This question already has answers here:
Does update change the order of records in a table in PostgreSQL?
(3 answers)
Why postgres returns unordered data in select query, after updation of row?
(2 answers)
Postgresql: row number changes on update
(1 answer)
Closed last year.
My app has a table definition as follows to manage users:
Column | Type | Collation | Nullable | Default
-----------+---------+-----------+----------+----------------------------------
id | integer | | not null | generated by default as identity
utoken | integer | | not null |
username | text | | not null |
password | text | | not null |
email | text | | |
tos | integer | | not null | 0
suspended | integer | | not null | 0
visible | integer | | not null | 1
flags | text | | |
My test table has 3 records. I did an update to records 1 and 2 by:
UPDATE table
SET flags = (SELECT flags FROM table WHERE id = 3)
WHERE id IN (1,2)
After the update, the records based on id, were re-ordered to 3,1,2 for some reason.
Is this a result of the update or something related to the table design following the update?
Related
I want to get data in a single row from two tables which have one to many relation.
Primary table
Secondary table
I know that for each record of primary table secondary table can have maximum 10 rows. Here is structure of the table
Primary Table
-------------------------------------------------
| ImportRecordId | Summary |
--------------------------------------------------
| 1 | Imported Successfully |
| 2 | Failed |
| 3 | Imported Successfully |
-------------------------------------------------
Secondary table
------------------------------------------------------
| ImportRecordId | CodeName | CodeValue |
-------------------------------------------------------
| 1 | ABC | 123456A |
| 1 | DEF | 8766339 |
| 1 | GHI | 887790H |
------------------------------------------------------
I want to write a query with inner join to get data from both table in a way that from secondary table each row should be treated as column instead showing as multiple row.
I can hard code 20 columns names(as maximum 10 records can exist in secondary table and i want to display values of two columns in a single row) so if there are less than 10 records in the secondary table all other columns will be show as null.
Here is expected Output. You can see that for first record in primary table there was only three rows that's why two required columns from these three rows are converted into columns and for all others columns values are null.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| ImportRecordId | Summary | CodeName1 | CodeValue1 | CodeName2 | CodeValue2 | CodeName3 | CodeValue3 | CodeName4 | CodeValue4| CodeName5 | CodeValue5| CodeName6 | CodeValue6| CodeName7 | CodeValue7 | CodeName8 | CodeValue8 | CodeName9 | CodeValue9 | CodeName10 | CodeValue10|
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| 1 | Imported Successfully | ABC | 123456A | DEF | 8766339 | GHI | 887790H | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL |
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Here is my simple SQL query which return all data from both tables but instead multiple rows from secondary table i want to get them in a single row like above result set.
Select p.ImportRecordId,p.Summary,s.*
from [dbo].[primary_table] p
inner join [dbo].[secondary_table] s on p.ImportRecordId = s.ImportRecordId
The following uses Row_Number(), a JOIN and a CROSS APPLY to create the source of the PIVOT
You'll have to add the CodeName/Value 4...10
Example
Select *
From (
Select A.[ImportRecordId]
,B.Summary
,C.*
From (
Select *
,RN = Row_Number() over (Partition by [ImportRecordId] Order by [CodeName])
From Secondary A
) A
Join Primary B on A.[ImportRecordId]=B.[ImportRecordId]
Cross Apply (values (concat('CodeName' ,RN),CodeName)
,(concat('CodeValue',RN),CodeValue)
) C(Item,Value)
) src
Pivot (max(value) for Item in (CodeName1,CodeValue1,CodeName2,CodeValue2,CodeName3,CodeValue3) ) pvt
Returns
ImportRecordId Summary CodeName1 CodeValue1 CodeName2 CodeValue2 CodeName3 CodeValue3
1 Imported Successfully ABC 123456A DEF 8766339 GHI 887790H
I have a following table in Postgres
+----+-----------+----------------------+---------+
| id | user_fk| language_fk | details |
+----+-----------+----------------------+---------+
| 1 | 2 | en-us | 123 |
| 2 | 3 | en-us | 456 |
| 3 | 4 | en-us | 789 |
| 4 | 4 | es-la | 012 |
+----+-----------+----------------------+---------+
And I want to reduce this to the following SQL statement:
UPDATE users SET details = '{"en-us": "789", "es-la": "012"}' WHERE id = 4;
UPDATE users SET details = '{"en-us": "123"}' WHERE id = 2;
UPDATE users SET details = '{"en-us": "456"}' WHERE id = 3;
So I want to reduce languages per user and put it in a different table. Is there a way to do this in Postgres?
Use the function jsonb_object_agg() to get the expected output:
select
min(id) as id,
user_fk,
jsonb_object_agg(language_fk, details) as details
from users
group by user_fk
id | user_fk | details
----+---------+----------------------------------
1 | 2 | {"en-us": "123"}
2 | 3 | {"en-us": "456"}
3 | 4 | {"en-us": "789", "es-la": "012"}
(3 rows)
You cannot update the table in this way because of different types of old and new details column. Create a new table with reduced columns using create table from select:
create table new_users as
select
min(id) as id,
user_fk,
jsonb_object_agg(language_fk, details) as details
from users
group by user_fk;
I have a dataset which looks like so
ID | PName | Node | Val |
1 | Tag | Name | XBA |
2 | Tag | Desc | Dec1 |
3 | Tag | unit | Int |
6 | Tag | tids | 100 |
7 | Tag | post | AAA |
1 | Tag | Name | XBB |
2 | Tag | Desc | Des9 |
3 | Tag | unit | Float |
7 | Tag | post | BBB |
6 | Tag | tids | 150 |
I would like the result in my report to be
Name | Desc | Unit | Tids | Post |
XBA | Dec1 | int | 100 | AAA |
XBB | Des9 | Float | 150 | BBB |
I have tried using a SSRS Matrix with
Row: PName
Data: Node
Value: Val
The results were simply one row with Name and next row with desc and next with unit etc. Its not all in the same rows and also the second row was missing. This is possibly because there is no grouping on the dataset.
What is a good way of achieving the expected results?
I would not recommend this for a production scenario but if you need to knock out a report quickly or something you can try this. I would just not feel comfortable that the order of the records you get will always be what you expect.
You COULD try to insert the results of the SP into a table (regular table, temp table, table variable...doesn't matter really as long as you can get an identity column added). Assuming that the rows always come out in the correct order (which is probably not a valid assumption 100% of the time) then add an identity column on the table to get a unique row number for each row. From there you should be able to write some math logic to "group" your values together and then pivot out what you want.
create table #temp (ID int, PName varchar(100), Node varhar(100), Val varchar(100))
insert #temp exec (your stored proc)
alter table #temp add UniqueID int identity
then use UniqueID (modulo on 5 perhaps?) to group records together and then pivot
I have created a HIVE partition table and when I run describe table I see other table properties as well as the table column details. If I want to see only the table column details, then what command can I use?
create table t1 (x int, y int, s string) partitioned by (z date) stored as sequencefile;
describe t1;
+--------------------------+-----------------------+-----------------------+--+
| col_name | data_type | comment |
+--------------------------+-----------------------+-----------------------+--+
| x | int | |
| y | int | |
| s | string | |
| z | date | |
| | NULL | NULL |
| # Partition Information | NULL | NULL |
| # col_name | data_type | comment |
| | NULL | NULL |
| z | date | |
+--------------------------+-----------------------+-----------------------+--+
Can the last 5 rows be avoided?
| NULL | NULL |
| # Partition Information | NULL | NULL |
| # col_name | data_type | comment |
| | NULL | NULL |
| z | date | |
Also what does this NULL | NULL row means?
What you're looking for is this configuration parameter:
set hive.display.partition.cols.separately=false
From hive documentation:
In Hive 0.10.0 and earlier, no distinction is made between partition columns and non-partition columns while displaying columns for DESCRIBE TABLE. From Hive 0.12.0 onwards, they are displayed separately.
In Hive 0.13.0 and later, the configuration parameter hive.display.partition.cols.separately lets you use the old behavior, if desired (HIVE-6689). For an example, see the test case in the patch for HIVE-6689.
This question already has answers here:
Simple CHECK Constraint not so simple
(2 answers)
Closed 8 years ago.
I have a table with three columns, the ID of the relation, the ID of the object related and the value of the object. The table may have as many repeated ID-Value relations except when the Value is 0 for the same ID.
Correct Incorrect
+--------+--------+-------+ +--------+--------+-------+
| PK_ID | ID | Value | | PK_ID | ID | Value |
+--------+--------+-------+ +--------+--------+-------+
| 1 | 1 | 1 | | 1 | 1 | 1 |
| 2 | 1 | 1 | | 2 | 1 | 1 |
| 3 | 2 | 0 | | 3 | 2 | 0 |
+--------+--------+-------+ | 4 | 2 | 0 |
+--------+--------+-------+
The question is how can I enforce it not to allow a repeated ID-Value relation when the value is 0?
As pointed out by #Martin Smith in the comments of the question this is indeed similar to Simple CHECK Constraint not so simple and in the answer to that question (although it was for sql-08) there's an example solution for sql-00 and 05.
The idea is to create an index view to simulate a filtered unique index with the following code:
CREATE VIEW dbo.myTableView
WITH SCHEMABINDING
AS
SELECT ID
FROM dbo.myTable
WHERE Value = 0
GO
CREATE UNIQUE CLUSTERED INDEX ix ON dbo.myTableView(ID)