_table t
lateral view outer explode(split(regexp_replace(regexp_replace(str,'\\[|\\]',''),'\\},','}|'),'\\|')) a as field --remove [], replace "}," with '}|" and explode
) s
group by id --aggregate in single row
;
Result:
OK
id name age
1 alice 14
I have a situation here, I have a table with a flag assigned to the column names(like 'Y' or 'N'). I have to select the column names of a row, if it have a specific value.
My Table:
Name|sub-1|sub-2|sub-3|sub-4|sub-5|sub-6|
-----------------------------------------
Tom | Y | | Y | Y | | Y |
Jim | Y | Y | | | Y | Y |
Ram | | Y | | Y | Y | |
So I need to get, what are all the subs are have 'Y' flag for a particular Name.
For Example:
If I select Tom I need to get the list of 'Y' column name in query output.
Subs
____
sub-1
sub-3
sub-4
sub-6
Your help is much appreciated.
The problem is that your database model is not normalized. If it was properly normalized the query would be easy. So the workaround is to normalize the model "on-the-fly" to be able to make the query:
select col_name
from (
select name, sub_1 as val, 'sub_1' as col_name
from the_table
union all
select name, sub_2, 'sub_2'
from the_table
union all
select name, sub_3, 'sub_3'
from the_table
union all
select name, sub_4, 'sub_4'
from the_table
union all
select name, sub_5, 'sub_5'
from the_table
union all
select name, sub_6, 'sub_6'
from the_table
) t
where name = 'Tom'
and val = 'Y'
The above is standard SQL and should work on any (relational) DBMS.
Below code works for me.
select t.Subs from (select name, u.subs,u.val
from TableName s
unpivot
(
val
for subs in (sub-1, sub-2, sub-3,sub-4,sub-5,sub-6,sub-7)
) u where u.val='Y') T
where t.name='Tom'
Somehow I am near to the solution. I can get for all rows. (I just used 2 columns)
select col from ( select col, case s.col when 'sub-1' then sub-1 when 'sub-2' then sub-2 end AS val from mytable cross join ( select 'sub-1' AS col union all select 'sub-2' ) s ) s where val ='Y'
It gives the columns for all row. I need the same data for a single row. Like if I select "Tom", I need the column names for 'Y' value.
I'm answering this under a few assumptions here. The first is that you KNOW the names of the columns of the table in question. Second, that this is SQL Server. Oracle and MySql have ways of performing this, but I don't know the syntax for that.
Anyways, what I'd do is perform an 'UNPIVOT' on the data.
There's a lot of parans there, so to explain. The actual 'unpivot' statement (aliased as UNPVT) takes the data and twists the columns into rows, and the SELECT associated with it provides the data that is being returned. Here's I used the 'Name', and placed the column names under the 'Subs' column and the corresponding value into the 'Val' column. To be precise, I'm talking about this aspect of the above code:
SELECT [Name], [Subs], [Val]
FROM
(SELECT [Name], [Sub-1], [Sub-2], [Sub-3], [Sub-4], [Sub-5], [Sub-6]
FROM pvt) p
UNPIVOT
(Orders FOR [Name] IN
([Name], [Sub-1], [Sub-2], [Sub-3], [Sub-4], [Sub-5], [Sub-6])
)AS unpvt
My next step was to make that a 'sub-select' where I could find the specific name and val that was being hunted for. That would leave you with a SQL Statement that looks something along these lines
SELECT [Name], [Subs], [Val]
FROM (
SELECT [Name], [Subs], [Val]
FROM
(SELECT [Name], [Sub-1], [Sub-2], [Sub-3], [Sub-4], [Sub-5], [Sub-6]
FROM pvt) p
UNPIVOT
(Orders FOR [Name] IN
([Name], [Sub-1], [Sub-2], [Sub-3], [Sub-4], [Sub-5], [Sub-6])
)AS unpvt
) AS pp
WHERE 1 = 1
AND pp.[Val] = 'Y'
AND pp.[Name] = 'Tom'
select col from (
select col,
case s.col
when 'sub-1' then sub-1
when 'sub-2' then sub-2
when 'sub-3' then sub-3
when 'sub-4' then sub-4
when 'sub-5' then sub-5
when 'sub-6' then sub-6
end AS val
from mytable
cross join
(
select 'sub-1' AS col union all
select 'sub-2' union all
select 'sub-3' union all
select 'sub-4' union all
select 'sub-5' union all
select 'sub-6'
) s on name="Tom"
) s
where val ='Y'
included the join condition as
on name="Tom"
I have data in a table which looks like:
I want to split its data and make it look like the following through a sql query in Oracle (without using pivot):
How can it be done?? is there any other way of doing so without using pivot?
You need to use a pivot query here to get the output you want:
SELECT Name,
MIN(CASE WHEN ID_Type = 'PAN' THEN ID_No ELSE NULL END) AS PAN,
MIN(CASE WHEN ID_Type = 'DL' THEN ID_No ELSE NULL END) AS DL,
MIN(CASE WHEN ID_Type = 'Passport' THEN ID_No ELSE NULL END) AS Passport
FROM yourTable
GROUP BY Name
You could also try using Oracle's built in PIVOT() function if you are running version 11g or later.
Since you mention without using PIVOT function, you can try to
use SQL within group for moving rows onto one line and listagg to display multiple column values in a single column.
In Oracle 11g, we can use the listagg built-in function :
select
deptno,
listagg (ename, ',')
WITHIN GROUP
(ORDER BY ename) enames
FROM
emp
GROUP BY
deptno
Which should give you the below result:
DEPTNO ENAMES
------ --------------------------------------------------
10 CLARK,KING,MILLER
20 ADAMS,FORD,JONES,SCOTT,SMITH
30 ALLEN,BLAKE,JAMES,MARTIN,TURNER,WARD
You can find all the solution(s) to this problem here:
http://www.dba-oracle.com/t_converting_rows_columns.htm
For Oracle 11g and above, you could use PIVOT.
For pre-11g release, you could use MAX and CASE.
A common misconception, about PIVOT better in terms of performance than the old way of MAX and DECODE. But, under the hood PIVOT is same MAX + CASE. You can check it in 12c where Oracle added EXPAND_SQL_TEXT procedure to DBMS_UTILITY package.
For example,
SQL> variable c clob
SQL> begin
2 dbms_utility.expand_sql_text(Q'[with choice_tbl as (
3 select 'Jones' person,1 choice_nbr,'Yellow' color from dual union all
4 select 'Jones',2,'Green' from dual union all
5 select 'Jones',3,'Blue' from dual union all
6 select 'Smith',1,'Orange' from dual
7 )
8 select *
9 from choice_tbl
10 pivot(
11 max(color)
12 for choice_nbr in (1 choice_nbr1,2 choice_nbr2,3 choice_nbr3)
13 )]',:c);
14 end;
15 /
PL/SQL procedure successfully completed.
Now let's see what Oracle actually does internally:
SQL> set long 100000
SQL> print c
C
--------------------------------------------------------------------------------
SELECT "A1"."PERSON" "PERSON",
"A1"."CHOICE_NBR1" "CHOICE_NBR1",
"A1"."CHOICE_NBR2" "CHOICE_NBR2",
"A1"."CHOICE_NBR3" "CHOICE_NBR3"
FROM (
SELECT "A2"."PERSON" "PERSON",
MAX(CASE WHEN ("A2"."CHOICE_NBR"=1) THEN "A2"."COLOR" END ) "CHOICE_NBR1",
MAX(CASE WHEN ("A2"."CHOICE_NBR"=2) THEN "A2"."COLOR" END ) "CHOICE_NBR2",
MAX(CASE WHEN ("A2"."CHOICE_NBR"=3) THEN "A2"."COLOR" END ) "CHOICE_NBR3"
FROM (
(SELECT 'Jones' "PERSON",1 "CHOICE_NBR",'Yellow' "COLOR" FROM "SYS"."DUAL" "A7") UNION ALL
(SELECT 'Jones' "'JONES'",2 "2",'Green' "'GREEN'" FROM "SYS"."DUAL" "A6") UNION ALL
(SELECT 'Jones' "'JONES'",3 "3",'Blue' "'BLUE'" FROM "SYS"."DUAL" "A5") UNION ALL
(SELECT 'Smith' "'SMITH'",1 "1",'Orange' "'ORANGE'" FROM "SYS"."DUAL" "A4")
) "A2"
GROUP BY "A2"."PERSON"
) "A1"
SQL>
Oracle internally interprets the PIVOT as MAX + CASE.
You're able to create a non-pivot query by understanding what the pivot query will do:
select *
from yourTable
pivot
(
max (id_no)
for (id_type) in ('PAN' as pan, 'DL' as dl, 'Passport' as passport)
)
What the pivot does is GROUP BY all columns not specified inside the PIVOT clause (actually, just the name column), selecting new columns in a subquery fashion based on the aggregations before the FOR clause for each value specified inside the IN clause and discarding those columns specified inside the PIVOT clause.
When I say "subquery fashion" I'm refering to one way to achieve the result got with PIVOT. Actually, I don't know how this works behind the scenes. This subquery fashion would be like this:
select <aggregation>
from <yourTable>
where 1=1
and <FORclauseColumns> = <INclauseValue>
and <subqueryTableColumns> = <PIVOTgroupedColumns>
Now you identified how you can create a query without the PIVOT clause:
select
name,
(select max(id_no) from yourTable where name = t.name and id_type = 'PAN') as pan,
(select max(id_no) from yourTable where name = t.name and id_type = 'DL') as dl,
(select max(id_no) from yourTable where name = t.name and id_type = 'Passport') as passport
from yourTable t
group by name
You can use CTE's to break the data down and then join them back together to get what you want:
WITH NAMES AS (SELECT DISTINCT NAME
FROM YOURTABLE),
PAN AS (SELECT NAME, ID_NO AS PAN
FROM YOURTABLE
WHERE ID_TYPE = 'PAN'),
DL AS (SELECT NAME, ID_NO AS DL
FROM YOURTABLE
WHERE ID_TYPE = 'DL'),
PASSPORT AS (SELECT NAME, ID_NO AS "Passport"
FROM YOURTABLE
WHERE ID_TYPE = 'Passport')
SELECT n.NAME, p.PAN, d.DL, t."Passport"
FROM NAMES n
LEFT OUTER JOIN PAN p
ON p.NAME = n.NAME
LEFT OUTER JOIN DL d
ON d.NAME = p.NAME
LEFT OUTER JOIN PASSPORT t
ON t.NAME = p.NAME'
Replace YOURTABLE with the actual name of your table of interest.
Best of luck.
I have 5 random names each for male and female. I need to insert random names based on the gender. But how can we insert names in random from a set of 5 names in SQL. Is it possible?
select name from table order by newid()
Create a table with the names, and an integer ID. Then use RAND() with % 5 to get down to a value between 0 and 4 inclusively. Add 1 if you want a male, and 6 if you want a female. Like so:
Create table RandomNames
(id int,
name varchar(100),
gender char(1)
)
insert into RandomNames
(id, name,gender)
select 1,'Bill','M'
union
select 2,'John','M'
union
select 3,'Steve','M'
union
select 4,'Mike','M'
union
select 5,'Phil','M'
union
select 6,'Sarah','F'
union
select 7,'Ann','F'
union
select 8,'Marie','F'
union
select 9,'Liz','F'
union
select 10,'Stephanie','F'
declare #wantedGender char(1)
select #wantedGender = 'M'
select name
from RandomNames
where id = (CAST(RAND()*100 as int) % 5) + case when #wantedGender = 'M' then 1 else 6 end
Store the 5 random names for male in one table and the 5 random names for female in another table. Select a random integer between 1 and 5 and cross reference to male or female table using an inner join.
Create a function
CREATE FUNCTION [dbo].[getRandomName](#gen varchar(10))
RETURNS #name varchar(50)
AS
BEGIN
SELECT TOP 1 #name = name FROM table WHERE gender=#gen ORDER BY newid()
END
Then, just pass #gen to the function like this
select dbo.getRandomName('male')
Or, update many rows like this:
UPDATE myNewTable
SET newName=dbo.getRandomName('male')
WHERE gender='male'
In SQL Server, the best way to get "random" is to use newid(). You can sort by this to get a sorted list.
If you have five names for each gender, you can use a CTE to store them. The insert would then look like:
with names as (
select 'M' as gender, 'Alexander' as name union all
select 'M', 'Burt' union all
select 'M', 'Christopher' union all
select 'M', 'Daniel' union all
select 'M', 'Eric' union all
select 'F', 'Alexandra' union all
select 'F', 'Bertha' union all
select 'F', 'Christine' union all
select 'F', 'Daniela' union all
select 'F', 'Erica'
)
insert into table(name)
select top 1 name
from names
where gender = #MyGender
order by newid();
select top 1 name from RandomNames
where gender = 'M' order by newid()
Sample fiddle