Hello everyone I am having trouble and I can't seem to find an answer that will work for my problem.
I am using Microsoft Access and running a Select query. What I want to then do is change the values in a column for this query.
for example
SELECT Table.column1, Table.Column2
FROM Table
I get the following:
|Column1|Column2|
A 1
B 2
C 3
D 2
E 1
F 2
G 3
H 3
I 1
J 2
K 2
I want it so that the query now replaces all the 1s in column2 with 100, all the 2s in column2 with 200 and all the 3s in column2 with 300.
What I dont want to do is update the values in column2 in the original table, I want to change the values just in the query.
If your column2 data are only 1, 2 and 3 you can multiply by 100
SELECT Table.column1
, Table.Column2 * 100 as Column2
FROM Table
If your data contains other values than 1,2 and 3 you can use IIF
SELECT Table.column1
, IIF(Table.Column2 in (1,2,3),Table.Column2 * 100, Table.Column2) as Column2
FROM Table
You can do calculations in your select queries, e.g.:
SELECT Table.column1, Table.Column2 * 100 As Column2
FROM Table
This displays the value of Column2 multiplied by 100, but doesn't modify the underlying table.
You can't modify specific rows just in a query. If you want to modify specific rows, you can just copy the table, or use a make-table query to insert the results of a query in a table and then modify that table.
Other option with IIF() :
select Col1, iif ( Col2 = 1, 100,
iif ( Col2 = 2, 200,
iif ( Col2 = 3, 300, col2 )
)
) as col2
from table t;
Use the switch() function:
select column1,
switch(column2 = 1, 100,
column2 = 2, 200,
column2 = 3, 300,
column2
) as new_column2
from t;
Related
I'm trying to summarize data in a table:
counting total rows
counting values on specific fields
getting the distinct values on specific fields
and, more importantly, I'm struggling with:
getting the count for each field nested in an object
given this data
COL1
COL2
A
0
null
1
B
null
B
null
the expected result from this query would be:
with dummy as (
select 'A' as col1, 0 as col2
union all
select null, 1
union all
select 'B', null
union all
select 'B', null
)
select
count(1) as total
,count(col1) as col1
,array_agg(distinct col1) as dist_col1
--,object_construct(???) as col1_object_count
,count(col2) as col2
,array_agg(distinct col2) as dist_col2
--,object_construct(???) as col2_object_count
from
dummy
TOTAL
COL1
DIST_COL1
COL1_OBJECT_COUNT
COL2
DIST_COL2
COL2_OBJECT_COUNT
4
3
["A", "B"]
{"A": 1, "B", 2, null: 1}
2
[0, 1]
{0: 1, 1: 1, null: 2}
I've tried several functions inside OBJECT_CONSTRUCT mixed with ARRAY_AGG, but all failed
OBJECT_CONSTRUCT can work with several columns but only given all (*), if you try a select statement inside, it will fail
another issue is that analytical functions are not easily taken by the object or array functions in Snowflake.
You could use Snowflake Scripting or Snowpark for this but here's a solution that is somewhat flexible so you can apply it to different tables and column sets.
Create test table/view:
Create or Replace View dummy as (
select 'A' as col1, 0 as col2
union all
select null, 1
union all
select 'B', null
union all
select 'B', null
);
Set session variables for table and colnames.
set tbname = 'DUMMY';
set colnames = '["COL1", "COL2"]';
Create view that generates the required table_column_summary data:
Create or replace View table_column_summary as
with
-- Create table of required column names
cn as (
select VALUE::VARCHAR CNAME
from table(flatten(input => parse_json($colnames)))
)
-- Convert rows into objects
,ro as (
select
object_construct_keep_null(*) row_object
-- using identifier on session variable to dynamically supply table/view name
from identifier($tbname) )
-- Flatten row objects into key/values
,rof as (
select
key col_name,
ifnull(value,'null')::VARCHAR col_value
from ro, lateral flatten(input => row_object), cn
-- You will only need this filter if you need a subset
-- of columns from the source table/query summarised
where col_name = cn.cname)
-- Get the column value distinct value counts
,cdv as (
select col_name,
col_value,
sum(1) col_value_count
from rof
group by 1,2
)
-- and derive required column level stats and combine with cdv
,cv as (
select
(select count(1) from dummy) total,
col_name,
object_construct('COL_COUNT', count(col_value) ,
'COL_DIST', array_agg(distinct col_value),
'COL_OBJECT_COUNT', object_agg(col_value,col_value_count)) col_values
from cdv
group by 1,2)
-- Return result
Select * from cv;
Use this final query if you want a solution that works flexibility with any table/columns provided as input...
Select total, object_agg(col_name, col_values) col_values_obj
From table_column_summary
Group by 1;
Or use this final query if you want the fixed columns output as described in your question...
Select total,
COL1[0]:COL_COUNT COL1,
COL1[0]:COL_DIST DIST_COL1,
COL1[0]:COL_OBJECT_COUNT COL1_OBJECT_COUNT,
COL2[0]:COL_COUNT COL2,
COL2[0]:COL_DIST DIST_COL2,
COL2[0]:COL_OBJECT_COUNT COL2_OBJECT_COUNT
from table_column_summary
PIVOT ( ARRAY_AGG ( col_values )
FOR col_name IN ( 'COL1', 'COL2' ) ) as pt (total, col1, col2);
I have a row of data and I want to turn this row into a column so I can use a cursor to run through the data one by one. I have tried to use
SELECT * FROM TABLE(PIVOT(TEMPROW))
but I get
'PIVOT' Invalid Identifier error.
I have also tried that same syntax but with
('select * from TEMPROW')
Everything I see using pivot is always using count or sum but I just want this one single row of all varchar2 to turn into a column.
My row would look something like this:
ABC | 123 | aaa | bbb | 111 | 222 |
And I need it to turn into this:
ABC
123
aaa
bbb
111
222
My code is similar to this:
BEGIN
OPEN C_1 FOR SELECT * FROM TABLE(PIVOT( 'SELECT * FROM TEMPROW'));
LOOP
FETCH C_1 INTO TEMPDATA;
EXIT WHEN C_2%NOTFOUND;
DBMS_OUTPUT.PUT_LINE(1);
END LOOP;
CLOSE C_1;
END;
You have to unpivot to convert whole row into 1 single column
select * from Table
UNPIVOT
(col for col in (
'ABC' , '123' , 'aaa' ,' bbb' , '111' , '222'
))
or use union but for that you need to add col names manually like
Select * from ( Select col1 from table
union
select col2 from table union...
Select coln from table)
sample output to show as below
One option for unpivoting would be numbering columns by decode() and cross join with the query containing the column numbers :
select decode(myId, 1, col1,
2, col2,
3, col3,
4, col4,
5, col5,
6, col6 ) as result_col
from temprow
cross join (select level AS myId FROM dual CONNECT BY level <= 6 );
or use a query with unpivot keyword by considering the common expression for the column ( namely col in this case ) must have same datatype as corresponding expression :
select result_col from
(
select col1, to_char(col2) as col2, col3, col4,
to_char(col5) as col5, to_char(col6) as col6
from temprow
)
unpivot (result_col for col in (col1,col2,col3,col4,col5,col6));
Demo
I have an issue where in my data I will have a record returned where a column value will look like
-- query
Select col1 from myTable where id = 23
-- result of col1
111, 104, 34, 45
I want to feed these values to an in clause. So far I have tried:
-- Query 2 -- try 1
Select * from mytableTwo
where myfield in (
SELECT col1
from myTable where id = 23)
-- Query 2 -- try 2
Select * from mytableTwo
where myfield in (
SELECT '''' +
Replace(col1, ',', ''',''') + ''''
from myTable where id = 23)
-- query 2 test -- This works and will return data, so I verify here that data exists
Select * from mytableTwo
where myfield in ('111', '104', '34', '45')
Why aren't query 2 try 1 or 2 working?
You don't want an in clause. You want to use like:
select *
from myTableTwo t2
where exists (select 1
from myTable t
where id = 23 and
', '+t.col1+', ' like '%, '+t2.myfield+', %'
);
This uses like for the comparison in the list. It uses a subquery for the value. You could also phrase this as a join by doing:
select t2.*
from myTableTwo t2 join
myTable t
on t.id = 23 and
', '+t.col1+', ' like '%, '+t2.myfield+', %';
However, this could multiply the number of rows in the output if there is more than one row with id = 23 in myTable.
If you observe closely, Query 2 -- try 1 & Query 2 -- try 2 are considered as single value.
like this :
WHERE myfield in ('111, 104, 34, 45')
which is not same as :
WHERE myfield in ('111', '104', '34', '45')
So, If you intend to filter myTable rows from MyTableTwo, you need to extract the values of fields column data to a table variable/table valued function and filter the data.
I have created a table valued function which takes comma seperated string and returns a table value.
you can refer here T-SQL : Comma separated values to table
Final code to filter the data :
DECLARE #filteredIds VARCHAR(100)
-- Get the filter data
SELECT #filteredIds = col1
FROM myTable WHERE id = 23
-- TODO : Get the script for [dbo].[GetDelimitedStringToTable]
-- from the given link and execute before this
SELECT *
FROM mytableTwo T
CROSS APPLY [dbo].[GetDelimitedStringToTable] ( #filteredIds, ',') F
WHERE T.myfield = F.Value
Please let me know If this helps you!
I suppose col is a character type, whose result would be like like '111, 104, 34, 45'. If this is your situation, it's not the best of the world (denormalized database), but you can still relate these tables by using character operators like LIKE or CHARINDEX. The only gotcha is to convert the numeric column to character -- the default conversion between character and numeric is numeric and it will cause a conversion error.
Since #Gordon, responded using LIKE, I present a solution using CHARINDEX:
SELECT *
FROM mytableTwo tb2
WHERE EXISTS (
SELECT 'x'
FROM myTable tb1
WHERE tb1.id = 23
AND CHARINDEX(CONVERT(VARCHAR(20), tb2.myfield), tb1.col1) > 0
)
I have this table:
Vals
Val1 Val2 Score
A B 1
C 2
D 3
I would like the output to be a single column that is the "superset" of the Vals1 and Val2 variable. It also keeps the "score" variable associated with that value.
The output should be:
Val Score
A 1
B 1
C 2
D 3
Selecting from this table twice and then unioning is absolutely not a possibility because producing it is very expensive. In addition I cannot use a with clause because this query uses one in a sub-query and for some reason Oracle doesn't support two with clauses.
I don't really care about how repeat values are dealt with, whatever is easiest/fastest.
How can I generate my appropriate output?
Here is solution without using unpivot.
with columns as (
select level as colNum from dual connect by level <= 2
),
results as (
select case colNum
when 1 then Val1
when 2 then Val2
end Val,
score
from vals,
columns
)
select * from results where val is not null
Here is essentially the same query without the WITH clause:
select case colNum
when 1 then Val1
when 2 then Val2
end Val,
score
from vals,
(select level as colNum from dual connect by level <= 2) columns
where case colNum
when 1 then Val1
when 2 then Val2
end is not null
Or a bit more concisely
select *
from ( select case colNum
when 1 then Val1
when 2 then Val2
end Val,
score
from vals,
(select level as colNum from dual connect by level <= 2) columns
) results
where val is not null
try this, looks like you want to convert column values into rows
select val1, score from vals where val1 is not null
union
select val2,score from vals where val2 is not null
If you're on Oracle 11, unPivot will help:
SELECT *
FROM vals
UNPIVOT ( val FOR origin IN (val1, val2) )
you can choose any names instead of 'val' and 'origin'.
See Oracle article on pivot / unPivot.
I want to build columns that calculated with each other. (Excuse my English)
Example:
Id Column1 Column2 Column3
1 5 5 => Same as Column1 5 => Same as Column2
2 2 12 => column1 current + column2.prev + column3.previous = 2+5+5 17 => column2.current + column3.prev = 12+5
3 3 32 => 3+12+17 49 => 32+17
easier way to see:
Id Column1 Column2 Column3
1 5 5 => Same as Column1 5 => Same as Column2
2 2 12 => 2+5+5 17 => 12+5
3 3 32 => 3+12+17 49 => 32+17
so complicated??? :-(
The previous issue was calculating Column3 with the new calculated column as Column2. But now, it must be renew with the just calculated Column2 and the previous record of Column3 as well. If you want to have a look at the previous post, here it is.
Here is my previous recursive CTE code. It works like, 1st, calculate column2 with previous record of current column (c.Column2) in cteCalculation, and then calculate new column3 in cte2 with just calculated column2 from cteCalculation.
/copied from that previous post/
;with cteCalculation as (
select t.Id, t.Column1, t.Column1 as Column2
from table_1 t
where t.Id = 1
union all
select t.Id, t.Column1, (t.Column1 + c.Column2) as Column2
from table_1 t
inner join cteCalculation c
on t.Id-1 = c.id
),
cte2 as(
select t.Id, t.Column1 as Column3
from table_1 t
where t.Id = 1
union all
select t.Id, (select column2+1 from cteCalculation c where c.id = t.id) as Column3
from table_1 t
inner join cte2 c2
on t.Id-1 = c2.id
)
select c.Id, c.Column1, c.Column2, c2.column3
from cteCalculation c
inner join cte2 c2 on c.id = c2. id
Now I wanna extend it like calculate 2 columns with the data from each other. Means, use 2nd to calc the 3rd, and use 3rd to get new 2nd column data. Hope you can get it.
This is an example how to achive this using recursive CTE
create table #tmp (id int identity (1,1), Column1 int)
insert into #tmp values(5)
insert into #tmp values(2)
insert into #tmp values(3);
with counter as
(
SELECT top 1 id, Column1, Column1 as Column2, Column1 as Column3 from #tmp
UNION ALL
SELECT t.id, t.Column1,
t.Column1 + counter.Column2 + counter.Column3,
(t.Column1 + counter.Column2 + counter.Column3) + counter.Column3 FROM counter
INNER JOIN #tmp t ON t.id = counter.id + 1
)
select * from counter
You'll need to use a Recursive CTE since the values of subsequent columns are dependent upon earlier results.
Do this in pieces, too. Have your first query just return the correct values for Column1. Your next (recursive CTE) query will add the results for Column2, and so on.
OK I'm assuming you're doing inserts into column 1 here of various values.
Essentially col2 always = new col1 value + old col2 value + old col 3 value
col3 = new col2 value + old col3 value
so col3 = (new col1 value + old col2 value + old col 3 value) + old col3 value
So an INSTEAD OF Insert trigger is probably the easiest way to implement.
CREATE TRIGGER tr_xxxxx ON Tablename
INSTEAD OF INSERT
AS
INSERT INTO Tablename (Column1, Column2, Column3)
SELECT ins.col1, ins.col1+t.col2+t.col3, ins.col1+t.col2+t.col3+t.col3
FROM Tablename t INNER JOIN Inserted ins on t.Id = ins.Id
The trigger has access to both the existing (old) values in Tablename t, and the new value being inserted (Inserted.col1).