i am using MYSQL..
I have two tables:
TABLE 1 (TABLE NAME T1)
SL NAME
1 a
2 b
3 c
4 c
table 2 (table name T2)
SL NAME
1 a
2 c
3 c
4 c
Q1: how i count the total number of 'c' in both table?
Q2: which name is max occurrences in both table?
sl is primary key...
my query is:>
select count(*) from t1,t2
where t1.name=t2.name where t1.name='c';
but it showing 6
To count c in both tables you should use UNION, not JOIN.
Syntax:
SELECT ...
UNION [ALL | DISTINCT] SELECT ...
[UNION [ALL | DISTINCT] SELECT ...]
Doc:
http://dev.mysql.com/doc/refman/5.0/en/union.html
Edit:
I'll explain the query that you provided.
select count(*) from t1,t2 where t1.name=t2.name where t1.name='c';
First of all, you use WHERE clause twice which is a syntax error. Should be:
select count(*) from t1,t2 where t1.name=t2.name AND t1.name='c';
And this is the same that:
SELECT count(*) from t1
JOIN t2 ON t1.name=t2.name
WHERE t1.name='c';
You choose only rows with c value so these are the rows, that we will take under consideration:
TABLE 1 (TABLE NAME T1)
SL NAME
3 c
4 c
table 2 (table name T2)
SL NAME
2 c
3 c
4 c
Now, simple JOIN joins every row from table 1 to every row from table 2 (where condition is true of course)
So the result before counting is:
t1.SL t1.NAME t2.SL t2.NAME
3 c 2 c
4 c 3 c
3 c 4 c
4 c 2 c
3 c 3 c
4 c 4 c
This is 6 rows.
Answers for both of your questions.
SELECT name, count(*) as cnt
FROM(select t1.name from t1
union all
select name from t2) as tem
group by name
order by cnt DESC
This query will give you ranking of names ordered by occurrences.
To retrieve only c count, just add WHERE clause. To retrieve only the most occurring name set LIMIT clause to 1.
INSERT INTO #test
SELECT NAME FROM m_t1 WHERE NAME ='c'
UNION all
SELECT NAME FROM m_t2 WHERE NAME ='c'
SELECT count(*) FROM #test
Related
i have two tables as below:
firsttable
id
cat_id
name
1
2
name_01
2
2
name_02
3
1
name_03
4
3
name_04
5
3
name_04
secondtable
id
name
1
cat_01
2
cat_02
3
cat_03
my question is how can i create below table result?
id(secondtable)
name(secondtable)
count(firsttable)
1
cat_01
1
2
cat_02
2
3
cat_03
2
select t2.id,t2.name,
(select count(*) from firsttable t1 where t1.cat_id=t2.id )as count
from secendtable t2;
Just using standard aggregation
select
s.id,
s.name,
count(*)
from firsttable f
join secondtable s
on f.cat_id = s.id
group by s.id, s.name order by s.id
It's very Simple like that
SELECT s.id,s.name, (SELECT count(*)
FROM `firsttable` AS f
WHERE f.cat_id = s.id ) as count
FROM `secondtable` AS s
I have the table 'Table01' which contains the keys that should be mandatory:
id
1
2
3
4
And I also have the table 'Table02' which contains the records to be filtered:
id
customer
weight
1
a
100
2
a
300
3
a
200
4
a
45
1
b
20
2
b
100
3
b
17
1
c
80
4
c
90
2
d
30
3
d
30
4
d
50
So I want to identify which are the mandatory id's that the table 'Table02' does not have, and in turn identify which is the 'customer' of each id's that the table 'Table02' does not have.
The resulting table should look like this:
customer
id
b
4
c
2
c
3
d
1
What I have tried so far is a 'rigth join'.
proc sql;
create table table03 as
select
b.id
from table02 a
right join table01 b
on a.id=b.id
where a.id is null;
run;
But that query is not identifying all the id's that should be mandatory.
I hope someone can help me, thank you very much.
here is one way:
select cl.customerid , a.id
from
Table1 a
cross join
( select customerid
from table2
group by customerid
) cl
where not exists ( select 1 from table2 b
where b.customerid = cl.customerid
and b.id = a.id
)
You can use an EXCEPT between two sub-selects. The first creates a matrix of all possibilities, and the except table is a selection of the extant customers.
Example:
data ids;
do id = 1 to 4; output; end;
run;
data have;
input id customer $ weight;
datalines;
1 a 100
2 a 300
3 a 200
4 a 45
1 b 20
2 b 100
3 b 17
1 c 80
4 c 90
2 d 30
3 d 30
4 d 50
run;
proc sql;
create table want(label='Customers missing some ids') as
select matrix.*
from
(select distinct have.customer, ids.id from have, ids) as matrix
except
(select customer, id from have)
;
quit;
If you are doing it in SQL server. Something like #eshirvana above posted, but also you can use with cte:
;with cte as
(
SELECT t1.id, t2.Customer
FROM Table01 t1
cross join (select distinct customer from Table02)
)
SELECT a.customer, a.id FROM cte a
LEFT JOIN Table02 b
ON a.id=b.id AND a.customer=b.customer
where b.id is null
I have a three tables
Table 1
Id Department
1 A
2 B
3 C
4 D
Table 2
Id DepartId Name
1 1 ABC
2 1 DEF
3 1 ASD
4 2 FGH
5 2 HJK
6 3 ZXC
Table 3
Id Depart Area
1 A pp
2 B
3 C nn
4 D oo
I need the result
Id Depart Name Area
1 A ABC pp
2 B FGH Null
3 C ZXC nn
4 D NULL oo
I need one matching entry from table 2 and table 3 to corresponding entry in the table 1
Do a left join to also get t1 rows without any reference in the t2 table. GROUP BY to get only 1 row per Department.
select t1.id, t1.Department, min(t2.Name)
from t1
left join t2 on t1.id = t2.DepartId
group by t1.id, t1.Department
I think I would do this with a correlated subquery:
select t1.*,
(select t2.name
from t2
where t1.id = t2.DepartId and rownum = 1
) as t2name
from t1;
This saves the overhead of an aggregation. An index on t2(DepartId, name) is optimal for this query.
by the way not the answer to your specific question but if instead of just one you want all the names you can use listagg
SELECT t1.id,
department,
LISTAGG (name, ',') WITHIN GROUP (ORDER BY name) names
FROM t1, t2
WHERE t1.id = t2.departId(+)
GROUP BY t1.id, department
ORDER BY 1
ID Department Names
1 A ABC,ASD,DEF
2 B FGH, HJK
3 C ZXC
4 D
I have two tables with this values:
**table 1**
id name value
1 A 1
2 B 1
3 F 2
4 G 3
**table 2**
id name value
1 C 1
2 D 1
3 E 2
If I do an inner join of both tables by the value I´m getting this:
A C
A D
B C
B D
F E
But, the problem is that I want only distinct values from both columns like that:
A C
B D
F E
Another set of posible result will be:
A D
B C
F E
There´s no chance of name of table 1 will appear in table 2.
If one value from a column was already selected, it can´t be selected again. This example will be an error because C was already selected:
A C
B C
F E
Any ideas?
In order to pair the records, you need a running number per value to link with. Use row_number() for this.
select t1.name as t1_name, t2.name as t2_name
from
(
select name, value, row_number() over (partition by value order by name) as rn
from table1
) t1
join
(
select name, value, row_number() over (partition by value order by name) as rn
from table2
) t2
on t1.value = t2.value and t1.rn = t2.rn;
SQL fiddle: http://www.sqlfiddle.com/#!4/75de0/1.
Based on the data you provided, and the column you're using to join, you're getting the results you should be getting.
To get your desired results, you would need to join on id, not value
as such:
select a.id, a.name, b.name
from tableA a
inner join tableB b on a.id = b.id
I have the following tables in a Hive database:
table1:
id t X
1 1 a
1 4 a
2 5 a
3 10 a
table2:
id t Y
1 3 b
2 6 b
2 8 b
3 15 b
And I would like to merge them to have a table like:
id t Z
1 1 a
1 3 b
1 4 a
2 5 a
2 6 b
2 8 b
3 10 a
3 15 b
Basically what I want to do is :
a join on the column id (that part is easy)
merge the columns table1.t and table2.t into a new column t
have the variable Z that is equal to table1.X if the corresponding t comes from table1.t, and table2.Y if it comes from table2.t
order the table by id and then by t (that shouldn't be too hard)
I have no idea on how to do the parts 2 and 3. I tried with an outer join on
table1.id = table2.id and table1.t = table2.t, but it doesn't merge the two columns t.
Any pointer would be appreciated. Thanks!
CREATE TABLE table3 as SELECT * FROM (SELECT id,t,X as Z FROM t3_1 UNION ALL SELECT id,t,Y as Z FROM t3_2) u1 order by id,t;
Although not always required, using a subquery for the union'd queries help to organize, plus you can then reference the fields from the union (e.g. u1.id ) in other parts of the query.
You'll need the alias on the 3rd column to make the schemas match. If the source table name was not already a column, you could do something like this:
select * from (select id,t,'a' from t3_1 UNION ALL select id,t,'b' from t3_2) u1;
Try this one. It will insert in table 3, all the values from the other 2 tables
INSERT INTO table3 ( t, Z )
SELECT t, X
FROM table1
UNION ALL
SELECT t, Y
FROM table2