Hi I am new to the Database, and i am trying to get the records from the multiple tables, but depending upon there selection following is my tables
Table1
Column1 Column2
1 10
2 25
3 23
4 15
5 7
Table2
Column1 Column2
2 15
3 13
5 17
Table3
Column1 Column2
2 45
Resultant Table should have records like
Column1 Column2
1 10
2 45
3 13
4 15
5 17
i am trying but not got the output yet. Any help or the direction to work out this output will be great help.
UPDATE
What i want is get the all rows from table1 then if table2 contains the matching records then it will remove the matching records form the resultset and add the table2 matching records and then same is repeated by table3.
SELECT t1.column1, COALESCE(t3.column2,t2.column2,t1.column2)
FROM t1
LEFT JOIN t2 on t1.column1=t2.column1
LEFT JOIN t3 on t1.column1=t3.column1
Please use the Below Code and Try
select * from table1 where column1 not in ( select column1 from table2 union select column1 from table3)
union
select * from table2 where column1 not in (select column1 from table3)
union
select * from table3
select x.col1,max(x.col2) from (
select * from #t1
union
select * from #t2
union
select * from #t3
)x
group by x.col1
see it in action
Related
I want to split a table into two tables (or more, but let's say two).
table_original
id column1 column2
1 1 2
2 1 3
3 1 4
4 1 4
5 1 5
We can also assume that id is a unique identifier. Now I split this table into two, by using a CREATE TABLE table1 AS SELECT * FROM table_original WHERE column2 <= 4 and CREATE TABLE table2 AS SELECT * FROM table_original WHERE column2 >= 4. Now I have these two tables:
table1
id column1 column2
1 1 2
2 1 3
3 1 4
4 1 4
table2
id column1 column2
3 1 4
4 1 4
5 1 5
How to get the same results from those two tables that I can get from the original table? If I run a query SELECT * FROM table1 UNION SELECT * FROM table2 it will be the same as SELECT * FROM table_original because of the unique id value, however if I run a query SELECT column1, column2 FROM table1 UNION SELECT column1, column2 FROM table2 it returns:
column1, column2
1 2
1 3
1 4
1 5
which is not the same as SELECT column1, column2 FROM table_original, which returns:
column1, column2
1 2
1 3
1 4
1 4
1 5
Duplicates from the same table are removed. However, if I wanted to let's say do a count on duplicates, the results will be different, which is bad. So is there a way to do a UNION type operation but keep duplicates that are found in the same table?
not sure what are you trying to achieve but you need to use union all:
SELECT column1, column2 FROM table1
UNION ALL
SELECT column1, column2 FROM table2
union all keeps the duplicates
The UNION on whole rows in your solution will be painfully expensive for big tables (and wide rows). And it fails outright with any column type that doesn't support the equality operator (like json). See:
UNION ALL on JSON data type
This query is substantially faster, making use of the unique index on table1(id). (Create that index if you don't have it!)
SELECT column1, column2
FROM table1 -- bigger table first to micro-optimize some more
UNION ALL
SELECT column1, column2
FROM table2 t2
WHERE NOT EXISTS (SELECT FROM table1 WHERE id = t2.id)
See:
Select rows which are not present in other table
About UNION ALL (as opposed to just UNION):
Is order preserved after UNION in PostgreSQL?
Combining 3 SELECT statements to output 1 table
The question remains: Why keeps completely duplicate rows in multiple tables?
I've figured out the answer.
To keep the duplicates found in the same table, but eliminate everything else, I used a query SELECT column1, column2 FROM (SELECT * FROM table1 UNION SELECT * FROM table2) AS t;
This way the UNION uses the unique id values to eliminate real duplicates, and after that I just filter the result to get the columns I need.
I want to search between 2 tables but that field i want to search is foreign key in other table
my tables are like this:
table 1
ID TitleSR
1 888
2 999
table 2
ID TitleSR
1 11
2 22
3 33
4 44
table contain value
ID value
11 italy
22 swiss
888 lilium
999 mount
33 england
I think I understand you. Try this one:
Select *
From table3 as VCT Inner Join
(Select * From table1
Union
Select * From table2) as FGT
On VCT.ID = FGT.TitleSR
Where value = 'italy';
You can use either of these methods:
Returns only t1 fields
SELECT * FROM Table1 t1
WHERE t1.ID in (SELECT ID FROM Table2);
Returns ALL fields
SELECT * FROM Table1 t1
JOIN Table2 t2 on t1.ID = t2.ID;
If your 'values' exist in a separate table (tblValues), you can use any of these:
Returns tblValues fields
SELECT * FROM tblValues tval
WHERE tval.ID in (SELECT TitleSR FROM Table1);
returns ALL fields
SELECT *
FROM (tblValues tval
JOIN Table1 t1 on tval.ID = t1.TitleSR)
JOIN Table2 on tval.ID = Table2.TitleSR;
In my two columns of data I would like to keep only the unique values of ColumnOne that have the highest value in ColumnTwo.
For example
ColumnOne ColumnTwo
2 6
3 2
7 8
2 7
3 4
7 3
I would like the results:
ColumnOne ColumnTwo
2 7
3 4
7 8
You can do this with a group by statement:
select Column1, max(Column2)
from your_table
group by Column1
delete t1
from myTable t1
left join (select t2.Column1, max(t2.Column2) maxColumn2
from myTable t2
group by t2.Column1) tMax
on t1.Column1 = tMax.Column1
and t1.Column2 = tMax.maxColumn2
where tMax.Column1 is null
The below query will help you to accomplish your output for tables with huge no. of records:
create table table1_new as (select * from table1) with no data;
insert into table1_new
select columnone, max(columntwo) over(partition by columnone) from table1 group by columnone;
Validate data and then interchange table names:
drop table table1;
rename table1_new to table1;
I was working on preparing a query where I was stuck.
Consider tables below:
table1
id key col1
-- --- -----
1 1 abc
2 2 d
3 3 s
4 4 xyz
table2
id col1 foreignkey
-- ---- ----------
1 12 1
2 13 1
3 14 1
4 12 2
5 13 2
Now what I need is to select only those records from table1 for which the corresponding entries in table2 does not have say col1 value as 12.
So the challenge is after applying join even though it will skip for value 1 corresponding to col1 equal to 12 it still has another multiple rows whose values are say 13, 14 for which also they have same foreignkey. Now what I want is if there is a single row having value 12 then it should not pick that id at all from table1.
How can I form a query with this?
The output which i need is say from above table structure i want to get those records from table1 for which col1 value from table2 does not have value as 14.
so my query should return me only row 2 from table1 and not row 1.
Another way of doing that. The first two queries are just for making the sample data.
;WITH t1(id ,[key] ,col1) AS
(
SELECT 1 , 1 , 'abc' UNION ALL
SELECT 2 , 2 , 'd' UNION ALL
SELECT 3 , 3 , 's' UNION ALL
SELECT 4 , 4 , 'xyz'
)
,t2(id ,col1, foreignkey) AS
(
SELECT 1 , 12 , 1 UNION ALL
SELECT 2 , 13 , 1 UNION ALL
SELECT 3 , 14 , 1 UNION ALL
SELECT 4 ,12 , 2 UNION ALL
SELECT 5 ,13 , 2
)
SELECT id, [key], col1
FROM t1
WHERE id NOT IN (SELECT t2.Id
FROM t2
INNER JOIN t1 ON t1.Id = t2.foreignkey
WHERE t2.col1 = 14)
This is a typical case for NOT EXISTS:
SELECT id, [key], col1
FROM table1 t1
WHERE NOT EXISTS (SELECT 1
FROM table2 t2
WHERE t2.foreignkey = t1.id AND t2.col1 = 14)
The above query will not select a row from table1 if there is a single correlated row in table2 having col1 = 14.
Output:
id key col1
-------------
2 2 d
3 3 s
4 4 xyz
If you want to return records that, in addition to the criterion set above, also have correlated records in table2, then you can use the following query:
SELECT t1.id, MAX(t1.[key]) AS [key], MAX(t1.col1) AS col1
FROM table1 t1
INNER JOIN table2 t2 ON t1.id = t2.foreignkey
GROUP BY t1.id
HAVING COUNT(CASE WHEN t2.col1 = 14 THEN 1 END) = 0
Output:
id key col1
-------------
2 2 d
You can also achieve the same result with the second query using a combination of EXISTS and NOT EXISTS:
SELECT id, [key], col1
FROM table1 t1
WHERE EXISTS (SELECT 1
FROM table2 t2
WHERE t2.foreignkey = t1.id)
AND
NOT EXISTS (SELECT 1
FROM table2 t3
WHERE t3.foreignkey = t1.id AND t3.col1 = 14)
select t1.id,t1.key,
(select ROW_NUMBER() OVER(PARTITION BY col1 ORDER BY col1 DESC) AS Row,* into
#Temp from table1)
from table1 t1
inner join table2 t2 on t1.id=t2.foreignkey
where t2.col1=(select col1 from #temp where row>1)
Using oracle developer, I've run a query that results in the following table. But I only want the results where column1 matches all the values columns 2 (3,4,8). So the output would be 2, 3, but not 4. I'm sure there is a way to bring this result about without hard coding it? I'm thinking its some sort of self-join?
select column1, column2
from table1
where column1 in (
select column1
from table2
where depth >= 100)
order by column2;
Output:
column1 column2
3 2
8 2
4 2
3 3
4 3
8 3
4 4
Table2
Column1 Area_Name Depth
1 Lake 40
2 River 50
3 Ocean 150
4 Cliff 150
5 Mountain 90
6 Construction 60
7 Building 50
8 Random 100
9 Also Random 50
10 Another one 80
Needed output:
column2
2
3
Ok, this is what I was looking for:
SELECT table1.column1
FROM table1
INNER JOIN table2
ON table1.column2 = table2.column2
WHERE table2.depth >= 100
GROUP BY boat_id
HAVING COUNT(*) >= (
select count(*)
from table2
where depth >= 100);
UPDATED
WITH qry AS (
SELECT column1, column2
FROM table1
WHERE column1 IN (
SELECT column1
FROM table2
WHERE depth >= 100)
)
SELECT t1.column2
FROM qry t1 LEFT JOIN qry t2
ON t1.column1 = t2.column1 AND t1.column2 = t2.column2
GROUP BY t1.column2
HAVING COUNT(*) = (SELECT COUNT(DISTINCT column1) FROM qry)
ORDER BY t1.column2
Output:
| COLUMN2 |
-----------
| 2 |
| 3 |
SQLFiddle