Suppose I have the following table:
|---------------------|
| id |
|---------------------|
| 12 |
|---------------------|
| 390 |
|---------------------|
| 13 |
|---------------------|
And I want to create another column based on a map of the id column, for example:
12 -> qwert
13 -> asd
390 -> iop
So I basically want a query to create a column based on that map, my final table would be:
|---------------------|---------------------|
| id | col |
|---------------------|---------------------|
| 12 | qwert |
|---------------------|---------------------|
| 390 | iop |
|---------------------|---------------------|
| 13 | asd |
|---------------------|---------------------|
I have this map in a python dictionary.
Is this possible?
(It is basically pandas.map)
It appears that you wish to "fix" some data that is already in your PostgreSQL database.
You could include the data using this technique:
WITH foo AS (VALUES (12, 'qwert'), (13, 'asd'), (390, 'iop'))
SELECT table.id, foo.column2
FROM table
JOIN foo ON (foo.column1 = table.id)
You could do it as an UPDATE statement, but it gets tricky. It would probably be easier to craft a SELECT statement that has everything you want, then use CREATE TABLE new_table AS SELECT...
See: CREATE TABLE AS - Amazon Redshift
Related
I have a table "table1" like this:
+------+--------------------+
| id | barcode | lot |
+------+-------------+------+
| 0 | ABC-123-456 | |
| 1 | ABC-123-654 | |
| 2 | ABC-789-EFG | |
| 3 | ABC-456-EFG | |
+------+-------------+------+
I have to extract the number in the center of the column "barcode", like with this request :
SELECT SUBSTR(barcode, 5, 3) AS ToExtract FROM table1;
The result:
+-----------+
| ToExtract |
+-----------+
| 123 |
| 123 |
| 789 |
| 456 |
+-----------+
And insert this into the column "lot" .
follow along the lines
UPDATE table_name
SET column1 = value1, column2 = value2, ...
WHERE condition;
i.e in your case
UPDATE table_name
SET lot = SUBSTR(barcode, 5, 3)
WHERE condition;(if any)
UPDATE table1 SET Lot = SUBSTR(barcode, 5, 3)
-- WHERE ...;
Many databases support generated (aka "virtual"/"computed" columns). This allows you to define a column as an expression. The syntax is something like this:
alter table table1 add column lot varchar(3) generated always as (SUBSTR(barcode, 5, 3))
Using a generated column has several advantages:
It is always up-to-date.
It generally does not occupy any space.
There is no overhead when creating the table (although there is overhead when querying the table).
I should note that the syntax varies a bit among databases. Some don't require the type specification. Some use just as instead of generated always as.
CREATE TABLE Table1(id INT,barcode varchar(255),lot varchar(255))
INSERT INTO Table1 VALUES (0,'ABC-123-456',NULL),(1,'ABC-123-654',NULL),(2,'ABC-789-EFG',NULL)
,(3,'ABC-456-EFG',NULL)
UPDATE a
SET a.lot = SUBSTRING(b.barcode, 5, 3)
FROM Table1 a
INNER JOIN Table1 b ON a.id=b.id
WHERE a.lot IS NULL
id | barcode | lot
-: | :---------- | :--
0 | ABC-123-456 | 123
1 | ABC-123-654 | 123
2 | ABC-789-EFG | 789
3 | ABC-456-EFG | 456
db<>fiddle here
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
Fellow SOers,
Currently I am stuck with the following Problem.
Say we have table "data" and table "factor"
"data":
---------------------
| col1 | col2 |
----------------------
| foo | 2 |
| bar | 3 |
----------------------
and table "factor" (the amount of rows is variable)
---------------------
| name | val |
---------------------
| f1 | 7 |
| f2 | 8 |
| f3 | 9 |
| ... | ... |
---------------------
and the following result should look like this:
---------------------------------
| col1 | f1 | f2 | f3 | ...|
---------------------------------
| foo | 14 | 16 | 18 | ...|
| bar | 21 | 24 | 27 | ...|
---------------------------------
So basically I want the column "col2" multiplicated with all the contents of "val" of table "factor" AND the content of column "name" should act as tableheader/columnname for the result.
We are using postgres 9.3 (upgrade to higher version may be possible), so an extended Search resulted in multiple possible solutions: using crosstab (though even with crosstab I was not able to figure this one out), using CTE "With" (preferred, but also no luck). Probably this may also be done with the correct use of array() and unnest().
Hence, any help is appreciated on how to achieve this (the less code, the better)
Tnx in advance!
This package seems to do what you want:
https://github.com/hnsl/colpivot
I'm working on an old SQL Server database that has several tables that look like the following:
|-------------|-----------|-------|------------|------------|-----|
| MachineName | AlarmName | Event | AlarmValue | SampleTime | ... |
|-------------|-----------|-------|------------|------------|-----|
| 3 | 180 | 8 | 6.780 | 2014-02-24 | |
| 9 | 67 | 8 | 1.45 | 2014-02-25 | |
| ... | | | | | |
|-------------|-----------|-------|------------|------------|-----|
There is a separate table in the database that only contains unique strings, as well as the index for each unique string. The unique string table looks like this:
|----------|--------------------------------|
| Id | String |
|----------|--------------------------------|
| 3 | MyMachine |
| ... | |
| 8 | High CPU Usage |
| ... | |
| 67 | 404 Error |
| ... | |
|----------|--------------------------------|
Thus, when we want to get something out of the database, we get the respective rows out, then lookup each missing string based on the index value.
What I'm hoping to do is to replace all of the string indexes with the actual values in a single query without having to do post-processing on the query result.
However, I can't figure out how to do this in a single query. Do I need to use multiple JOINs? I've only been able to figure out how to replace a single value by doing something like -
SELECT UniqueString.String AS "MachineName" FROM UniqueString
JOIN Alarm ON Alarm.MachineName = UniqueString.Id
Any help would be much appreciated!
Yes, you can do multiple joins to the UniqueStrings table, but change the order to start with the table you are reporting on and use unique aliases for the joined table. Something like:
SELECT MN.String AS 'MachineName', AN.String as 'AlarmName' FROM Alarm A
JOIN UniqueString MN ON A.MachineName = MN.Id
JOIN UniqueString AN ON A.AlarmName = AN.Id
etc for any other columns
I have list of names and I need to insert into a table with a primary key which is auto generated and another three columns which will have the same data for each name. Is there any way to acheive this in single query?
| ID | Name | Age| Class|In-Charge|
|121 | Luc | 12 | Five | 47855 |
|122 | Wayne| 12 | Five | 47855 |
|123 | Lih | 12 | Five | 47855 |
You can use something like this where you SELECT the name from your list and the other values are just static values:
insert into yourtable (Name, Age, Class, [In-Charge])
select Name, 12, 'Five', 47855
from yourlist
See SQL Fiddle with Demo