I want to transpose the rows to columns using Pivot function in Oracle and/or SQL Server using Pivot function. My use case is very similar to this Efficiently convert rows to columns in sql server
However, I am organizing data by specific data type (below StringValue and NumericValue is shown).
This is my example:
----------------------------------------------------------------------
| Id | Person_ID | ColumnName | StringValue | NumericValue |
----------------------------------------------------------------------
| 1 | 1 | FirstName | John | (null) |
| 2 | 1 | Amount | (null) | 100 |
| 3 | 1 | PostalCode | (null) | 112334 |
| 4 | 1 | LastName | Smith | (null) |
| 5 | 1 | AccountNumber | (null) | 123456 |
----------------------------------------------------------------------
This is my result:
---------------------------------------------------------------------
| FirstName |Amount| PostalCode | LastName | AccountNumber |
---------------------------------------------------------------------
| John | 100 | 112334 | Smith | 123456 |
---------------------------------------------------------------------
How can I build the SQL Query?
I have already tried using MAX(DECODE()) and CASE statement in Oracle. However the performance is very poor. Looking to see if Pivot function in Oracle and/or SQL server can do this faster. Or should I go to single column value?
Below code will satisfy your requirement
Create table #test
(id int,
person_id int,
ColumnName varchar(50),
StringValue varchar(50),
numericValue varchar(50)
)
insert into #test values (1,1,'FirstName','John',null)
insert into #test values (2,1,'Amount',null,'100')
insert into #test values (3,1,'PostalCode',null,'112334')
insert into #test values (4,1,'LastName','Smith',null)
insert into #test values (5,1,'AccountNumber',null,'123456')
--select * from #test
Declare #Para varchar(max)='',
#Para1 varchar(max)='',
#main varchar(max)=''
select #Para += ','+QUOTENAME(ColumnName)
from (select distinct ColumnName from #test) as P
set #Para1= stuff(#para ,1,1,'')
print #Para1
set #main ='select * from (
select coalesce(StringValue,numericValue) as Val,ColumnName from #test) as Main
pivot
(
min(val) for ColumnName in ('+#Para1+')
) as pvt'
Exec(#main)
Related
I have a table populated by CSV raw data
| NNAME | DateDriven | username |
|--------------------------------|
| Thunder| 1-1-1999 | mickey |
|--------------------------------|
And an existing MSSQL database
> Tables
Drivers
| ------------- |
| ID | username |
|---------------|
| 1 | mickey |
| 2 | jonny |
| 3 | ryan |
-----------------
Cars
-----------------------------
| ID | NNAME | DateDriven |
|---------------------------|
| | | |
-----------------------------
Car_Drivers Table
-----------------------
| Cars_ID | Driver_ID |
|---------------------|
| | |
-----------------------
How can I take the cvs table data and insert it into the above? I am very lost!
CARS IDs are identity(1,1). Table Car_Drivers has a composite primary key off two foreign keys.
What I think I need to do is create a join to convert username to ID but I am getting lost completing the insert query.
Desired outcome
Cars Table
-----------------------------
| ID | NNAME | DateDriven |
|---------------------------|
| 1 | Thunder | 1-1-1999 |
-----------------------------
Car_Drivers Table
-----------------------
| Cars_ID | Driver_ID |
|---------------------|
| 1 | 1 |
-----------------------
The following ought to do what you need. The problem is that you need to keep some temporary data around as rows are inserted into Cars, but some of the data is from a different table. Merge provides the answer:
-- Create the test data.
declare #CSVData as Table ( NName NVarChar(16), DateDriven Char(8), Username NVarChar(16));
insert into #CSVData ( NName, DateDriven, Username ) values
( N'Thunder', '1-1-1999', N'mickey' );
select * from #CSVData;
declare #Drivers as Table ( Id SmallInt Identity, Username NVarChar(16) );
insert into #Drivers ( Username ) values
( N'mickey' ), ( N'jonny' ), ( N'ryan' );
select * from #Drivers;
declare #Cars as Table ( Id SmallInt Identity, NName NVarChar(16), DateDriven Char(8) );
declare #CarDrivers as Table ( Cars_Id SmallInt, Driver_Id SmallInt );
-- Temporary data needed for the #CarDrivers table.
declare #NewCars as Table ( Username NVarChar(16), Cars_Id SmallInt );
-- Merge the new data into #Cars .
-- MERGE allows the use of OUTPUT with references to columns not inserted,
-- e.g. Username .
merge into #Cars
using ( select NName, DateDriven, Username from #CSVData ) as CSVData
on 1 = 0
when not matched by target then
insert ( NName, DateDriven ) values ( CSVData.NName, CSVData.DateDriven )
output CSVData.Username, Inserted.Id into #NewCars;
-- Display the results.
select * from #Cars;
-- Display the temporary data.
select * from #NewCars;
-- Add the connections.
insert into #CarDrivers ( Cars_Id, Driver_Id )
select NewCars.Cars_Id, Drivers.Id
from #NewCars as NewCars inner join
#Drivers as Drivers on Drivers.Username = NewCars.Username;
-- Display the results.
select * from #CarDrivers;
DBFiddle.
I'm trying to count the number of consecutive days in two tables with the following structure:
| id | email | timestamp |
| -------- | -------------- | -------------- |
| 1 | hello#example.com | 2021-10-22 00:35:22 |
| 2 | hello2#example.com | 2021-10-21 21:17:41 |
| 1 | hello#example.com | 2021-10-19 00:35:22 |
| 1 | hello#example.com | 2021-10-18 00:35:22 |
| 1 | hello#example.com | 2021-10-17 00:35:22 |
I would like to count the number of consecutive days of activity. The data above would show:
| id | email | length |
| -------- | -------------- | -- |
| 1 | hello#example.com | 1 |
| 2 | hello2#example.com | 1 |
| 1 | hello#example.com | 3 |
This is made more difficult because I need to join the two tables using a UNION (or something similar and then run the grouping. I tried to build on this query (Finding the length of a series in postgres) but I'm unable to group by consecutive days.
select max(id) as max_id, email, count(*) as length
from (
select *, row_number() over wa - row_number() over wp as grp
from began_playing_video
window
wp as (partition by email order by id desc),
wa as (order by id desc)
) s
group by email, grp
order by 1 desc
Any ideas on how I could do this in Postgres?
First create an aggregate function in order to count the adjacent dates within an ascendant ordered list. The jsonb data type is used because it allows to mix various data types inside the same array :
CREATE OR REPLACE FUNCTION count_date(x jsonb, y jsonb, d date)
RETURNS jsonb LANGUAGE sql AS
$$
SELECT CASE
WHEN d IS NULL
THEN COALESCE(x,y)
ELSE
to_jsonb(d :: text)
|| CASE
WHEN COALESCE(x,y) = '[]' :: jsonb
THEN '[1]' :: jsonb
WHEN COALESCE(x->>0, y->>0) :: date + 1 = d :: date
THEN jsonb_set(COALESCE(x-0, y-0), '{-1}', to_jsonb(COALESCE(x->>-1, y->>-1) :: integer + 1))
ELSE COALESCE(x-0, y-0) || to_jsonb(1)
END
END ;
$$
DROP AGGREGATE IF EXISTS count_date(jsonb, date) ;
CREATE AGGREGATE count_date(jsonb, date)
(
sfunc = count_date
, stype = jsonb
) ;
Then iterate on the count_date on your table grouped by id :
WITH list AS (
SELECT id, email, count_date('[]', timestamp ORDER BY timestamp :: timestamp) as count_list
FROM your_table
GROUP BY id, email
)
SELECT id, email, jsonb_array_elements(count_list-0) AS length
FROM list
I have a couple of tables in Postgres database. I have joined and merges the tables. However, I would like to have common values in a specific column to appear together in the final table (In the end, I would like to perform groupby and maximum value calculation on the table).
The schema of the test tables looks like this:
Schema (PostgreSQL v11)
CREATE TABLE table1 (
id CHARACTER VARYING NOT NULL,
seq CHARACTER VARYING NOT NULL
);
INSERT INTO table1 (id, seq) VALUES
('UA502', 'abcdef'), ('UA503', 'ghijk'),('UA504', 'lmnop')
;
CREATE TABLE table2 (
id CHARACTER VARYING NOT NULL,
score FLOAT
);
INSERT INTO table2 (id, score) VALUES
('UA502', 2.2), ('UA503', 2.6),('UA504', 2.8)
;
CREATE TABLE table3 (
id CHARACTER VARYING NOT NULL,
seq CHARACTER VARYING NOT NULL
);
INSERT INTO table3 (id, seq) VALUES
('UA502', 'qrst'), ('UA503', 'uvwx'),('UA504', 'yzab')
;
CREATE TABLE table4 (
id CHARACTER VARYING NOT NULL,
score FLOAT
);
INSERT INTO table4 (id, score) VALUES
('UA502', 8.2), ('UA503', 8.6),('UA504', 8.8);
;
I performed join and union and oepration of the tables to get the desired columns.
Query #1
SELECT table1.id, table1.seq, table2.score
FROM table1 INNER JOIN table2 ON table1.id = table2.id
UNION
SELECT table3.id, table3.seq, table4.score
FROM table3 INNER JOIN table4 ON table3.id = table4.id
;
The output looks like this:
| id | seq | score |
| ----- | ------ | ----- |
| UA502 | qrst | 8.2 |
| UA502 | abcdef | 2.2 |
| UA504 | yzab | 8.8 |
| UA503 | uvwx | 8.6 |
| UA504 | lmnop | 2.8 |
| UA503 | ghijk | 2.6 |
However, the desired output should be:
| id | seq | score |
| ----- | ------ | ----- |
| UA502 | qrst | 8.2 |
| UA502 | abcdef | 2.2 |
| UA504 | yzab | 8.8 |
| UA504 | lmnop | 2.8 |
| UA503 | uvwx | 8.6 |
| UA503 | ghijk | 2.6 |
View on DB Fiddle
How should I modify my query to get the desired output?
I have a table 'employee' with two columns 'firstname' and 'lastname' and it has unique constraint on 'lastname' column.
If I am sending more than one row, how can I update matched rows from input and create new rows for unmatched.
Existing data in database:
|id | firstname | lastname |
+----+-------------+-----------+
| 1 | John | Doe |
Input rows:
| firstname | lastname |
+-----------+-----------+
| John1 | Doe |
| Bar | foo |
Here is the script I am using:
INSERT INTO Identification (firstname,lastname)
(VALUES
('John1','Doe'),
('Bar','foo')) as u2
ON CONFLICT ON CONSTRAINT lname_unique_constraint
DO UPDATE
SET
firstname = u2.firstname
RETURNING Id;
It gives me this error:
ERROR: syntax error at or near "as"
If the script works fine, it should leave database in the below state:
|id | firstname | lastname |
+----+-------------+-----------+
| 1 | John1 | Doe |
| 2 | Bar | foo |
NOTE:
I am using PostgreSQL 10.6 and id column is of type number and set to auto sequence.
You could use EXCLUDED:
INSERT
Note that the special excluded table is used to reference values originally proposed for insertion
INSERT INTO Identification (firstname,lastname)
VALUES
('John1','Doe'),
('Bar','foo')
ON CONFLICT ON CONSTRAINT fname_unique_constraint
DO UPDATE
SET
firstname = EXCLUDED.firstname
RETURNING Id;
db<>fiddle demo
psql (9.6.1, server 9.5.5)
employees
Column | Type | Modifiers | Storage | Stats target | Description
----------------+-----------------------------+-----------------------------------------------------------------+----------+--------------+---- ---------
employee_id | integer | not null default nextval('employees_employee_id_seq'::regclass) | plain | |
first_name | character varying(20) | | extended | |
last_name | character varying(25) | not null | extended | |
email | character varying(25) | not null | extended | |
phone_number | character varying(20) | | extended | |
hire_date | timestamp without time zone | not null | plain | |
job_id | character varying(10) | not null | extended | |
salary | numeric(8,2) | | main | |
commission_pct | numeric(2,2) | | main | |
manager_id | integer | | plain | |
department_id | integer
I need to extract employee number, last name, salary, salary increased by 15.5 % (expressed as a whole number), and the difference between the new and old salary.
I have done like this:
select employee_id,
last_name,
salary,
round(salary * 1.155, 0) as "New Salary",
round(salary * 1.155, 0) - salary as "Increase"
from employees;
What troubles me is that I have calculated the new salary twice.
I tried to use alias in the same select. Experimented like this:
select 2 as val_a, val_a - 4; --not working
Well, my solution outputs acceptable result. But isn't there a better solution?
That calculation is really nothing if you are worried about performance. Some optimizers may even reuse the calculations internally.
If you must do it yourself, you can use subquery like this:
select t.*,
New_Salary - salary as Increase
from (
select employee_id,
last_name,
salary,
round(salary * 1.155, 0) as New_Salary,
from employees
) t;
You can write it with a subquery, if you are "picky" about not computing twice the same values:
SELECT
*, "New Salary" - salary as "Increase"
FROM
(
SELECT
employee_id,
last_name,
salary,
round(salary * 1.155, 0) as "New Salary"
FROM
employees
) AS s0 ;
In practice, the difference when you run it a few times is neglectable:
dbfiddle here