Count(*) return 1 or zero - sql

In one of the usecase I need a query which should return 1 based on condition also if not match it should return 0
In Descpriont column if the 'SAP' count is exactly 1 then the query should return 1 else it should return 0
Note : There might be a chance that SAP could be present any number of times in Description column.
Could someone help me out here !!
Thanks.
I tried below query :
SELECT 1 from TableName where Description ='SAP' having count(*)>1
It is returning 1 but not return 0 if the count is more than 1 or no match found.

Use CASE WHEN to decide whether to show 0 or 1.
select case when count(*) = 1 then 1 else 0 end as sap_count_is_1
from mytable
where description = 'SAP';

use case when
select
case when sum(case when description='SAP' then 1 else 0 end)=1 then 1 else 0 end from table_name

Related

returning the column values as a list or else 0

I had a query where i am trying to get the results of a query, the query can have multiple rows or it can be empty, i am trying if it is empty, it should return me 0 for a column i am looking which is called as sequence
My query is like this:
select CASE WHEN COUNT(1) > 0 THEN 1 ELSE 0 END AS Sequence
from dbo.mytable
it returns me the either 1 or 0, for 1 i want that column should return me values or it should combine all the rows and return me the value of that column as list like 1,2,3,4,5,6,7
This should work.
SELECT
CASE WHEN MY_COUNT > 0 THEN 1 ELSE 0 END AS SEQUENCE
FROM
(SELECT COUNT(*) AS MY_COUNT
FROM
DBO.MYTABLE);
If you want only one row in the result set, simply do:
select (case when count(*) > 0 then 1 else 0 end) as sequence
from mytable;
If you care at all about performance, the more efficient method is:
select (case when exists (select 1 from dbo.mytable) then 1 else 0
end) as sequence

How to check all records have some value in oracle query?

I have query to check some exists like:
SELECT CASE WHEN (exists (select * from "Customer" where length(CustomerID) >
0) ) then 1 else 0 end val from dual
How do I know all records of Customer table have length of the field(CustomerID) bigger than 3. If all records have value bigger than 3 then 1 or 0 .
Thanks in advance.
Joon
Something like this?
SELECT CASE WHEN MIN(LENGTH(CustomerID)) > 3 THEN 1 ELSE 0 END AS Val
FROM Customer;
Try this.
SELECT CASE
WHEN COUNT(CASE
WHEN LENGTH(CustomerID) > 3
THEN 1
END) = COUNT(*)
THEN 1
ELSE 0
END as res
FROM Customer;
Demo

How to add multiple case in sql

I want to add multiple cases in single line. In other words in below example if first item is NOT NULL and second item is equal to 1 then output should be 1 else 0. How can I do it?
MatchbyCatalog= (case when ISNULL(pc.ProductID,0) and tc.RawMatch=1) then 1 else 0 end)
Is this what you want?
CASE WHEN pc.ProductID IS NULL and tc.RawMatch=1 THEN 1 ELSE 0 END
You misunderstood ISNULL() , it's a function that replaces the value if it's NULL, it's not a condition . You were looking for IS NULL
That's all you need.
MatchbyCatalog= (case when ISNULL(pc.ProductID,0)=1 and tc.RawMatch=1 then 1 else 0 end)
when you say both I think you mean pc.ProductID and tc.RawMatch...
I have not you're entire sql query so I have to guess.
You have multiple solutions :
Nearly ss you have wrote when pc.ProductId = 1 and tc.RawMatch=1 then 1 else 0 :
MatchbyCatalog= (case when ISNULL(pc.ProductID,0)=1 and tc.RawMatch=1) then 1 else 0 end)
You could also use a trick : 1 * 1 should be 1 and 1 * 0 =0 so you could write (if tc.Rawmatch is a boolean sort of with values 0 or 1) :
MatchbyCatalog= ISNULL(pc.ProductID,0) * tc.RawMatch
case when {Condition} then {result}
When {Condition} then {result}
Else {result}

How to check if all rows validate a predicate

I've a table in my database for which I need to check if all rows have one field not null.
If there are no row or if there is at least 1 row with the field null => true
If there are rows and they are all with the field not null => False
Is there a way to do this in on simple query? Or I need to check if my table is empty first then if it's not check if I've a row with the field value empty ?
This will count how many NULL values you have in a field;
SELECT
SUM(CASE WHEN FieldName IS NULL THEN 1 ELSE 0 END) NullValues
FROM TableName
Will return 0 if there are no NULL values, and will return the number of NULLS if there are any present.
If you actually want to return a value as 'True' or 'False' then do this;
SELECT CASE
WHEN a.NullValues > 0
THEN 'True'
ELSE 'False'
END CheckField
FROM (
SELECT
SUM(CASE WHEN FieldName IS NULL
THEN 1
ELSE 0
END) NullValues
FROM TableName
) a
Use count(*) and count(field) and compare the two:
select
case when count(*) > 0 and count(*) = count(field) then 1 -- not empty and no nulls
else 0 end as isgood
from mytable;
Oracle SQL has no boolean data type , so I use 1 for true and 0 for false. You can replace this with whatever you like (e.g. 'true' instead of 1 and 'false' instead of 0).
As to turning this into a predicate (correlated to a main query), you'd use something along the lines of:
select ...
from main
where exists
(
select 1
from mytable
where mytable.colx = main.coly
having count(*) > 0 and count(*) = count(field)
);
You can do this with aggregation. However, it is difficult to understand what you are asking for. If you want to check that a field has no NULL values, you can do:
select (case when count(*) > 0 then 1 else 0 end) as HasNullValues
from t
where field is null;
Alternate way I found using max with putting null first:
select case when
max(field) keep (dense_rank first order by datfin desc nulls first) is null then 1
else 0 end as flag
from MYTABLE;

Even or odd in SQL

This is table structure
id
1
2
3
4
5
6
I need result like this
id even odd
1 0 1
2 1 0
3 0 1
4 1 0
5 0 1
6 1 0
I tried
select id %2=0 then 1 else 0 end or id%2 <>0 then 1 else 0 odd
from table
How about
select
id,
~id & 1,
id & 1
from t
Take a look at the CASE keyword. It works very similarly to what you're trying to do in your SELECT statement. In addition, if you want to select multiple columns, separate them with a comma. The OR keyword is used for combining logical conditions in your query, not for specifying multiple columns.
An example of how you could use CASE in your query would be as follows:
SELECT id,
CASE WHEN id %2=0 THEN 1 ELSE 0 END AS Even,
[column2]
FROM [TableName]
The table structure is just Id?
you could try this!
select *,
case when id %2=0 then 1 else 0 end as even,
case when id %2 <>0 then 1 else 0 end as odd
from table
You have the right idea, but your syntax is a bit off. I'd use a CASE statement to create the even column, and then a calculate odd accordingly:
SELECT id, even, ABS(even - 1) AS odd
FROM (SELECT id, CASE WHEN id % 2 = 0 THEN 1 ELSE 0 END AS even
FROM my_table)