I want to retrieve column values of Name from 3 different tables
Table1 contains Name
Table2 contains Name, BAmt
Table3 contains Name, RAmt
Now I want to fetch names from all the 3 tables.
Let's say the table contains these values
Table1: Table2: Table3:
Name Name BAmt Name RAmt
1. Jack 1.Alice 1000 1.Mark 5000
2. Mark 2.Jack 500 2.Tarzon 1000
3. Ricky 3.Beth 5500
4.Jack 100
Now I want a table that contains all the names (without any repeats of any name). New table should ideally contain these values
Name BAmt RAmt
1.Jack 500 100
2.Mark 5000
3.Ricky
4.Alice 1000
5.Tarzon 1000
6.Beth 5500
Here it has ignored repeats but has taken the necessary values of those columns from the table.
What kind of a select statement should I use.
Here is something I think, but I guess its wrong approach:
Statement statement1 = db.createStatement("SELECT DISTINCT Name,BAmt,RAmt FROM Table1,Table2,Table3");
statement1.prepare();
statement1.execute();
Please guide.
You will need to union all all your tables to get that outline:
select Name,
ifnull (sum(BAmt), 0) BAmt,
ifnull (sum(RAmt), 0) RAmt
from
(
select Name,
null BAmt,
null RAmt
from Table1
union all
select Name,
BAmt,
null
from Table2
union all
select Name,
null,
RAmt
from Table3
) allTables
group by Name
order by Name
EDIT: updated to replace nulls with zeros.
See Documentation for ifnull.
The Join will take care of it:
select name, bamt, ramt from table1 t1 left outer join table2 t2 on t1.name = t2.name left outer join table3 on t1.name = t3.name order by name;
Related
I have two tables that have more than three fields each. There is a group of records that are on both files, the below is a mock example:
Table 1:
ID Name Town State
1 Dave Chicago IL
2 Mark Tea MD
Table 2:
ID Name State Job Married
1 Dave IL Manager Yes
2 Mark MD Driver No
For my purpose duplicates exist if ID, Name, and State are the same. So the above data are duplicates. How do I delete them from one table (I have over 900 duplicates so deleting one by one is not possible)?
delete table1
where ID in(select distinct ID from table1 where ID in (Select ID from table2))
i dont understand which table has duplicates, if you want to delete duplicate data from one table1 then you can use this query
This query will produce a de-duplicated result set:
SELECT Table1.ID,
Table1.NAME,
Table1.Town,
Table1.STATE,
NULL AS Job,
NULL AS Married
FROM Table1
WHERE Table1.ID NOT IN (
SELECT Table1.ID
FROM Table1
INNER JOIN Table2 ON (Table2.STATE = Table1.STATE)
AND (Table2.NAME = Table1.NAME)
AND (Table1.ID = Table2.ID)
)
UNION
SELECT Table2.ID,
Table2.NAME,
NULL AS Town,
Table2.STATE,
Table2.Job,
Table2.Married
FROM Table2
This is the most straightforward way to do it, assuming that you want to delete from Table1. I'm a little rusty with Access SQL syntax, but I believe this works:
DELETE FROM [Table1]
WHERE EXISTS (
SELECT 1
FROM [Table2]
WHERE [Table2].[ID] = [Table1].[ID]
AND [Table2].[Name] = [Table1].[Name]
AND [Table2].[State] = [Table1].[State]
)
I have 2 tables. One table lists all the records of items we track. The other table contains flags of attributes of the records in the first table.
For example, Table 1 has columns
Tab1ID, Name, Address, Phone
Table 2 has these columns
Tab2ID, Tab1ID, FlagName
There is a 1 to Many relationship between Table1 and Table2 linked by Tab1ID.
I'd like to create a query that has all the records from Table1 in it. However, if one of the records in Table2 has a Flagname=Retired (with a matching Tab1ID) then I want a "Y" to show up in the select column list otherwise an "N".
I think it might look something like this:
Select Name, Address, Phone, (select something in table2)
from Table1
where Tab1ID > 1;
It's the subquery in the column that has me stumped.
Pat
You can use exists:
Select t1.*,
(case when exists (select 1
from table2 t2
where t2.tab1id = t1.tab1id and t2.flagname = 'Retired'
)
then 'Y' else 'N'
end) as retired_flag
from Table1 t1;
I would do a normal join returning multiple records, but convert them to bits with case statements. Then use that as the subquery and pull the max value for each bit column.
select
name
,address
,phone
,max(retired_flag)
from (
select
table1.name
,table1.address
,table1.phone
,case when table2.flagname = 'retired' then 1 else 0 end as [retired_flag]
from table1
left join table2
on table1.tab1id = table2.tab1id
where tab1id > 1
) tbl
group by
name
,address
,phone
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
Alright let me explain my question with example
We have 1 table
This table contains
Id
Name
Number
Now example
1 House 4
2 Hospital 3
3 Airport 1
4 Station 2
Now when fetching as select * from table
I want to replace third column number values with that number representing Name
So example of fetching
1 House Station
2 Hospital Airport
3 Airport House
4 Station Hospital
How can i do this ? thank you
select t1.id,
t1.name,
t2.name as name2
from your_table t1
left join your_table t2 on t1.number = t2.id
You can join the same table twice to replace the number with the name. The on contidion in the join matches the table again and then you can select the name from that table (t2)
SQLFiddle Example
You can do this with an explicit join:
select t.id, t.name, t2.name as otherName
from t left outer join
t t2
on t2.number = t.id
I have two tables with the same structure:
id name
1 Merry
2 Mike
and
id name
1 Mike
2 Alis
I need to union second table to first with keeping unique names, so that result is:
id name
1 Merry
2 Mike
3 Alis
Is it possible to do this with MySQL query, without using php script?
This is not a join (set multiplication), this is a union (set addition).
SELECT #r := #r + 1 AS id, name
FROM (
SELECT #r := 0
) vars,
(
SELECT name
FROM table1
UNION
SELECT name
FROM table2
) q
This will select all names from table1 and combine those with all the names from table2 which are not in table1.
(
select *
from table1
)
union
(
select *
from table2 t2
left join table1 t1 on t2.name = t1.name
where t1.id is null
)
Use:
SELECT a.id,
a.name
FROM TABLE_A a
UNION
SELECT b.id,
b.name
FROM TABLE_B b
UNION will remove duplicates.
As commented, it all depends on what your 'id' means, cause in the example, it means nothing.
SELECT DISTINCT(name) FROM t1 JOIN t2 ON something
if you only want the names
SELECT SUM(something), name FROM t1 JOIN t2 ON something GROUP BY name
if you want to do some group by
SELECT DISTINCT(name) FROM t1 JOIN t2 ON t1.id = t2.id
if the id's are the same
SELECT DISTINCT COALESCE(t1.name,t2.name) FROM
mytable t1 LEFT JOIN mytable t2 ON (t1.name=t2.name);
will get you a list of unique names from the 2 tables. If you want them to get new ids (like Alis does in your desired results), that's something else and requires the answers to a couple of questions:
do any of the names need to maintain their previous id. And if they do, which table's id should be preferred?
why do you have 2 tables with the same structure? ie what are you trying to accomplish when you generate the unique name list?