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
Related
Anyone please help me, how to uniqe each row
SELECT T3.ID_JS,T5.DIVISI_AREA,T4.NAME_METHODE_REPAIR, T1.URUTAN AS SORT, TO_DATE(T1.TIME_FINISHED_WORK,'DD/MM/YYYY') AS DATE_FINISHED
FROM TB_WORK T1
JOIN TB_INSPECTION T2 ON T1.ID_INSPECTION=T2.ID_INSPECTION
JOIN TB_JOBSHEET T3 ON T2.ID_JS = T3.ID_JS
JOIN TB_METHODE_REPAIR T4 ON T1.ID_METHODE_REPAIR=T4.ID_METHODE_REPAIR
JOIN TB_DIVISI T5 ON T1.ID_DIVISI=T5.ID_DIVISI
where t3.id_js=142414
GROUP BY T3.ID_JS,T5.DIVISI_AREA,T4.NAME_METHODE_REPAIR, T1.URUTAN,TO_DATE(T1.TIME_FINISHED_WORK,'DD/MM/YYYY')
ORDER BY T3.ID_JS, TO_DATE(T1.TIME_FINISHED_WORK,'DD/MM/YYYY') desc
[Result] (http://prntscr.com/sfpuuq)
Those rows are unique, so I'll guess: there are two rows with sort = 3 and you'd want to have only one. If that's so, regarding the fact that date value is the only thing that makes difference, a simple way is to use aggregate function (such as min or max). I used max, but you can change it if you want:
SELECT t3.id_js,
t5.divisi_area,
t4.name_methode_repair,
t1.urutan AS sort,
MAX (TO_DATE (t1.time_finished_work, 'DD/MM/YYYY')) AS date_finished
FROM tb_work t1
JOIN tb_inspection t2 ON t1.id_inspection = t2.id_inspection
JOIN tb_jobsheet t3 ON t2.id_js = t3.id_js
JOIN tb_methode_repair t4
ON t1.id_methode_repair = t4.id_methode_repair
JOIN tb_divisi t5 ON t1.id_divisi = t5.id_divisi
WHERE t3.id_js = 142414
GROUP BY t3.id_js,
t5.divisi_area,
t4.name_methode_repair,
t1.urutan
ORDER BY t3.id_js, date_finished DESC
You'd remove date column from GROUP BY; besides, if you wanted to select distinct rows, why didn't you apply select distinct instead of using group by? Result is the same, but - group by is generally used with aggregates, not to return distinct result.
I have two tables on Oracle database, one is named departments_table and the other is locations_table. The departments.table has dep_id, dep_name, location_id, staff_id, employer_id. The locations table consists of location_id, city_id, streetname_id and postcode_id. How do I calculate the number of departments that each location has?
This is the code below is what I have tried to replicate but have been unsuccessful. The error message below that is what shows once the code has submitted.
SELECT dep_name, location_id,
COUNT(*)
FROM departments_table
WHERE location_id => 1
GROUP BY dep_name;
The results of this is an error, " not a single group function "
If you want to count how many departments are in each location, then you must group by location, not by department name, right? Let's start with that.
Then, you don't need ANYTHING about the individual departments in the output of the query, do you? You just need the location id and the count of departments.
select location_id, count(*) as cnt
from departments_table
group by location_id
;
This does most of the work. You may want to add the location name (city, address, etc.), which is/are stored elsewhere - in the locations_table. So you will need a join. And there may be locations in that table that are not, in fact, the location of any department (their id doesn't appear in the departments_table at all). If so, you would need an OUTER join. Also for those departments you probably want to show a count of 0 (rather than null) - you can "fix" that with the nvl() function. So you will end up with something like
select l.*, nvl(g.cnt, 0) as department_count
from locations_table l
left outer join
( select location_id, count(*) as cnt
from departments_table
group by location_id
) g
on l.location_id = g.location_id
;
SELECT l.location_id, l.city, COUNT(d.DEPARTMENT_ID)
FROM OEHR_LOCATIONS l, OEHR_DEPARTMENTS d WHERE l.location_id = d.location_id
GROUP BY l.location_id, l.city ORDER BY l.city;
This method works. I created aliases and made minor changes. OEHR stands for the table names so ignore that.
I'm using a subquery for a join operation. When I hard-code parameters, things work fine. But those parameters must come from outer sql which I believe is referred to as correlated query. I would like to pass them in using table aliases but this results in invalid identifier.
Example invented for the purpose of question:
SELECT
PR.PROVINCE_NAME
,CO.COUNTRY_NAME
FROM
PROVINCE PR
JOIN (
SELECT COUNTRY_ID, COUNTRY_NAME
FROM COUNTRY
WHERE COUNTRY_ID=PR.COUNTRY_ID
) CO ON CO.COUNTRY_ID=PR.COUNTRY_ID
WHERE
PR.PROVINCE_ID IN (1,2)
This is typed in, so I hope I haven't introduced any syntax issues here. The question is specifically about COUNTRY_ID=PR.COUNTRY_ID following the WHERE clause. Are aliases legal in such subqueries?
You are using the alias in two different locations. For one it is legal, for the other it is not:
SELECT pr.province_name, co.country_name
FROM province pr
JOIN (
SELECT country_id, country_name
FROM country
WHERE country_id = pr.country_id --<< this reference to the outer table/alias is invalid
) co ON co.country_id = pr.country_id -- this is valid
WHERE pr.province_id IN (1,2)
With a (standard) join to a derived table, the inner select can't access an alias or table from the outer select. The "invalid identifier" that you get is cause by the line WHERE country_id = pr.country_id.
Given your JOIN condition you can safely remove that without changing the result. And the Oracle optimizer is smart enough to push that condition into the derived table.
In fact the optimizer will rewrite the query to:
SELECT pr.province_name, co.country_name
FROM province pr
JOIN country co ON co.country_id = pr.country_id
WHERE pr.province_id IN (1,2);
There is however a way of accessing table (or aliases) from the outer query in a derived table: it's called a lateral join.
This is part of the SQL standard, but you need Oracle 12 in order to be able to use it:
The following is legal:
SELECT pr.province_name,co.country_name
FROM province pr
JOIN LATERAL (
SELECT country_id, country_name
FROM country
WHERE country_id = pr.country_id
) co ON co.country_id = pr.country_id
WHERE pr.province_id IN (1,2)
I am wondering what determines the order of columns returned in a SQL query.
For example, SELECT * FROM SOMETABLE;
SQ_ID |BUS_TYPE |VOIP |LOCAL_PHONE
--------|-----------|---------|-------------
SQ000001|Business |Y |N
I am guessing the attribute COLUMN_ID determines this. In the case of a table join, for example, SELECT * FROM SOMETABLE LEFT JOIN OTHERTABLE USING (SOME_COL); how is the order now determine.
The order of columns in SELECT * FROM some_table is determined by the column_id of each column, as seen in USER_TAB_COLUMNS.
The order of columns in SELECT * FROM some_table JOIN other_table is all the columns for each table starting with the leftmost table after the FROM clause. In other words, this ...
SELECT * FROM some_table JOIN other_table
... is equivalent to this ...
SELECT some_table.*, other_table.* FROM some_table JOIN other_table
Changing that inner join to LEFT JOIN or RIGHT JOIN won't change the projection.
This is, of course, theoretical. We should never use select * in production code. Explicit column declarations, with table aliases when joining, are always safer. Apart from better expression of intent, explicit projections protect our code from future changes to the tables such as adding a LOB column or a column name which creates ambiguity with a joined table's column.
You can list the order of the colums in the Select statement:
SELECT SOME_COL, SOME_OTHER_COL
FROM SOMETABLE LEFT JOIN OTHERTABLE USING (SOME_COL)
But you also speak of the ID influencing the order and of ordering in general. So I think you could also be looking for ORDER BY to order the rows:
SELECT *
FROM SOMETABLE LEFT JOIN OTHERTABLE USING (SOME_COL)
ORDER BY SOME_COL
What also comes quite handy in this case is the use of aliases. Especally when both tables have coloums with the same name:
SELECT s.some_col, o.some_col
FROM SOMETABLE s LEFT JOIN OTHERTABLE o ON(o.id = s.id)
ORDER BY o.SOME_COL
I use the ON JOIN syntax in this case, because i find this more intuive when using aliases but it should also work with USING.
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];