I have a database by the name CARS with 2 tables. I need help in querying data from both these tables and get a output based on ID(100)..
Any help is highly appreciated.
he following should answer your question. Ask for the fields you want(with a table identifier) in the SELECT clause and then JOIN the tables on the common ID:
SELECT table1.ID, table1.GroupID, table1.Text, table2.GroupID, table2.Text
FROM table1
JOIN table2
ON table1.ID = table2.ID
or:
Looking at is again I noticed table 1 and table 2 are identical in design, just hte entries are different. You can use UNION ALL to concatenate two SELECT statements
SELECT * FROM table1 UNION ALL SELECT * FROM table2;
:)
To only return the entries with ID = 100
SELECT * FROM table1
WHERE ID = 100
UNION ALL
SELECT * FROM table2
WHERE ID = 100;
Related
I have two tables in Access, one containing IDs (not unique) and some Name and one containing IDs (not unique) and Location. I would like to return a third table that contains only the IDs of the elements that appear more than 1 time in either Names or Location.
Table 1
ID Name
1 Max
1 Bob
2 Jack
Table 2
ID Location
1 A
2 B
Basically in this setup it should return only ID 1 because 1 appears twice in Table 1 :
ID
1
I have tried to do a JOIN on the tables and then apply a COUNT but nothing came out.
Thanks in advance!
Here is one method that I think will work in MS Access:
(select id
from table1
group by id
having count(*) > 1
) union -- note: NOT union all
(select id
from table2
group by id
having count(*) > 1
);
MS Access does not allow union/union all in the from clause. Nor does it support full outer join. Note that the union will remove duplicates.
Simple Group By and Having clause should help you
select ID
From Table1
Group by ID
having count(1)>1
union
select ID
From Table2
Group by ID
having count(1)>1
Based on your description, you do not need to join tables to find duplicate records, if your table is what you gave above, simply use:
With A
as
(
select ID,count(*) as Times From table group by ID
)
select * From A where A.Times>1
Not sure I understand what query you already tried, but this should work:
select table1.ID
from table1 inner join table2 on table1.id = table2.id
group by table1.ID
having count(*) > 1
Or if you have ID's in one table but not the other
select table1.ID
from table1 full outer join table2 on table1.id = table2.id
group by table1.ID
having count(*) > 1
I am attempting a very basic difference function in postgresql. Table 1 and Table 2 have identical columns. Only difference is Table 1 has some surplus rows. I would like to select for surplus rows only:
SELECT *
FROM table1
WHERE NOT EXISTS (SELECT * from table2);
The query above returns nothing when I know there are surplus rows.
I think you are looking for except:
select t1.*
from table1 t1
except
select t2.*
from table2 t2;
Note that the two tables must have the same number of columns, and the columns must all be of the same type. You can review the documentation here.
If you wish to use NOT EXISTS you're missing the joining of your table's keys in the inner where clause. Try:
SELECT *
FROM table1 t1
WHERE NOT EXISTS (SELECT * from table2 t2 WHERE t2.id = t1.id);
Table1: Columns A, B, C
Table2: Columns A, B, C
Table 2 is a copy of Table 1 with different data. Assume all columns to be varchar
Looking for a single efficient query which can fetch:
Columns A, B, C from Table1
Additional Rows from Table2 where values of Table2.A are not present in Table1.A
Any differences between the Oracle SQL & HQL for the same query will be appreciated.
I'm fiddling with Joins, Unions & Minus but not able to get the correct combination.
SQL:
SELECT *
FROM Table1
UNION ALL
SELECT *
FROM Table2 T2
WHERE NOT EXISTS(
SELECT 'X' FROM Table1 T1
WHERE T1.A = T2.A
)
HQL:
You must execute two different query an discard the element by Table2 result in a Java loop because in HQL doesn't exist UNION command.
Alternatatively you can write the first query for Table1 and the second query must have a not in clause to discard Table1 A field.
Solution 1:
Query 1:
SELECT * FROM Table1
Query 2:
SELECT * FROM Table2
and then you apply a discard loop in Java code
Solution 2:
Query 1:
SELECT * FROM Table1
Query 2:
SELECT * FROM Table2 WHERE Table2.A not in (SELECT Table1.A from Table1)
This query returns all rows in table1, plus all rows in table2 which does not exist in table1, given that column a is the common key.
select a,b,c
from table1
union
all
select a,b,c
from table2
where a not in(select a from table1);
There may be different options available depending on the relative sizes of table1 and table2 and the expected overlap.
If I run the two statements in batch will they return one table to two to my sqlcommand object with the data merged. What I am trying to do is optimize a search by searching twice, the first time on one set of data and then a second on another. They have the same fields and I’d like to have all the records from both tables show and be added to each other. I need this so that I can sort the data between both sets of data but short of writing a stored procedure I can’t think of a way of doing this.
Eg. Table 1 has columns A and B, Table 2 has these same columns but different data source. I then wan to merge them so that if a only exists in one column it is added to the result set and if both exist it eh tables the column B will be summed between the two.
Please note that this is not the same as a full outer join operation as that does not merge the data.
[EDIT]
Here's what the code looks like:
Select * From
(Select ID,COUNT(*) AS Count From [Table1]) as T1
full outer join
(Select ID,COUNT(*) AS Count From [Table2]) as T2
on t1.ID = T2.ID
Perhaps you're looking for UNION?
IE:
SELECT A, B FROM Table1
UNION
SELECT A, B FROM Table2
Possibly:
select table1.a, table1.b
from table1
where table1.a not in (select a from table2)
union all
select table1.a, table1.b+table2.b as b
from table1
inner join table2 on table1.a = table2.a
edit: perhaps you would benefit from unioning the tables before counting. e.g.
select id, count() as count from
(select id from table1
union all
select id from table2)
I'm not sure if I understand completely but you seem to be asking about a UNION
SELECT A,B
FROM tableX
UNION ALL
SELECT A,B
FROM tableY
To do it, you would go:
SELECT * INTO TABLE3 FROM TABLE1
UNION
SELECT * FROM TABLE2
Provided both tables have the same columns
I think what you are looking for is this, but I am not sure I am understanding your language correctly.
select id, sum(count) as count
from (
select id, count() as count
from table1
union all
select id, count() as count
from table2
) a
group by id
Here is my situation:
Table one contains a set of data that uses an id for an unique identifier. This table has a one to many relationship with about 6 other tables such that.
Given Table 1 with Id of 001:
Table 2 might have 3 rows with foreign key: 001
Table 3 might have 12 rows with foreign key: 001
Table 4 might have 0 rows with foreign key: 001
Table 5 might have 28 rows with foreign key: 001
I need to write a report that lists all of the rows from Table 1 for a specified time frame followed by all of the data contained in the handful of tables that reference it.
My current approach in pseudo code would look like this:
select * from table 1
foreach(result) {
print result;
select * from table 2 where id = result.id;
foreach(result2) {
print result2;
}
select * from table 3 where id = result.id
foreach(result3) {
print result3;
}
//continued for each table
}
This means that the single report can run in the neighbor hood of 1000 queries. I know this is excessive however my sql-fu is a little weak and I could use some help.
LEFT OUTER JOIN Tables2-N on Table1
SELECT Table1.*, Table2.*, Table3.*, Table4.*, Table5.*
FROM Table1
LEFT OUTER JOIN Table2 ON Table1.ID = Table2.ID
LEFT OUTER JOIN Table3 ON Table1.ID = Table3.ID
LEFT OUTER JOIN Table4 ON Table1.ID = Table4.ID
LEFT OUTER JOIN Table5 ON Table1.ID = Table5.ID
WHERE (CRITERIA)
Join doesn't do it for me. I hate having to de-tangle the data on the client side. All those nulls from left-joining.
Here's a set-based solution that doesn't use Joins.
INSERT INTO #LocalCollection (theKey)
SELECT id
FROM Table1
WHERE ...
SELECT * FROM Table1 WHERE id in (SELECT theKey FROM #LocalCollection)
SELECT * FROM Table2 WHERE id in (SELECT theKey FROM #LocalCollection)
SELECT * FROM Table3 WHERE id in (SELECT theKey FROM #LocalCollection)
SELECT * FROM Table4 WHERE id in (SELECT theKey FROM #LocalCollection)
SELECT * FROM Table5 WHERE id in (SELECT theKey FROM #LocalCollection)
Ah! Procedural! My SQL would look like this, if you needed to order the results from the other tables after the results from the first table.
Insert Into #rows Select id from Table1 where date between '12/30' and '12/31'
Select * from Table1 t join #rows r on t.id = r.id
Select * from Table2 t join #rows r on t.id = r.id
--etc
If you wanted to group the results by the initial ID, use a Left Outer Join, as mentioned previously.
You may be best off to use a reporting tool like Crystal or Jasper, or even XSL-FO if you are feeling bold. They have things built in to handle specifically this. This is not something the would work well in raw SQL.
If the format of all of the rows (the headers as well as all of the details) is the same, it would also be pretty easy to do it as a stored procedure.
What I would do: Do it as a join, so you will have the header data on every row, then use a reporting tool to do the grouping.
SELECT * FROM table1 t1
INNER JOIN table2 t2 ON t1.id = t2.resultid -- this could be a left join if the table is not guaranteed to have entries for t1.id
INNER JOIN table2 t3 ON t1.id = t3.resultid -- etc
OR if the data is all in the same format you could do.
SELECT cola,colb FROM table1 WHERE id = #id
UNION ALL
SELECT cola,colb FROM table2 WHERE resultid = #id
UNION ALL
SELECT cola,colb FROM table3 WHERE resultid = #id
It really depends on the format you require the data in for output to the report.
If you can give a sample of how you would like the output I could probably help more.
Join all of the tables together.
select * from table_1 left join table_2 using(id) left join table_3 using(id);
Then, you'll want to roll up the columns in code to format your report as you see fit.
What I would do is open up cursors on the following queries:
SELECT * from table1 order by id
SELECT * from table1 r, table2 t where t.table1_id = r.id order by r.id
SELECT * from table1 r, table3 t where t.table1_id = r.id order by r.id
And then I would walk those cursors in parallel, printing your results. You can do this because all appear in the same order. (Note that I would suggest that while the primary ID for table1 might be named id, it won't have that name in the other tables.)
Do all the tables have the same format? If not, then if you have to have a report that can display the n different types of rows. If you are only interested in the same columns then it is easier.
Most databases have some form of dynamic SQL. In that case you can do the following:
create temporary table from
select * from table1 where rows within time frame
x integer
sql varchar(something)
x = 1
while x <= numresults {
sql = 'SELECT * from table' + CAST(X as varchar) + ' where id in (select id from temporary table'
execute sql
x = x + 1
}
But I mean basically here you are running one query on your main table to get the rows that you need, then running one query for each sub table to get rows that match your main table.
If the report requires the same 2 or 3 columns for each table you could change the select * from tablex to be an insert into and get a single result set at the end...