I have the following query
select a.empid, a.age, a.city, b.name
join supervisor b on a.supervisorid = b.empid
There is a chance that entries in "Supervisor" table may not be present in "Employee" table as an Employee
After forming the above query , i want to make "b.supervisorname" field as "null", if "b.supervisorid" not in "a.empid" column
EMPLOYEE TABLE:
EMPID--AGE--CITY--SUPERVISOR
1--12--A--123
2--21--B--1
3--23--C--2
Supervisor Table:
SUPERVISOR TABLE
EMPID--NAME
123--ABC
1--EFG
2-HIJ
OUTPUT:
EMPID--AGE--CITY--NAME
1--12--A--null
2--21--B--ABC
3--23--C--EFG
i dont want to use,
select a.empid, a.age, a.city, b.name
from employee a
join supervisor b on a.supervisorid =
(select empid
from supervisor
where empid in (select empid from employee))
as this kind of querying affects the performance
Is there any shortcut way to do it?
You should ALWAYS use explicit joins to avoid performance issues. And in general it helps to define a FROM clause in queries
The query below should work for you:
select
e.empid,
e.age,
e.city,
s.name
FROM
employee e
LEFT OUTER JOIN
supervisor s
on e.supervisor = s.empid
Related
I have 2 tables.
This is tableA
(invoice,D/O, cost..) and
Table B
(D/O, GRN, Qty)
Now how to use query to show table A include GRN,Qty
See
You need a LEFT OUTER JOIN to retrieve all the records from table A with matched records from table B.
Guessing at the join criteria because your question doesn't say what they are:
select a.*
, b.grn
, b.grn_line
, b.qty_grn
from a
left outer join b
on a.do = b.do
and a.do_line = b.do_line
and a.invoice_line = b.grn_line
I was just wondering how you select multiple records from a table column. Please see below the query.
SELECT DISTINCT DEPARTMENT_NAME, CITY, COUNTRY_NAME
FROM OEHR_DEPARTMENTS
NATURAL JOIN OEHR_EMPLOYEES
NATURAL JOIN OEHR_LOCATIONS
NATURAL JOIN OEHR_COUNTRIES
WHERE JOB_ID = 'SA_MAN' AND JOB_ID = 'SA_REP'
;
Basically, I want to be able to select records from the table column I have, however when you use AND it only displays SA_MAN and not SA_REP. I have also tried to use OR and it displays no rows selected. How would I actually be able to select both Job ID's without it just displaying one or the other.
Sorry this may sound like a stupid question (and probably not worded right), but I am pretty new to Oracle 11g SQL.
For your own comfort while debugging, I suggest you to use inner joins instead of natual joins.
That where clause is confusing, if not utterly wrong, because you don't make clear which tables' JOB_ID should be filtered. Use inner joins, give aliases to tables, and refer to those aliases in the where clause.
select distinct DEPARTMENT_NAME, CITY, COUNTRY_NAME
from OEHR_DEPARTMENTS t1
join OEHR_EMPLOYEES t2
on ...
join OEHR_LOCATIONS t3
on ...
join OEHR_COUNTRIES t4
on ...
where tn.JOB_ID = 'SA_MAN' AND tm.JOB_ID = 'SA_REP'
After rephrasing your query somehow like this, you'll have a clearer view on the logical operator you'll have to use in the where clause, which I bet will be an OR.
EDIT (after more details were given)
To list the departments that employ staff with both 'SA_MAN' and 'SA_REP' job_id, you have to join the departments table with the employees twice, once with the filter job_id='SA_MAN' and once with job_id='SA_REP'
select distinct DEPARTMENT_NAME, CITY, COUNTRY_NAME
from OEHR_DEPARTMENTS t1
join OEHR_EMPLOYEES t2
on t1.department_id = t2.department_id --guessing column names
join OEHR_EMPLOYEES t3
on t1.department_id = t3.department_id --guessing column names
join OEHR_LOCATIONS t4
on t1.location_id = t4.location_id --guessing column names
join OEHR_COUNTRIES t5
on t4.country_id = t5.country_id --guessing column names
where t2.job_id = 'SA_MAN' and t3.job_id = 'SA_REP'
order by 1, 2, 3
We have tried the below query in hive. but getting the error. please help me to resolve this in any other way.
select count(1) as OpenItems from issues i , issue_statuses s
where s.id = i.status_id
and s.name NOT IN ('Closed','Passed','Rejected','On
Hold','Baselined','Completed')
and i.project_id IN
(select id from projects3 from
CASE WHEN ${projectname} = 'All' then id in
(select p.id from members m, projects3 p ,users_1 u
where m.project_id = p.id and u.id = m.user_id and u.status = '1'
and u.id IN
(select u1.id from users_1 u1, Supervisor_hierarchy s1 where u1.mail = s1.email and s1.name = ${Superisorname})
group by p.id)
WHEN (${projectname} <>'All' and ${SubProject projectname} ='All') then id
IN (select id from (select id from project_closure where parent_id in (select id from projects where name = ${projectname}) group by id)a)
WHEN (${SubProject projectname}<>'All' and ${projectname}<> 'All') then id
IN (select id from(select id from project_closure where id in (select id from projects where name = ${SubProject projectname}) group by id)a)
END
order by id)
error: 6:5 Unsupported SubQuery Expression 'id': SubQuery expression refers to both Parent and SubQuery expressions and is not a valid join condition.
I know it is late but posting for anyone who face this issue.
This issue occurs when we encounter one or more of the below limitations of Hive Subqueries.
In this scenario, the reference to the parent query is used in Group By clause which comes under the 4th limitation.
Hive Subquery Limitations
These subqueries are only supported on the right-hand side of an expression.
IN/NOT IN subqueries may only select a single column.
EXISTS/NOT EXISTS must have one or more correlated predicates.
References to the parent query are only supported in the WHERE clause of the subquery.
Source: https://cwiki.apache.org/confluence/display/Hive/LanguageManual+SubQueries
I have a table something like this:
ID|Value
01|1
02|4
03|12
01|5
02|14
03|22
01|9
02|32
02|62
01|13
03|92
I want to know how much progress have each id made (from initial or minimal value)
so in sybase I can type:
select ID, (value-min(value)) from table group by id;
ID|Value
01|0
01|4
01|8
01|12
02|0
02|10
02|28
02|58
03|0
03|10
03|80
But monetdb does not support this (I am not sure may be cz it uses SQL'99).
Group by only gives one column or may be average of other values but not the desired result.
Are there any alternative to group by in monetdb?
You can achieve this with a self join. The idea is that you build a subselect that gives you the minimum value for each id, and then join that to the original table by id.
SELECT a.id, a.value-b.min_value
FROM "table" a INNER JOIN
(SELECT id, MIN(value) AS min_value FROM "table" GROUP BY id) AS b
ON a.id = b.id;
am a newbie to Oracle/PL SQL.I've 2 tables A and B.
A has a column CustId,Age,Location and Date. Table B has 2 columns CustId,CustName.
What would be the sql query to show show CustName and Location for a given age?
Thanks.
your question "What would be the sql query to show show CustName and Location for a given age?" helps define your query pretty well:
SELECT CustName, Location
FROM TableA a
INNER JOIN TableB b
ON b.CustId = a.CustId
WHERE a.Age = #
All we need to do on top of that select for your specific fields is make sure to join the two tables on their common column (CustID).
Another option would be to avoid the WHERE statement:
SELECT CustName, Location
FROM TableB b
INNER JOIN TableA a
ON a.CustID = b.CustID
AND a.Age = #
you need join. something like
SELECT custname, location FROM a JOIN b ON a.custid = b.custid WHERE age = [age];