I have a table INFO with 3 columns as NAME, ID and FLAG. The condition for select statement is if NAME column is not null it should display the NAME based on the ID and FLAG values from WHERE clause.
My original query was as follows,
Select NAME from INFO where ID=101 and FLAG='Y'
This query returns the NAME if it is present for given ID and FLAG condition. But shows NULL if NAME is not present for the given ID and FLAG condition (As it should as per the T-SQL properties)
In my case I want to execute the query only if NAME column value if NOT NULL.
Till now I have used CASE condition but it does not skips the execution
select CASE NAME is not null then NAME
else 'NA' end from INFO where ID=101 and FLAG='Y'
This only replace the resultant NULL with NA, Is there a way I can execute this select only if NAME column has values
Why not add an
and name is not null
to the where clause?
Related
I would like to use a SQL select statement that has the condition 'where column A is NULL change column B values to be equal to column C values'. How would I be able to incorporate this logic into a SELECT statement (Not an UPDATE statement as I cant change the tables on the server but want to query them from the server).
SELECT final.*
FROM final
The actual table is in the image below, here I want to change column Old to match column DirectUse if the Change column is null.
Try Case statement:
SELECT
Name, NameSimple, DirectUse, Year, Month,
CASE WHEN Change IS NULL THEN DirectUse ELSE Old END AS Old,
CurrentCons, Change
FROM final;
CASE: https://www.w3schools.com/sql/sql_case.asp
Can also be incorporated by UNION ALL:
SELECT Old
FROM final where Change is not null
UNION ALL
SELECT DirectUse
FROM final where Change is null
Use a CASE expression:
SELECT Name, NameSimple, DirectUse, Year, Month,
CASE WHEN Change IS NULL THEN DirectUse ELSE Old END AS Old,
CurrentCons, Change
FROM final;
I think you basically you want:
SELECT
ColumnA
, CASE WHEN ColumnA IS NULL THEN ColumnC ELSE ColumnB END AS ColumnB
, ColumnC
, <any other columns>
FROM Final
I need to check if one or many fields already exists in a table so I can do a merge into statement using them.
I tried this:
select sat_sector_hkey,
CASE
WHEN EXISTS(select id from hub_sector)
THEN (MERGE INTO ...)
END AS id
from sat_sector;
For testing, I used only one case statement, and replaced merge into with a THEN...ELSE values:
SELECT sat_sector_hkey,
CASE
WHEN EXISTS(select id from hub_sector)
THEN '1'
ELSE ''
END AS id
FROM sat_sector;
When this field does not exists, the query return an error instead of '':
SQL compilation error: error line 3 at position 23 invalid identifier
'ID'
I am using a CASE, because I need to check if a column exists or not, as I don't know if it exists or not due to some technicalities in our data coming from multiple sources.
Try this:
Construct an object with the full row.
Test if the constructed object has data for "ID".
create or replace temp table maybe_id
as
select 1 x, 2 id;
select *,
case
when object_construct(a.*):ID is not null
then '1'
else ''
end as id
from maybe_id a
;
Works for me - it gives 1 when the column id has data, and `` when the column doesn't exist in the table.
I want to assign Valid Column value to a Variable if the entire result set is valid. so need to write the SQL query that checks the entire result set if the column value is valid(not null and not empty) then assign first column value to that variable else check second column with same condition and assign to variable.
For Example: If my Table has column FirstName with 100 records, I need to check Whether all the records are valid(not null or not empty) records suppose 99th record is empty then I need to check LastName column and assign it to a variable.
Thanks in advance.
You can use CASE:
SELECT
CASE
WHEN FirstName IS NULL OR FirstName = '' THEN ISNULL(LastName, '')
ELSE FirstName END
FROM
Tbl
you can use If exists to determine if the column is valid:
if not exists (select 1 from table where col1 is null)
begin
select top(1) col1 from table
end
I have a Table BoxTrans
the table Contain Rows (ID,Date,FromBox,ToBox,Value)
I want to make a View like (ID,Date,Box,ValueIn,ValueOut)
select when frombox Give Value to ValueOut
and when tobox Give Value to ValueIN
You can use a CASE statement to check the value of a different column when populating a column. The below query will return your output as long as either ToBox or FromBox is NULL, if they are both not null you may get unexpected results.
SELECT ID,
Date,
COALESCE(ToBox,FromBox) as Box,
CASE WHEN ToBox IS NOT NULL THEN value ELSE NULL as ValueIn,
CASE WHEN FromBox IS NOT NULL THEN value ELSE NULL as ValueOut
FROM BoxTrans
I want to generate a SQL query to get null count in a particular column like
SELECT COUNT (column) AS count
FROM table
WHERE column = null ;
This is returning 0, but I want how many null values are present in that column like
SELECT COUNT (column) AS count
FROM table
WHERE column = 'some value';
which returns the count of the matched records
NULL value is special in that you cannot use = with it; you must use IS NULL instead:
SELECT COUNT (*) AS count FROM table where column IS null ;
This is because NULL in SQL does not evaluate as equal to anything, including other NULL values. Also note the use of * as the argument of COUNT.
You can use a conditional sum()
SELECT sum(case when column is null
then 1
else 0
end) AS count
FROM table
A different query but exact answer check it out
select count(*)-count(column) from table
please vote check this as answer if it helps you
To get exact output you can use below command as well -
SELECT COUNT (*) AS count FROM table where column IS null OR column='';
because some times only '' doesn't counted as NULL.