full join & where condition - sql

select *
from Table1
full join Table2 on Table2.Common = Table1.Common
In the above query, I want to add this where condition:
where (Table1.StatusId > 100 or Table1.StatusId is not null)
StatusId is of datatype numeric(18, 2).
The problem is when I use the where condition, rows in Table2 which don't have any connecting data in Table1 are not showing up anymore.
Is there any other way to add this where condition?

Try put it on a Subquery.
SELECT *
FROM ( SELECT *
FROM Table1
WHERE ( Table1.StatusId > 100
OR Table1.StatusId IS NOT NULL
)
) T
FULL JOIN Table2 ON Table2.Common = t.Common

Move the t1.StatusId is NOT NULL filter to ON condition
SELECT *
FROM Table1 t1
FULL JOIN Table2 t2
ON t1.Common = t1.Common
AND t1.StatusId is NOT NULL
The problem in your query is, in table1 status column for the non matching records NULL values will be present which will be filtered by applying the Where condition Where t1.StatusId is NOT NULL. So move it to ON clause which tells what are the records to joined instead of filtering the result

You can just add a AND (Table1.StatusId > 100 or Table1.StatusId is not null) after your ON-Statement

If you want to apply the where condition to the result of the join condition then
select *
from Table1
full join Table2 on Table2.Common = Table1.Common where Table1.StatusId > 100 or Table1.StatusId is not null
This result will probably not have the data from Table2 which has no connected data from Table1 because of your condition(Table1.StatusId is not null).
If you want the join to condition to be executed for only filtered records of Table1 then
select * from Table2 full join (select * from Table1 where StatusId > 100 or StatusId is not null ) T on Table2.Common = T.Common

select *
from Table2
Full join Table1 on Table2.Common = Table1.Common
where (Table2.StatusId > 100 or Table2.StatusId is not null)

Related

SQL statement to check if data exists in one table and not in two other tables

I'm creating 1 temp table (temp1) using table1.
and I want to check if data from temp table is present in table1 and table2.
table1 and table2 have same columns.
It's difficult to assess exactly what you need without further detail, but you could try a LEFT JOIN and a COUNT here to indicate whether there are any matching rows (whereby anything over 0 indicates matching rows)
SELECT
COUNT(*) AS matching_rows
FROM
(
SELECT
1 AS 'ColumnA'
) AS T1
LEFT OUTER JOIN
(
SELECT
2 AS 'ColumnA'
) AS T2
ON T1.ColumnA = T2.ColumnA
WHERE
T2.ColumnA IS NOT NULL
You can also use an INNER JOIN for this:
SELECT
COUNT(*) AS matching_rows
FROM
(
SELECT
1 AS 'ColumnA'
) AS T1
INNER JOIN
(
SELECT
2 AS 'ColumnA'
) AS T2
ON T1.ColumnA = T2.ColumnA

Update row in a table based on multiple rows in another table

I have two tables: table1 and table2:
table1 has columns id and integer
table2 has columns id and boolean
table2 can have multiple rows with the same id
I want to update the integer column of table1 by looking at all rows with the same id in table2 and seeing if any of the boolean values are true. If so I want table1.integer to be 1, else I want it to be 0.
I have tried something like this:
UPDATE table1,
(
SELECT table2.id, Sum(table2.boolean) > 0
) AS 'condition'
from table2
WHERE 1
GROUP BY table2.id) table3
SET table1.integer =IF(table3.condition, 1, 0) where table1.id = table3.id
And it seems to work, but I wanted to ask if there is a nicer/cleaner/more succinct way of updating the rows of table1 according to multiple rows of table2.
I would recommend EXISTS:
UPDATE table1 t1
SET t1.integer = (EXISTS (SELECT 1
FROM table2 t2
WHERE t2.id = t.id AND
t2.boolean
)
);
This can take advantage of an index on table2(id, boolean). With such an index, it should be faster than an approach that uses JOIN and AGGREGATION.
The syntax of your query is MySql like, so you can do a join like this:
UPDATE table1 t1 INNER JOIN (
SELECT id, MAX(boolean) maxboolean
FROM table2
GROUP BY id
) t2 ON t2.id = t1.id
SET t1.integer = t2.maxboolean
If there are ids in table1 without a corresponding id in table2 and you want the integer column for them to be updated to 0 then use a LEFT join:
UPDATE table1 t1 LEFT JOIN (
SELECT id, MAX(boolean) maxboolean
FROM table2
GROUP BY id
) t2 ON t2.id = t1.id
SET t1.integer = COALESCE(t2.maxboolean, 0)

How to get first row value from third table while joining three tables

I'm new to mssql .Here am trying to get values from database by joining three tables .
Table 1:
Table 2 :
Here the image there is a possibility for a single user can have multiple image id form this I need to take any one of the image.
Table 3 :
Here am joining the Table 1 and Table 2 by using H_ID
and Table 2 and Table 3 by using IMG_ID.
What I want to do is Need to get all the colum values from Table 1 and Table 2 But the first URL from the Table 3.
In this case an employee has multiple images in the Table I need to take the 1 URL.
Result should be like this :
Query :
SELECT T1.H_ID AS 'ID',
T1.NAME,
T1.ROLE,
T2.SALARY,
T3.IMAGE
FROM TABLE1 T1
JOIN TABLE2 T2
ON T1.H_ID T2.H_ID
JOIN TABLE3 T3
ON T3.IMG_ID = T2.IMG_ID
WHERE T1.STATUS = 'ACTIVE'
Now this query returns 3 rows for the id H_ID = 1001 but It should be a single row.
Can anyone help me to fix this .
use row_number()
with cte as
(SELECT T1.H_ID AS 'ID',T1.NAME,T1.ROLE,T2.SALARY,T3.IMAGE
,row_number() over(partition by T2.img_id order by T3.id) rn
FROM TABLE1 T1
JOIN TABLE2 T2
ON T1.H_ID T2.H_ID
JOIN TABLE3 T3
ON T3.IMG_ID = T2.IMG_ID WHERE T1.STATUS = 'ACTIVE'
) select * from cte where rn=1
After you comments it seems you need subquery
select T1.*,T2.sal,a.url
FROM TABLE1 T1
JOIN TABLE2 T2
ON T1.H_ID T2.H_ID
left join ( select min(id),img_id,url from table3 group by img_id,url) a
on T2.IMG_ID= a.img_id
WHERE T1.STATUS = 'ACTIVE'
I think, You can simply use OUTER APPLY and TOP 1 for that
SELECT T1.H_ID AS 'ID',
T1.NAME,
T1.ROLE,
T2.SALARY,
T3.IMAGE
FROM TABLE1 T1
JOIN TABLE2 T2 ON T1.H_ID T2.H_ID
OUTER APPLY(SELECT TOP 1 T3.IMAGE
FROM TABLE3 T3 WHERE T3.IMG_ID = T2.IMG_ID
--ORDER BY <column_name> --to take top 1 value in specific order
) T3
WHERE T1.STATUS = 'ACTIVE'

SQL LEFT JOIN with WHERE class

there are two tables TABLE1 and TABLE2 in TABLE1 there are records which does not exist in TABLE2 with left join below i wanted to query all records which are in TABLE1 if the record does not exist in table2 however.
Note: about WHERE class in my code that is required this is because, there can be several records in the name of 'IN PROGRESS' in TABLE2 with one record in the name of 'GRADUATED' i wanted to distinct records based on table 1 ID that if there is any record in the name of 'GRADUATE' it should show only that else it should show inprogress.
SELECT DISTINCT
TABLE1.ID,
TABLE2.TRAINING_STATUS_CHECK
FROM TABLE1
LEFT JOIN TABLE2
ON TABLE1.ID = TABLE2.FK_ID_CLASS
WHERE NOT EXISTS
(
SELECT DISTINCT
TABLE1.ID,
TABLE2.TRAINING_STATUS_CHECK
FROM TABLE1
LEFT JOIN TABLE2
ON TABLE1.ID = TABLE2.FK_ID_CLASS
WHERE TABLE2.TRAINING_STATUS_CHECK = 'GRADUATED')
OR TABLE2.TRAINING_STATUS_CHECK = 'GRADUATED'
I see some odds with your query:
exists part are not related with you main query. I think you need some relation
distinct in part not exists are not needed
You filter columns with the same conditions as filter main row set
As I understand you want to get all rows from table1 with state 'GRADUATED' int table2 and any row from table1 where rows in table2 are not exists or state not equal 'GRADUATED'
SELECT DISTINCT
t1.ID,
t2.TRAINING_STATUS_CHECK
FROM TABLE1 t1
LEFT JOIN TABLE2 t2 ON t1.ID = t2.FK_ID_CLASS
WHERE NOT EXISTS
(
SELECT NULL /*its not nesessary what you need*/
FROM TABLE1 sub_t1
JOIN TABLE2 sub_t2 ON sub_t1.ID = sub_t2.FK_ID_CLASS /* left join replaced to inner */
WHERE sub_t2.TRAINING_STATUS_CHECK = 'GRADUATED'
AND sub_t1.ID = t1.ID /*relation with outer query*/
)
OR t2.TRAINING_STATUS_CHECK = 'GRADUATED'
where the relatonship between tables does not exist - but only if the comparison involves rows in table that are not 'graduated' (I think)
SELECT DISTINCT
TABLE1.ID,
TABLE2.TRAINING_STATUS_CHECK
FROM TABLE1
LEFT JOIN TABLE2 ON TABLE1.ID = TABLE2.FK_ID_CLASS
AND TABLE2.TRAINING_STATUS_CHECK <> 'GRADUATED'
WHERE TABLE2.FK_ID_CLASS IS NULL
Not sure about your question but if you want all the records from table 1 who are not in table 2, you just have to do this :
SELECT TABLE1.ID
FROM TABLE1
LEFT JOIN TABLE2 ON TABLE1.ID = TABLE2.FK_ID_CLASS
WHERE TABLE2.FK_ID_CLASS IS NULL
Try this:
SELECT DISTINCT TABLE1.ID, TABLE2.TRAINING_STATUS_CHECK
FROM TABLE1
LEFT JOIN TABLE2
ON TABLE1.ID = TABLE2.FK_ID_CLASS
AND (NOT EXISTS (SELECT 1
FROM TABLE2 t
WHERE TABLE1.ID = t.FK_ID_CLASS
AND t.TRAINING_STATUS_CHECK = 'GRADUATED')
OR TABLE2.TRAINING_STATUS_CHECK = 'GRADUATED')
For the record, conditions on the right table of a LEFT JOIN need to be placed inside the ON() clause or the join will transfer into an INNER JOIN due to NULL comparison.
It seems to me you have three distinct cases that can be "ORed together" using UNION; personally I find keeping all three separated like this makes things much easier to read and understand:
--- ID with GRADUATED exists in TABLE2
( SELECT ID, 'GRADUATED' AS TRAINING_STATUS_CHECK
FROM TABLE1
INTERSECT
SELECT FK_ID_CLASS, 'GRADUATED'
FROM TABLE2
WHERE TRAINING_STATUS_CHECK = 'GRADUATED' )
UNION
--- ID without GRADUATED exists in TABLE2
( SELECT ID, 'IN PROGRESS'
FROM TABLE1
MINUS
SELECT FK_ID_CLASS, 'IN PROGRESS'
FROM TABLE2
WHERE TRAINING_STATUS_CHECK = 'GRADUATED' )
UNION
--- ID does not exist in TABLE2
( SELECT ID, '{{NONE}}'
FROM TABLE1
WHERE ID NOT IN ( SELECT FK_ID_CLASS FROM TABLE2 ) );

Multiple SELECT with NOT IN - inner Select statement returns empty and the whole SELECT returns empty

There are two table TABLE1 and TABLE2 in which there is a common field ID. I wanted to retrieve values from TABLE2 that doesnot match in TABLE1 based on ID value.
select * from TABLE2 where subject = 1 and ID NOT IN (select ID from TABLE1 where subject = 1)
Sample:
TABLE1 ID SUBJECT 1 1
TABLE2 ID SUBJECT 1 1 2 1
The expected result is 2 and it works fine.
But when TABLE1 is empty or the inner select ID from TABLE1 where subject = 1 returns empty, the whole select statement returns empty.
But the expected result is 1, 2
Is there any way to achieve this ?
Use a left join
select t2.*
from table2 t2
left outer join table1 t1 on t1.id = t2.id and t1.subject = 1
where t2.subject = 1
and t1.id is null
See a good explanation of joins
I think you can use not exists also for this work -
select * from TABLE2 where subject = 1 and NOT exists
(select 1 from TABLE1 where subject = 1 and table1.id = table2.id)