I have a database with 2 tables. table1 and table2.
Table1 contains a list of tests ( column 'name' ). And I want to count how many rows are missing in table2 ( this table has also a column 'name' ) according to the list of tests of table1.
So I just want to count the mismatch between table1.name and table2.name.
I tried several querys, but all didnt really work.
I tried to use the 'NOT IN' statement but it takes too much time. Like several minutes.
For example, the output should be :
COUNT(*) = 20
It means that 20 tests are missing ( or not done yet ) in table2.
I'm using MySQL, so I can't use EXCEPT or MINUS statement.
Thank you by advance.
Nordine
You can use not exists :
select count(*)
from table1 t1
where not exists (select 1 from table2 t2 where t2.name = t1.name);
If you have a duplicate name in table1 then you need count(distinct t1.name) instead.
Try the below query:
select count(case when bname is null then 1 end)
from
(
select a.name as aname, b.name as bname from
table1 a left join table2 b
on a.name=b.name)x
MINUS can be used in MySQL.
Ref:http://www.mysqltutorial.org/mysql-minus/
Try this:
SELECT name
FROM table1
MINUS
SELECT name
FROM table2
Related
I have 2 sql table as follows:
First table t1:
Second table t2:
I need to calculate the count of "Number" column based on "Name" column from t1 and merge it with t2.
I wrote following code. But it seems not working
select *
from (
select Name, count(Number) as count
from t1
group by Name ) as a
join ( select *
from t2 ) as b
on a.Name = b.Name;
Can any one figure out what is wrong ? Thank you very much
I think you want to use SUM() instead of COUNT().
Because SUM() sums some integers, while COUNT() counts number of occurencies.
And as also stated in the comments, multiple columns with same names will create conflicts, so you have to select the wanted columns explicit (that is usually a good idea anyway).
You could obtain your wanted endgoal by this query:
select
SUM(Number),
t1.Name,
(select val1 FROM t2 WHERE t2.Name = t1.Name LIMIT 1) as val1
FROM t1
GROUP BY t1.Name
Example in sqlfiddle: http://sqlfiddle.com/#!9/04dddf/7
I need to join two tables in SQL. There are no common fields. But the one table have a field with the value krin1001 and I need it to be joined with the row in the other table where the value is 1001.
The idea behind the joining is i have multiple customers, but in the one table there customer id is 'krin1001' 'krin1002' and so on, in this table is how much they have sold. In the other table there customer is is '1001' '1002' and so on, and in this table is there name and adress and so on. So it will always be the first 4 charakters i need to strip from the field before matching and joining. It might not always be 'krin' i need it to work with 'khjo1001' also, and it still needs to join on the '1001' value from the other table.
Is that possible?
Hope you can help me.
You need to use substring:
ON SUBSTRING(TableA.Field, 5, 4) = TableB.Field
Or Right:
ON RIGHT(TableA.Field, 4) = TableB.Field
You can also try to use CHARINDEX function for join operation. If value from table1 contains value from table2 row will be included in result set.
;WITH table1 AS(
SELECT 'krin1001' AS val
UNION ALL
SELECT 'xxx'
UNION ALL
SELECT 'xyz123'
),
table2 AS(
SELECT '1001' AS val
UNION ALL
SELECT '12345'
UNION ALL
SELECT '123'
)
SELECT * FROM table1 AS t
JOIN table2 AS T2 ON CHARINDEX(T2.val, T.val) > 0
Use it as:
SELECT
*
FROM table t1
INNER JOIN table t2 ON RIGHT(t1.col1, 4) = t2.col1;
Have a table where certain rows come in couples which have a matching GUID. Just wondering how to SELECT all data from the table but ONLY if the rows exist as a couple with a matching GUID.
You can use a query like this:
SELECT *
FROM yourtable
WHERE GUID IN (SELECT GUID FROM yourtable GROUP BY GUID HAVING COUNT(*)=2)
The subquery will return all GUIDs that appears exactly twice, the outer query will return all rows associated to those GUIDs.
Please see fiddle here.
Try something like this:
SELECT t1.*
FROM
table t1
, table t2
WHERE
t1.guid = t2.guid
AND t1.id <> t2.id
;
table: your table name
id: some field that you know is different for both rows
Try
SELECT t.*
FROM Table1 t JOIN
(
SELECT guid
FROM Table1
GROUP BY guid
HAVING COUNT(*) = 2
) q ON t.guid = q.guid
Here is SQLFiddle demo
I'm desperate with this query. I have two tables table1 and table2, tables are identical but they have different data. I'm trying to remove duplicities by columns code and manufacturer. To do that I need in final result ID from table1 ID from table2 and also columns code and manufacturer
SELECT * FROM (
SELECT id,code,manufacturer FROM table1 WHERE manufacturer = 1
UNION SELECT id,code,manufacturer FROM table2 WHERE manufacturer = 1
) AS t GROUP BY code HAVING COUNT(*) > 1
But in result i got only values from table1. It's OK but I just need to get there id from table2 too. Please can anyone give me some tips how to do this ?
You have two basic problems:
Problem 1:
You are using UNION when you should be using UNION ALL, because UNION removes duplicates!
Problem 2:
This isn't the right way to go about the problem. You should be using a simple join, not a union.
Try this:
SELECT
t1.id as table1_id,
t2.id as table2_id,
t1.code,
t1.manufacturer
FROM table1 t1
JOIN table2 t2
ON t2.code = t1.code
AND t2.manufacturer = t1.manufacturer
WHERE manufacturer = 1 -- this WHERE clause is optional
Your use of the WHERE clause is a little odd - consider removing it to get all duplicates from all manufacturers.
I was making a query for search but the result should be obtained from three tables and it works fine for only two characters after that it returns empty rows so can anyone help please
here is my query
SELECT *
FROM tables
WHERE table2_id
IN (
SELECT id
FROM table2
WHERE table3_id
IN (
SELECT id
FROM table3
WHERE name LIKE '%in%'
)
OR
)
name LIKE 'in%'
AND id <> '8'
Any suggestions if I am making the right things and what went wrong when its more than two characters
That's a completely ridiculous query! Use a join - that's what it's for!
SELECT tables.*
FROM tables JOIN table2 ON tables.table2_id = table2.id
JOIN table3 ON table2.table3_id = table3.id
WHERE (name LIKE '%in%' OR name LIKE 'in%' AND id <> 8