My table description is
desc sensor_log_history;
+-------------+-----------------+------+-----+-------------------+-----------------------------+
| Field | Type | Null | Key | Default | Extra |
+-------------+-----------------+------+-----+-------------------+-----------------------------+
| AutoPk | int(4) unsigned | NO | MUL | NULL | |
| sensorName | varchar(20) | NO | | NULL | |
| SensorValue | double(65,2) | NO | | 0.00 | |
| timest | timestamp | NO | | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP |
+-------------+-----------------+------+-----+-------------------+-----------------------------+
4 rows in set (0.00 sec)
My query is
SELECT AutoPk,Result1.sensorName, SensorValue,Result1.timest FROM (SELECT MAX(timest) AS timest, sensorName FROM sensor_log_history GROUP BY sensorName) AS Result1 INNER JOIN sensor_log_history ON Result1.timest = sensor_log_history.timest WHERE Result1.sensorName = sensor_log_history.sensorName;
How to execute this query using hibernate. Hibernate should return a list of objects of type sensor_log_history.?
Simply create a POJO in your JAVA application and map this table to that POJO using hibernate. Then fire HQL query : "FROM ".
Related
I have a one tables in Postgresql and cannot find how to build a query.
The table contains columns nr_serii and deleteing_time. I trying to count nr_serii and substract from this positions with deleting_time.
My query:
select nr_serii , count(nr_serii ) as ilosc,count(deleting_time) as ilosc_delete
from MyTable
group by nr_serii, deleting_time
output is:
+--------------------+
| "666666";1;1 |
| "456456";1;0 |
| "333333";3;0 |
| "333333";1;1 |
| "111111";1;1 |
| "111111";3;0 |
+--------------------+
The part of table with raw data:
+--------------------------------+
| "666666";"2020-11-20 14:08:13" |
| "456456";"" |
| "333333";"" |
| "333333";"" |
| "333333";"" |
| "333333";"2020-11-20 14:02:23" |
| "111111";"" |
| "111111";"" |
| "111111";"2020-11-20 14:08:04" |
| "111111";"" |
+--------------------------------+
And i need substract column ilosc and column ilosc_delete
example:
nr_serii:333333 ilosc:3-1=2
Expected output:
+-------------+
| "666666";-1 |
| "456456";1 |
| "333333";2 |
| "111111";2 |
| ... |
+-------------+
I think this is very simple solution for this but i have empty in my head.
I see what you want now. You want to subtract the number where deleting_time is not null from the ones where it is null:
select nr_serii,
count(*) filter (where deleting_time is null) - count(deleting_time) as ilosc_delete
from MyTable
group by nr_serii;
Here is a db<>fiddle.
I have these two tables that i need to join
fields_data fields
+------------+-----------+------+ +------+-------------+----------+
| relationid | fieldname | data | | name | displayname | position |
+------------+-----------+------+ +------+-------------+----------+
| 2 | ftp | test | | user | Username | top |
| 2 | other | 1234 | | pass | Password | top |
+------------+-----------+------+ | ftp | FTP | top |
| log | Log | top |
| txt | Text | mid |
+------+-------------+----------+
I want to get all the rows from the "fields" table if they have the position "top" AND if a row has a match on name = fieldname from fields_data it should also show the data. This is my join
SELECT
fd.`data`,
fd.`relationid`,
fd.`fieldname`,
f.`name`,
f.`displayname`
FROM `fields` AS f
LEFT OUTER JOIN `fields_data` AS fd
ON fd.`fieldname` = f.`name`
WHERE f.`position`='top' AND (fd.`relationid`='3' OR fd.`relationid` IS NULL)
My problem is that the above query only gives me this result:
+------+------------+-----------+------+-------------+
| data | relationid | fieldname | name | displayname |
+------+------------+-----------+------+-------------+
| NULL | NULL | NULL | user | Username |
| NULL | NULL | NULL | pass | Password |
| NULL | NULL | NULL | log | Log |
+------+------------+-----------+------+-------------+
The field called "ftp" is missing due to it having a relation to "2".. However i still want to display it as result but like the others with NULL in it. And if the SQL query had "fd.relationid='2'" instead of 3 it would give same result, but with the row containing ftp in name, holding data in the three fields.
I hope you get what i mean.. My english is not the best.. Heres the result i want:
with above query containing fd.`relationid`='3'
+------+------------+-----------+------+-------------+
| data | relationid | fieldname | name | displayname |
+------+------------+-----------+------+-------------+
| NULL | NULL | NULL | user | Username |
| NULL | NULL | NULL | pass | Password |
| NULL | NULL | NULL | ftp | FTP |
| NULL | NULL | NULL | log | Log |
+------+------------+-----------+------+-------------+
with above query containing fd.`relationid`='2'
+------+------------+-----------+------+-------------+
| data | relationid | fieldname | name | displayname |
+------+------------+-----------+------+-------------+
| NULL | NULL | NULL | user | Username |
| NULL | NULL | NULL | pass | Password |
| test | 2 | ftp | ftp | FTP |
| NULL | NULL | NULL | log | Log |
+------+------------+-----------+------+-------------+
You want to move the condition to the on clause:
SELECT fd.`data`, fd.`relationid`, fd.`fieldname`, f.`name`, f.`displayname`
FROM `fields` f LEFT OUTER JOIN
`fields_data` fd
ON fd.`fieldname` = f.`name` AND fd.`relationid` = '3'
WHERE f.`position`='top' ;
It is interesting that the semantics of your query and this query are different -- and you found the exact situation: when there is a match on another value, the where clause form filters out the row. This will still keep everything.
As a note, the following also does what you want:
SELECT fd.`data`, fd.`relationid`, fd.`fieldname`, f.`name`, f.`displayname`
FROM `fields` f LEFT OUTER JOIN
(SELECT fd.*
FROM `fields_data` fd
WHERE fd.`relationid` = '3'
) fd
ON fd.`fieldname` = f.`name`
WHERE f.`position` = 'top' ;
I wouldn't recommend writing the query this way, particularly in MySQL (because the subquery is materialized). However, understanding why your version is different from these versions (and why these are the same) is a big step forward in mastering outer joins.
I am casting a real to an int and a float to an int and comparing the two like this:
where
cast(a.[SUM(PAID_AMT)] as int)!=cast(b.PAID_AMT as int)
but i am still getting results where the two are equal. for example:
+-----------+-----------+------------+------------+----------+
| accn | load_dt | pmtdt | sumpaidamt | Bpaidamt |
+-----------+-----------+------------+------------+----------+
| A133312 | 6/7/2011 | 11/28/2011 | 98.39 | 98.39 |
| A445070 | 6/2/2011 | 9/22/2011 | 204.93 | 204.93 |
| A465606 | 5/19/2011 | 10/19/2011 | 560.79 | 560.79 |
| A508742 | 7/12/2011 | 10/19/2011 | 279.65 | 279.65 |
| A567730 | 5/27/2011 | 10/24/2011 | 212.76 | 212.76 |
| A617277 | 7/12/2011 | 10/12/2011 | 322.02 | 322.02 |
| A626384 | 6/16/2011 | 10/21/2011 | 415.84 | 415.84 |
| AA0000044 | 5/12/2011 | 5/23/2011 | 197.38 | 197.38 |
+-----------+-----------+------------+------------+----------+
here is the full query:
select
a.accn,
a.load_dt,
a.pmtdt,
a.[SUM(PAID_AMT)] sumpaidamt,
sum(b.paid_amt) Bpaidamt
from
[MILLENNIUM_DW_DEV].[dbo].[Millennium_Payment_Data_May2011_July2012] a
join
F_PAYOR_PAYMENTS_DAILY b
on
a.accn=b.ACCESSION_ID
and
a.final_rpt_dt=b.FINAL_REPORT_DATE
and
a.load_dt=b.LOAD_DATE
and
a.pmtdt=b.PAYMENT_DATE
where
cast(a.[SUM(PAID_AMT)] as int)!=cast(b.PAID_AMT as int)
group by
a.accn,
a.load_dt,
a.pmtdt,
a.[SUM(PAID_AMT)]
what am i doing wrong? how do i return only records that are NOT equal?
I don't see why there is an issue.
The query is returning the sum of the payments in b (sum(b.paid_amt) Bpaidamt). The where clause is comparing individual payments. This just means that there is more than one payment.
Perhaps your intention is to have a HAVING clause instead:
having cast(a.[SUM(PAID_AMT)] as int)!=cast(sum(b.PAID_AMT) as int)
You can do a round and a cast statement.
cast(round(sumpaidamt,2) as money) <> cast(round(Bpaidamt,2) as money)
Sql Fiddle showing how it would work http://sqlfiddle.com/#!3/4eb79/1
I am trying to build a new table such that the values in the existing table are NOT contained (but obviously the following checks for contained) in another table. Following is my table structure:
mysql> explain t1;
+-----------+---------------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-----------+---------------------+------+-----+---------+-------+
| id | int(11) | YES | | NULL | |
| point | bigint(20) unsigned | NO | MUL | 0 | |
+-----------+---------------------+------+-----+---------+-------+
mysql> explain whitelist;
+-------------+---------------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------+---------------------+------+-----+---------+----------------+
| id | bigint(20) unsigned | NO | PRI | NULL | auto_increment |
| x | bigint(20) unsigned | YES | | NULL | |
| y | bigint(20) unsigned | YES | | NULL | |
| geonetwork | linestring | NO | MUL | NULL | |
+-------------+---------------------+------+-----+---------+----------------+
My query looks like this:
SELECT point
FROM t1
WHERE EXISTS(SELECT source
FROM whitelist
WHERE MBRContains(geonetwork, GeomFromText(CONCAT('POINT(', t1.point, ' 0)'))));
Explain:
+----+--------------------+--------------------+-------+-------------------+-----------+---------+------+------+--------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+--------------------+--------------------+-------+-------------------+-----------+---------+------+------+--------------------------+
| 1 | PRIMARY | t1 | index | NULL | point | 8 | NULL | 1001 | Using where; Using index |
| 2 | DEPENDENT SUBQUERY | whitelist | ALL | _geonetwork | NULL | NULL | NULL | 3257 | Using where |
+----+--------------------+--------------------+-------+-------------------+-----------+---------+------+------+--------------------------+
The query is taking 6 seconds to execute for 1000 records in t1 which is unacceptable for me. How can I rewrite this query using Joins (or perhaps a faster way if that exists) if I don't have a column to join on? Even a stored procedure is acceptable I guess in the worst case. My goal is to finally create a new table containing entries from t1. Any suggestions?
Unless the query optimizer is failing, a WHERE EXISTS construct should result in the same plan as a join with a GROUP clause. Look at optimizing MBRContains(geonetwork, GeomFromText(CONCAT('POINT(', t1.point, ' 0)')))), that's probably where your query is spending all its time. I don't have a suggestion for that, but here's your query written with a JOIN:
Select t1.point
from t1
join whitelist on MBRContains(whitelist.geonetwork, GeomFromText(CONCAT('POINT(', t1.point, ' 0)'))))
group by t1.point
;
or to get the points in t1 not in whitelist:
Select t1.point
from t1
left join whitelist on MBRContains(whitelist.geonetwork, GeomFromText(CONCAT('POINT(', t1.point, ' 0)'))))
where whitelist.id is null
;
This seems like a case where de-nomalizing t1 might be beneficial. Adding a GeomFrmTxt column with a value of GeomFromText(CONCAT('POINT(', t1.point, ' 0)')) could speed up the query you already have.
I have a table with the following format.
mysql> describe unit_characteristics;
+----------------------+------------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+----------------------+------------------+------+-----+---------+----------------+
| id | int(10) unsigned | NO | PRI | NULL | auto_increment |
| uut_id | int(10) unsigned | NO | PRI | NULL | |
| uut_sn | varchar(45) | NO | | NULL | |
| characteristic_name | varchar(80) | NO | PRI | NULL | |
| characteristic_value | text | NO | | NULL | |
| creation_time | datetime | NO | | NULL | |
| last_modified_time | datetime | NO | | NULL | |
+----------------------+------------------+------+-----+---------+----------------+
each uut_sn has multiple characteristic_name/value pairs. I want to use MySQL to generate a table
+----------------------+-------------+-------------+-------------+--------------+
| uut_sn | char_name_1 | char_name_2 | char_name_3 | char_name_4 | ... |
+----------------------+-------------+-------------+-------------+--------------+
| 00000 | char_val_1 | char_val_2 | char_val_3 | char_val_4 | ... |
| 00001 | char_val_1 | char_val_2 | char_val_3 | char_val_4 | ... |
| 00002 | char_val_1 | char_val_2 | char_val_3 | char_val_4 | ... |
| ..... | char_val_1 | char_val_2 | char_val_3 | char_val_4 | ... |
+----------------------+------------------+------+-----+---------+--------------+
Is this possible with just one query?
Thanks,
-peter
This is a standard pivot query:
SELECT uc.uut_sn,
MAX(CASE
WHEN uc.characteristic_name = 'char_name_1' THEN uc.characteristic_value
ELSE NULL
END) AS char_name_1,
MAX(CASE
WHEN uc.characteristic_name = 'char_name_2' THEN uc.characteristic_value
ELSE NULL
END) AS char_name_2,
MAX(CASE
WHEN uc.characteristic_name = 'char_name_3' THEN uc.characteristic_value
ELSE NULL
END) AS char_name_3,
FROM unit_characteristics uc
GROUP BY uc.uut_sn
To make it dynamic, you need to use MySQL's dynamic SQL syntax called Prepared Statements. It requires two queries - the first gets a list of the characteristic_name values, so you can concatenate the appropriate string into the CASE expressions like you see in my example as the ultimate query.
You're using the EAV antipattern. There's no way to automatically generate the pivot table you describe, without hardcoding the characteristics you want to include. As #OMG Ponies mentions, you need to use dynamic SQL to general the query in a custom fashion for the set of characteristics you want to include in the result.
Instead, I recommend you fetch the characteristics one per row, as they are stored in the database, and if you want an application object to represent a single UUT with all its characteristics, you write code to loop over the rows as you fetch them in your application, collecting them into objects.
For example in PHP:
$sql = "SELECT uut_sn, characteristic_name, characteristic_value
FROM unit_characteristics";
$stmt = $pdo->query($sql);
$objects = array();
while ($row = $stmt->fetch()) {
if (!isset($objects[ $row["uut_sn"] ])) {
$object[ $row["uut_sn"] ] = new Uut();
}
$objects[ $row["uut_sn"] ]->$row["characteristic_name"]
= $row["characterstic_value"];
}
This has a few advantages over the solution of hardcoding characteristic names in your query:
This solution takes only one SQL query instead of two.
No complex code is needed to build your dynamic SQL query.
If you forget one of the characteristics, this solution automatically finds it anyway.
GROUP BY in MySQL is often slow, and this avoids the GROUP BY.