I'm currently trying to update an existing database (removing duplicates).
You can see the structure as follows :
I have a database on which specific entries are marked as "Main". These entries need to be updated with data from duplicate records, only having the same name.
(Updated table to reflect my question better)
It would look like this:
+----+------+-----------------+--------------+---------+
| ID | Name | Field-To-Update | Duplication | Source |
+----+------+-----------------+--------------+---------+
| . | A | xxx | Main | 1 |
| . | A | yyy | "" | 2 |
| . | A | zzz | "" | 3 |
| . | B | foo | "" | 1 |
| . | B | bar | Main | 2 |
+----+------+-----------------+--------------+---------+
Should result in
+----+------+-----------------+--------------+-----------------------------------------------+
| ID | Name | Field-To-Update | Duplication | Source |
+----+------+-----------------+--------------+-----------------------------------------------+
| . | A | yyy | Main | 1 |
| . | A | yyy | "" | 2 |
| . | A | zzz | "" | 3 (should be updated from a specific source) |
| . | B | bar | "" | 1 |
| . | B | bar | Main | 2 (should be updated from a specific source) |
+----+------+-----------------+--------------+-----------------------------------------------+
Do any of you have an idea how to tackle this? I've tried with multiple queries for a couple of days now without any success.
you could use a update with join
update t
set t.field_to_update = x.field_to_update
from your_table t
inner join ( select name, field_to_update
from your_table
where Duplication <> 'Main') x
) on t.name = x.name
where t.Duplication = 'Main'
Bizarre requirement. You say you are updating to remove duplicates, however, it looks to me like you are creating duplicates.
There are only 2 records for each Name? Try:
UPDATE Table INNER JOIN
(SELECT Name, [Field-To-Update]
FROM Table
WHERE Duplication Is Null) AS Query1 ON
Table.Name = Query1.Name SET Table.[Field-To-Update] = [Query1]![Field-To-Update] WHERE Duplication = "Main";
Name is a reserved word in Access. Should not use reserved words as name for anything.
Darn! Did not see #scaisEdge answer before posting.
I tried the <> "Main" criteria and it did not work which was surprising - no records returned. So I switched to the Is Null parameter.
If you want to pull value from the maximum Source for each Name, then need a query that does that. Review http://allenbrowne.com/subquery-01.html#TopN. Then use that query in the above example as Query1.
Related
In the example below, I'm trying to create a query that returns the content of NAME if this contains both 'ammonium nitrate' and 'urea'. The thing is, they are in separate rows and I haven't found how to check for both. I've tried using the clauses IN, AND, and UNION, but to no avail.
The query should return only 'Gro-Fast', as it is the only NAME that contains both.
+-------+------------------+-------------+---------+
| FCODE | CNAME | NAME | CONTACT |
+-------+------------------+-------------+---------+
| 28994 | ammonium nitrate | Gro-Fast | 556698 |
| 28994 | urea | Gro-Fast | 556698 |
| 29462 | ammonium nitrate | BetterRoots | 342554 |
| 34588 | ammonium nitrate | Flourisher | 342554 |
| 83732 | urea | GreenAgain | 354211 |
+-------+------------------+-------------+---------+
TIA!
You can group by name and set the conditions in the HAVING clause:
select name
from tablename
where cname in ('ammonium nitrate', 'urea')
group by name
having count(distinct cname) = 2
If you want the column cnameto contain only 'ammonium nitrate' and 'urea':
select name
from tablename
group by name
having
sum(cname not in ('ammonium nitrate', 'urea')) = 0
and
count(distinct cname) = 2
See the demo.
Results:
> | name |
> | :------- |
> | Gro-Fast |
Edit, for your query:
select name
from CONTENTS natural join FERTILIZERS
where cname in ('ammonium nitrate', 'urea')
group by name
having count(distinct cname) = 2
I have a table with this sort of data:
+------------+----------+----------+
| Unique ID | Name | Class |
+------------+----------+----------+
| 1 | Name 1 | Class A |
| 2 | Name 2 | "" |
| 3 | Name 3 | Class C |
| 4 | Name 1 | "" |
| 5 | Name 4 | "" |
| 6 | Name 4 | "" |
+------------+----------+----------+
I am trying to do something I thought was simple, but i did not find so.
I am trying to "extract" only the lines with an empty string value in 'Class' for a group of equal names.
So in this case I would get this result :
+------------+----------+--------+
| Unique ID | Name | Class |
+------------+----------+--------+
| 2 | Name 2 | "" |
| 5 | Name 4 | "" |
+------------+----------+--------+
So not Name 1 because even though there is a line with "" there is another line with 'Class A'.
I thought a UNION would do the job but I am not gettgin anything because I think unions are for two tables but the problem here is I have the data in the same table.
Thank you for your help
Access syntax may be a bit different but this returns what you want in Oracle:
SELECT distinct Name, Class FROM table1 Where Name NOT in (select name from table1 where class is not null)
A Union melds two result sets, whether or not they come from the same table is irrelevant. What you want to do is omit from the result set the rows with the same name AND class is not null. Not having your query to expand on or change is a problem, but if you add a clause that says something like where "name not in (select name from table where class is not null);", that may do it.
I want to select value from table sorted by a certain order.
I have a table called test that looks like this:
| date | code | value |
+----------+-----------+----------+
| 20050104 | 000005.SZ | -6359.19 |
| 20050104 | 600601.SH | -7876.34 |
| 20050104 | 600602.SH | -25693.3 |
| 20050104 | 600651.SH | NULL |
| 20050104 | 600652.SH | -15309.9 |
...
| 20050105 | 000005.SZ | -4276.28 |
| 20050105 | 600601.SH | -3214.56 |
...
| 20170405 | 000005.SZ | 23978.13 |
| 20170405 | 600601.SH | 32212.54 |
Right now I want to select only one date, say date = 20050104, and then sort the data by a certain order (the order that each stock was listed in the stock market).
I have another table called stock_code which stores the correct order:
+---------+-----------+
| code_id | code |
+---------+-----------+
| 1 | 000002.SZ |
| 2 | 000004.SZ |
| 3 | 600656.SH |
| 4 | 600651.SH |
| 5 | 600652.SH |
| 6 | 600653.SH |
| 7 | 600654.SH |
| 8 | 600602.SH |
| 9 | 600601.SH |
| 10 | 000005.SZ |
...
I want to sorted the selected data by stock_code(code_id), but I don't want to use join because it takes too much time. Any thoughts?
I tried to use field but it gives me an error, please tell me how to correct it or give me an even better idea.
select * from test
where date = 20050104 and code in (select code from stock_code order by code)
order by field(code, (select code from stock_code order by code));
Error Code: 1242. Subquery returns more than 1 row
You told us that you don't want to join because it takes too much time, but the following join query is probably the best option here:
SELECT t.*
FROM test t
INNER JOIN stock_code sc
ON t.code = sc.code
WHERE t.date = '20050104'
ORDER BY sc.code_id
If this really runs slowly, then you should check to make sure you have indices setup on the appropriate columns. In this case, indices on the code columns from both tables as well as an index on test.date should be very helpful.
ALTER TABLE test ADD INDEX code_idx (code)
ALTER TABLE test ADD INDEX date_idx (date)
ALTER TABLE code ADD INDEX code_idx (code)
I have these tables in my MySQL database:
General table:
+----generalTable-----+
+---------------------+
| id | scenario | ... |
+----+----------+-----+
| 1 | facebook | ... |
| 2 | chief | ... |
| 3 | facebook | ... |
| 4 | chief | ... |
Facebook Table:
+----facebookTable-----+
+----------------------+
| id | expiresAt | ... |
+----+-----------+-----+
| 1 | 12345678 | ... |
| 3 | 45832458 | ... |
Chief Table:
+------chiefTable------+
+----------------------+
| id | expiresAt | ... |
+----+-----------+-----+
| 2 | 43547343 | ... |
| 4 | 23443355 | ... |
Basically, the general table holds some (obviously) general data. Based on the generalTable.scenario you can look up more details in the other two tables, which are in some columns familiar (expiresAt for example) but in others not.
My question is, how to get the joined data of generalTable and the right detailed table in just one query.
So, I would like a query like this:
SELECT id, scenario, expiresAt
FROM generalTable
JOIN facebookTable
ON generalTable.id = facebookTable.id
JOIN chiefTable
ON generalTable.id = chiefTable.id
And an output like this:
| id | scenario | expiresAt |
+----+----------+-----------+
| 1 | facebook | 12345678 |
| 2 | chief | 43547343 |
| 3 | facebook | 45832458 |
| 4 | chief | 23443355 |
However, this doesn't work, because both facebookTable and chiefTable have ambiguous column name "expiresAt". For the ease of use I want to keep it that way. The result table should also only have one column "expiresAt" that is automatically filled with the right values from either facebookTable or chiefTable.
You might want to consider adding expiredAt to your general table, and removing it from the others, to remove duplication in the schema, and to make this particular query simpler.
If you need to stick with your current schema, you can use table aliases to resolve the name ambiguity, and use two joins and a union to create the result you are looking for:
SELECT g.id, g.scenario, f.expiresAt
FROM generalTable g
JOIN facebookTable f
ON g.id = f.id
UNION ALL
SELECT g.id, g.scenario, c.expiresAt
FROM generalTable g
JOIN chiefTable c
ON g.id = c.id;
The outer join approach mentioned in another answer would also solve the problem.
One way you could accomplish it is with LEFT JOIN. In the result fields you can do something like this for common fields IF(fTbl.id IS NULL, cTbl.expiresAt, fTbl.expiresAt) AS expiresAt.
I have two tables.
rp_format
+-----+--+--------------+
| fid | | recordformat |
+-----+--+--------------+
| 1 | | CD |
| 2 | | Vinyl |
| 3 | | DVD |
+-----+--+--------------+
rp_records
+----+--+--------+
| id | | format |
+----+--+--------+
| 1 | | 1 |
| 2 | | 2 |
| 3 | | 3 |
+----+--+--------+
What I would like to achieve is to display everything from "rp_format". But I would also like make a check to see if there is a "fid"-value found in "format".
Example that should be displayed on page like this:
fid recordformat
1 CD Remove this format
2 Vinyl Remove this format
3 DVD Remove this format
But let's say an "fid" value is found in "format" then I would like it to be displayed like this on page:
fid recordformat
1 CD Remove this format
2 Vinyl Can't remove this format
3 DVD Remove this format
"Remove this format / Can't remove this format" is text that will be displayed by checking if "fid" = "format" using PHP.
Here is my SQL query so far:
global $wpdb;
$rpdb = $wpdb->prefix . 'rp_format';
$rpdb2 = $wpdb->prefix . 'rp_records';
$sql = "
SELECT *
FROM $rpdb
LEFT OUTER JOIN $rpdb2 ON $rpdb.fid = $rpdb2.format
UNION
SELECT *
FROM $rpdb
RIGHT OUTER JOIN $rpdb2 ON $rpdb.fid = $rpdb2.format
WHERE $rpdb.fid IS NOT NULL
";
The issue I have with this query is that when "fid" is found in "format" (let's say it's found 10 times) every of these 10 values will be outputed also.
How can this be fixed?
Kind regards
Johan
If I understand correctly you want to display some message depending on if the data exists on rp_records or not and avoid multiple display.
Consider the following
mysql> select * from rp_format;
+------+--------------+
| fid | recordformat |
+------+--------------+
| 1 | CD |
| 2 | Vinyl |
| 3 | DVD |
| 4 | Test |
+------+--------------+
4 rows in set (0.00 sec)
mysql> select * from rp_records;
+------+--------+
| id | format |
+------+--------+
| 1 | 1 |
| 2 | 2 |
| 3 | 3 |
| 4 | 2 |
| 5 | 1 |
+------+--------+
So the query is
select
f.*,
case
when r.format is not null then 'Can\'t remove' else 'Remove this' end
as message
from rp_format f
left join rp_records r on r.format = f.fid
group by f.fid ;
+------+--------------+--------------+
| fid | recordformat | message |
+------+--------------+--------------+
| 1 | CD | Can't remove |
| 2 | Vinyl | Can't remove |
| 3 | DVD | Can't remove |
| 4 | Test | Remove this |
+------+--------------+--------------+
Not sure that i correctly understand your logic with found and not found format, if i wrong - add to if condition r.format IS NOT NULL instead r.format IS NULL. And i think you no need to use union, you should use join:
SELECT
r.fid,
f.recordformat,
IF(r.format IS NULL, "Can't remove this format", "Remove this format")
FROM rp_format f
LEFT JOIN rp_records r ON f.fid = r.format
GROUP BY f.fid
;
I'm sure that something like this will help you!