SQL | Null Function in SQL | ISNULL | COALESCE | IFNULL | NVL

In this video we see the different NULL functions in SQL and see, when and how to use the NULL functions.
A field with a NULL value is a field with no value. If a field in a table is optional, it is possible to insert a new record or update a record without adding a value to this field. Then, the field will be saved with a NULL value.
Note: A NULL value is different from a zero value or a field that contains spaces.
Table used :
/*
create table product(
item varchar(20),
unitssold int,
unitsonorder int,
unitprice int
)
*/
/*
insert into product(item,unitssold,unitsonorder,unitprice)
values('pen',100,50,20),
('book',200,null,30),
('pencil',150,50,10),
('toys',125,null,40),
('bags',100,25,50)
*/
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[@aceslwin3376]

Very thank you for this NULL Problem solve program.😂😂😂🎉🎉🎉😅😅😅

[@manishprajapat7316]

thanks brother

[@davidestherohunene2137]

How do i write a code to return a value on the formatted date column.
For example, i run a query to change date format from 22/06/25 to change to this format 22-06-25 and the result is null.
What can i do so the date can show and the null value be replaced with real date of the original dataset.
Thank you

[@dataprojecthub]

Hi, I believe the input date column is of string data type. (The following query is based on that assumption)
--try this query
-----------------------------------------------------
select datefromparts([year],[month],[day]) as proper_date --in date data type
from
(
select parsename(replace(date_input,'/','.'),1) as [day],
parsename(replace(date_input,'/','.'),2) as [month],
concat('20',parsename(replace(date_input,'/','.'),3)) as [year]
from
(select '22/06/25' as date_input) a
) b
--------------------------------------------------
Here I have used the date '22/06/25' and wrote the query, but you can substitute the date with the actual input column and table.
Thanks

[@lerishamendonsa3126]

What if have multiple repeated items ,
How to write a query, can you please help me

[@dataprojecthub]

Hi, can you give me an example please.

[@pateldh23]

How to write sql query to sum of specific field if column value is kg then sum in kg and if value is To then quantity * 1000 and then sum plus sum of kg field

[@dataprojecthub]

Hi, actually I did not get the question. Can you please reframe it?

[@pateldh23]

@@dataprojecthub suppose I have one table in sql server, cloumns like dt_data_date, vc_material_code, vc_buom, nu_qty. And suppose in vc_buom column if value is 'TO' Means Tone then qty * 1000 and then sum and then it's sum include in KG Coum sum

[@dataprojecthub]

--this query will create a new column qty_in_kg in which everything will be in kg
select dt_data_date,
vc_material_code,
vc_buom,
nu_qty,
case when vc_buom = 'TO' then (nu_qty*1000)
when vc_buom = 'KG' then nu_qty
end as qty_in_kg
from table_name
--and now if you want to sum up the total quantity based on vc_material_code
--use the below query
select vc_material_code
,sum(qty_in_kg) as total_quantity
from
(
select dt_data_date,
vc_material_code,
vc_buom,
nu_qty,
case when vc_buom = 'TO' then (nu_qty*1000)
when vc_buom = 'KG' then nu_qty
end as qty_in_kg
from table_name
) a
group by vc_material_code