I'm a beginner at SQL and have this fairly easy conditional problem: Every installation number in the database has a customer. But I have been told that the customer is in either the AUDEB table or the AFORD table. I should first look in AUDEB for CUSTOMER_NO and use that if it is not NULL. If it is NULL, then take the CUSTOMER_NO from the AFORD table.
Use this if CUSTOMER_NO is not NULL
SELECT CUSTOMER_NO
FROM AUDEB
WHERE INST_NO = 2
Else use this CUSTOMER_NO
SELECT CUSTOMER_NO
FROM AFORD
WHERE INST_NO = 2
I see that there exist IF...ELSE condtions in SQL, but isn't there an easier way of selecting between the values from two queries where I want to use the first if the result is not null, else use the other?
You could union the tables using a subquery to retrieve a complete list of customers:
select CUSTOMER_NO
from (
select CUSTOMER_NO
, INST_NO
from AUDEB
union all
select CUSTOMER_NO
, INST_NO
from AFORD
) as all_customers
where INST_NO = 2
If the two tables follow the same schema and there is no overlap in customrer_no you could use UNION:
SELECT T.CUSTOMER_NO
FROM (SELECT CUSTOMER_NO, INST_NO FROM AUDEB
UNION
SELECT CUSTOMER_NO, INST_NO FROM AFORD) AS T
WHERE T.INST_NO = 2
Or if the inst_no could be in both tables then join them (even if the schemas differ)
SELECT COALESCE(T1.Customer_no, T2.CUSTOMER_NO)
FROM AUDEB as T1
FULL OUTER JOIN AFORD as T2
ON T1.INST_NO = T2.INST_NO
WHERE T1.INST_NO = 2 OR T2.INST_NO = 2
COALESCE will return the first non null result
Just join both tables and use ISNULL() to get the value from the corresponding table.
SELECT ISNULL(A.CUSTOMER_NO, B.CUSTOMER_NO) AS CUSTOMER_NO
FROM AUDEB A INNER JOIN AFORD B
ON A.INST_NO = B.INST_NO
WHERE A.INST_NO = 2
Edit: This assumes INST_NO is the primary key, but now it's been stated in comments that it is not. The OP should use the correct fields to join this 2 tables.
Related
I have a table called customer_transactions and a table called blacklist.
The customer_transactions table has a column called atm_name.
Both tables share a unique key called id.
How can I intersect the two tables in such a way that the query shows me
customers that appear on both tables.
a corresponding column that displays the times that they had used a
certain atm alongside the atm's name
(for instance: id_1 -- bank of america -- 2; id_1 -- citibank -- 3;
id_2 -- bank of america -- 1; id_2 -- citibank -- 4, etcetera).
I have something like this
SELECT id,
atm_name,
count(atm_name) as atm_count
FROM customer_transactions
GROUP BY id, atm_name
How can I INTERSECT this table with the blacklist table and maintain what I currently have as output?
Thanks in advance.
You seem to want a join. Assuming that column id relates the two tables, and that it is a unique key in blacklist, you can do:
select ct.id, ct.atm_name, count(*) as atm_count
from customer_transactions ct
inner join blacklist b on b.id = ct.id
group by ct.id, ct.atm_name
You can also express this logic with exists and a correlated subquery:
select ct.id, ct.atm_name, count(*) as atm_count
from customer_transactions ct
where exists (select 1 from blacklist b where b.id = ct.id)
group by ct.id, ct.atm_name
So in one table I can use a replace and charindex to extract a specific ID that relates to a PK in another table, I want to then join the data from the other table based on the trimmed value, how can I do this?
select top 100 *, Replace(Left(LogValue,Charindex(';', LogValue) - 1) ,'RtaId=', '') as TaskID, PrmRoutingTask.*
from SytLog
inner join PrmRoutingTask on RtaId = TaskID
where LogTableName like '%Routing%' and LogValue like '%RtaAniId=397%'
order by 5 desc;
The problem I get is that the temp column name I create (TaskID) is not working in the inner join where in fact the results of TaskID have the reference to the RtaId in the RoutingTask table.
Assuming LogValue belongs to the first table you can use the column named TaskID if you produce a subquery as a table expression of the main query.
For example you can produce the column in the table expression a by doing:
select top 100
a.*,
PrmRoutingTask.*
from (
select *,
Replace(Left(LogValue,Charindex(';', LogValue) - 1) ,'RtaId=', '') as TaskID
from SytLog
) a
inner join PrmRoutingTask on PrmRoutingTask.RtaId = a.TaskID
where LogTableName like '%Routing%'
and LogValue like '%RtaAniId=397%'
order by 5 desc
I'm comparing two tables that share unique values between each other using NOT IN function in Oracle but I'm getting
select count(distinct CHARGING_ID) from BILLINGDB201908 where CDR_TYPE='GPRSO'
the output is: 521254 for all charging ids --< this is the total unique charging ID's in BILLINGDB201908
Now I want to find id's in table BILLINGDB201908 that also exist in table CBS_CHRG_ID_AUG
select count(distinct CHARGING_ID) from BILLINGDB201908 where CDR_TYPE='GPRSO'
AND charging_id IN (select CHARGINGID from CBS_CHRG_ID_AUG);
--- the result back315567 charging ID exist BILLINGDB201908 and also exist in CBS_CHRG_ID_AUG
Now I want to find charging ids that not exist in CBS_CHRG_ID_AUG but exist BILLINGDB201908
select count(distinct CHARGING_ID) from prmdb.CDR_TAPIN_201908#prmdb where CDR_TYPE='GPRSO'
AND charging_id NOT IN (select CHARGINGID from CBS_CHRG_ID_AUG);
--the result back 0 !? I should get 205687 exactly because 521254-315567 = 205687 ?
NOT IN returns no rows if any value from the subquery is NULL. Hence, I strongly, strongly recommend NOT EXISTS:
SELECT count(distinct CHARGING_ID)
FROM prmdb.CDR_TAPIN_201908#prmdb ct
WHERE CDR_TYPE = 'GPRSO' AND
NOT EXISTS (SELECT 1
FROM CBS_CHRG_ID_AUG ccia
WHERE ccia.charging_id = ct.charging_id
);
I also recommend changing your first query to EXISTS. In fact, just don't use IN and NOT IN with subqueries, and you won't have this problem.
The missing record is having null value CHARGINGID.
Please try doing select where CHARGINGID is null vs is not null
I would recommend not exists rather than not in; it is null-safe, and usually more efficient:
select count(distinct charging_id)
from billingdb201908 b
where
b.cdr_type = 'gprso'
and not exists (select 1 from cbs_chrg_id_aug a where a.chargingid = b.chargingid)
You can get this list using LEFT OUTER JOIN.
SQL to return list of charging ids that not exist in CBS_CHRG_ID_AUG but exist BILLINGDB201908 -
select count(distinct CHARGING_ID)
from prmdb.CDR_TAPIN_201908#prmdb a
left join CBS_CHRG_ID_AUG b on a.CHARGING_ID = b.CHARGINGID
where a.CDR_TYPE='GPRSO' and b.CHARGINGID is null;
There are two dangers with not in when the subquery key may contain nulls:
If there actually is a null value, you may not get the result you were expecting (as you have found). The database is actually correct, even though nobody in the history of SQL has ever expected this result.
Even if all key values are populated, if it is possible for the key column to be null (if it is not defined as not null) then the database has to check in case there is a null value, so queries are limited to inefficient row by row filter operations, which can perform disastrously for large volumes. (This was true historically, although these days there is a Null-aware anti-join and so the performance issue may not be so disastrous.)
create table demo (id) as select 1 from dual;
select * from demo;
ID
----------
1
create table table_with_nulls (id) as (
select 2 from dual union all
select null from dual
);
select * from table_with_nulls;
ID
----------
2
select d.id
from demo d
where d.id not in
( select id from table_with_nulls );
no rows selected
select d.id
from demo d
where d.id not in
( select id from table_with_nulls
where id is not null );
ID
----------
1
The reason is that 1 <> null is null, not false. If you substitute a fixed list for the not in subquery, it would be:
select d.id
from demo d
where d.id not in (2, null);
which is really the same thing as
select d.id
from demo d
where d.id <> 2 and d.id <> null;
Obviously d.id <> null will never be true. This is why your not in query returned no rows.
this is more like a general question.
I am looking for the best way to join 4, maybe 5 different tables. I am trying to create a Power Bi pulling live information from an IBM AS400 where customer service can type one of our parts number,
see how many parts we have in inventory, if none, see the lead time and if there are any orders already already entered for the typed part number.
SERI is our inventory table with 37180 records.
(active inventory that is available)
METHDM is our kit table with 37459 records.
(this table contains the bill of materials for custom kits, KIT A123 contains different part numbers in it witch are in SERI as well.)
STKA is our part lead time table with 76796 records.
(lead time means how long will it take for parts to come in)
OCRI is our sales order table with 6497 records.
(This table contains all customer orders)
I have some knowledge in writing queries but this one is more challenging of what I have created in the past. Should I start with the table that has the most records and start left joining the rest ?
From STKA 76796 records
Left join METHDM 37459 records on STKA
left join SERI 37180 records on STKA
left join OCRI 6497 records on STAK
Select
STKA.v6part as part,
STKA.v6plnt as plant,
STKA.v6tdys as pur_leadtime,
STKA.v6prpt as Pur_PrepLeadtime,
STKA.v6lead as Mfg_leadtime,
STKA.v6prpt as Mfg_PrepLeadTime,
METHDM.AQMTLP AS COMPONENT,
METHDM.AQQPPC AS QTYNEEDED,
SERI.HTLOTN AS BATCH,
SERI.HTUNIT AS UOM,
(HTQTY - HTQTYC) as ONHAND,
OCRI.DDORD# AS SALESORDER,
OCRI.DDRDAT AS PROMISED
from stka
left join METHDM on STKA.V6PART = METHDM.AQPART
left join SERI on STKA.V6PART = SERI.HTPART
left join OCRI on STKA.V6PART = OCRI.DDPART
Is this the best way to join the tables?
I think you already have your answer, but conceptually, there are a few issues here to deal with, and I figured I would give you a few examples, using data a little bit like yours, but massively simplified.
CREATE TABLE #STKA (V6PART INT, OTHER_DATA VARCHAR(50));
CREATE TABLE #METHDM (AQPART INT, KIT_ID INT, SOME_DATE DATETIME, OTHER_DATA VARCHAR(50));
CREATE TABLE #SERI (HTPART INT, OTHER_DATA VARCHAR(50));
CREATE TABLE #OCRI (DDPART INT, OTHER_DATA VARCHAR(50));
INSERT INTO #STKA SELECT 1, NULL UNION ALL SELECT 2, NULL UNION ALL SELECT 3, NULL; --1, 2, 3 Ids
INSERT INTO #METHDM SELECT 1, 1, '20200108 10:00', NULL UNION ALL SELECT 1, 2, '20200108 11:00', NULL UNION ALL SELECT 2, 1, '20200108 13:00', NULL; --1 Id appears twice, 2 Id once, no 3 Id
INSERT INTO #SERI SELECT 1, NULL UNION ALL SELECT 3, NULL; --1 and 3 Ids
INSERT INTO #OCRI SELECT 1, NULL UNION ALL SELECT 4, NULL; --1 and 4 Ids
So fundamentally we have a few issues here:
o the first problem is that the IDs in the tables differ, one table has an ID #4 but this isn't in any of the others;
o the second issue is that we have multiple rows for the same ID in one table;
o the third issue is that some tables are "missing" IDs that are in other tables, which you already covered by using LEFT JOINs, so I will ignore this.
--This will select ID 1 twice, 2 once, 3 once, and miss 4 completely
SELECT
*
FROM
#STKA
LEFT JOIN #METHDM ON #METHDM.AQPART = #STKA.V6PART
LEFT JOIN #SERI ON #SERI.HTPART = #STKA.V6PART
LEFT JOIN #OCRI ON #OCRI.DDPART = #STKA.V6PART;
So the problem here is that we don't have every ID in our "anchor" table STKA, and in fact there's no single table that has every ID in it. Now your data might be fine here, but if it isn't then you can simply add a step to find every ID, and use this as the anchor.
--This will select each ID, but still doubles up on ID 1
WITH Ids AS (
SELECT V6PART AS ID FROM #STKA
UNION
SELECT AQPART AS ID FROM #METHDM
UNION
SELECT HTPART AS ID FROM #SERI
UNION
SELECT DDPART AS ID FROM #OCRI)
SELECT
*
FROM
Ids I
LEFT JOIN #STKA ON #STKA.V6PART = I.Id
LEFT JOIN #METHDM ON #METHDM.AQPART = I.Id
LEFT JOIN #SERI ON #SERI.HTPART = I.Id
LEFT JOIN #OCRI ON #OCRI.DDPART = I.Id;
That's using a common-table expression, but a subquery would also do the job. However, this still leaves us with an issue where ID 1 appears twice in the list, because it has multiple rows in one of the sub-tables.
One way to fix this is to pick the row with the latest date, or any other ORDER you can apply to the data:
--Pick the best row for the table where it has multiple rows, now we get one row per ID
WITH Ids AS (
SELECT V6PART AS ID FROM #STKA
UNION
SELECT AQPART AS ID FROM #METHDM
UNION
SELECT HTPART AS ID FROM #SERI
UNION
SELECT DDPART AS ID FROM #OCRI),
BestMETHDM AS (
SELECT
*,
ROW_NUMBER() OVER (PARTITION BY AQPART ORDER BY SOME_DATE DESC) AS ORDER_ID
FROM
#METHDM)
SELECT
*
FROM
Ids I
LEFT JOIN #STKA ON #STKA.V6PART = I.Id
LEFT JOIN BestMETHDM ON BestMETHDM.AQPART = I.Id AND BestMETHDM.ORDER_ID = 1
LEFT JOIN #SERI ON #SERI.HTPART = I.Id
LEFT JOIN #OCRI ON #OCRI.DDPART = I.Id;
Of course you could also add some aggregation (SUM, MAX, MIN, AVG, etc.) to fix this problem (if it is indeed an issue). Also, I used a common-table expression, but this would work just as well with a subquery.
Expanding on a comment made on the question..
I would say I will start with SERI as that table contains the entire inventory for our facility and should cover the other tables
However the question said
SERI is our inventory table with 37180 records. (active inventory that is available)
In my experience, active inventory, isn't the same as all parts.
Normally, in a query like this, I'd expect the first table to be a Parts Master table of some sort that contains every possible part ID.
I have a large list of CustIDs that I need to query on to find if they are within the CUSTOMER table; I want the result to tell me which CustIDs ARE on the table and which CustIDs are NOT on the table.
I provided a short list below to give an idea of what I need to do.
Oracle database
Table: Customer
Primary Key: CustID
Scenario:
Customer table only has the following (2) CustID: ‘12345’, ‘56789’
Sql:
Select * from CUSTOMERS where CUSTID in (‘12345’, ‘56789’, ‘01234’);
I want the result to tell me that both ‘12345’ and ‘56789’ are in the table, AND that ‘01234’ is NOT.
select
v.CustID,
exists (select * from Customer where Customer.CustID = v.CustID)
from (values (12345), (56789), (01234)) v (CustID);
Results:
custid exists
12345 true
56789 true
1234 false
You need a left join or subquery for this. The precise syntax varies by database. Typical syntax is:
select i.custid,
(case when c.custid is not null then 1 else 0 end) as exists_flag
from (select '12345' as custid union all
select '56789' union all
select '01234'
) ci left join
customers c
on c.cust = i.custid;