I have table like below:
I want result like even one column is null or empty string those records should not be display.
I want results like below:
select * from WHERE col1 IS NOT NULL AND col2 IS NOT NULL AND col3 IS NOT NULL AND col4 IS NOT NULL AND col5 IS NOT NULL....AND col9 IS NOT NULL
If you wanted an efficient way to do this, then one method would be a persistent computed column:
alter table t
add numNulls as ( (case when col1 is null then 1 else 0 end) +
(case when col2 is null then 1 else 0 end) +
(case when col3 is null then 1 else 0 end) +
. . .
) persisted;
You can index this column:
create index t_numNulls on t(numNulls);
And then you can use this in the select:
select t.*
from t
where num_nulls = 0;
That said, I suspect that your real problem is the data model. I am guessing that those 90 columns are really an "array" -- that is, all the same entity. These should be implemented as separate rows in a junction table.
Related
I have a sql code with filter conditions as below
Select * from TABLE A
Where Col1<>0
and(col2 is not null or col3 is not null)
Please explain why i do not see any records in the output when a record has NULL on both col2 and col3.
How is this is evaluated??
Null check for Col1 should be the first in condition. if Col1 is null then checking null with a value e.g. Col1 = 0 or Col1 <> 0 will always return false. Below an alternate way to deal with nulls in Col1.
Select * from TABLE A
Where isnull(Col1, 0) <> 0
and col2 is not null
Here is the query
select col1
from table
col1 contains these category values:
A
B
C
NULL
How can I rename null category to D?
If you want to make the change permanent
UPDATE table
SET col1 = 'D'
WHERE col1 IS NULL
From then on you can simply query with ...
SELECT col1
FROM table
... to get the desired result.
If there is more than one row having a NULL in col1, you need to filter by a unique key, preferably by the primary key (which every table should have by the way). Let's say you have a table like
id (PK) col1
--- ----
1 'A'
2 'B'
3 'C'
4 NULL
5 NULL
then you can fix it with
UPDATE table SET col1 = 'D' WHERE id = 4;
UPDATE table SET col1 = 'E' WHERE id = 5;
unless you can calculate the new value from another column, e.g.:
UPDATE table
SET col1 = UPPER(LEFT(name, 1))
Try this : ISNULL( ) function is used to replace NULL value with another value
select isnull(col1,'D') as col1
from table
SQL Server uses ISNULL().
SELECT ISNULL(value_to_check, use_this_instead_if_valuetocheck_is_null)
For your code:
select ISNULL(col1, 'D') AS col_name
from table
However, this will happen across the board for this column. You can't use this to make a sequence, like D then E then F. Any NULL value you come across in this column will change to D.
I would like to get to know how I can get the first column with NULL value from the left for each row in my table, I've tried with SELECT CASE but it doesn't work the way I would like.
Guys, I'd like to be crystal-clear about what I want to accomplish. I have a table with 22 columns and there are rows in which last 10 columns have NULL values but I need to get to know only a name of the first column from the left with NULL value.
You get the value from the first non-NULL column using coalesce():
select coalesce(col1, col2, col3, . . .)
You can get the name using case logic:
select (case when col1 is not null then 'col1'
when col2 is not null then 'col2'
. . .
end)
Just specify NULL as your first field selection.
SELECT NULL, FieldA, FieldB, FieldC etc
FROM yourtable
The only general approach here is case statement:
Case
when col1 is null then 'col1'
when col2 is null then 'col2'
when col3 is null then 'col3'
end as frst_null
This way frst_null would contain the name of the first column containing Null value. You can order columns whichever order you like.
I have a table with schema like below:
root
|id
|name
|col1
|col2
|...
|col30
Conditions are that multiple rows can have the same name (they're not primary key - the key is the ID). Values in col1-col30 will be some string, or it can have the string "null".
I'm interested in the number of columns filled in for each name.
For example,
if name "test1" has col1-5 filled in a row, and another row has "test1" and have col1, 3, 10, 6 filled in (and the rest of unfilled columns are just string value "null"), "test1" should have value 9.
I'm pretty new to SQL and have been looking this up.. Please help.
Give this a try:
SELECT
name,
CASE WHEN col1_max IS NOT NULL THEN 1 ELSE 0 END + -- Only include non-NULL values
CASE WHEN col2_max IS NOT NULL THEN 1 ELSE 0 END
FROM (
SELECT
name,
MAX(col1) AS col1_max, -- Non-NULL values come before NULL
MAX(col2) AS col2_max
FROM MyTable
GROUP BY name
) src
You can add more the rest of the columns to fit your case.
Updated
I just realized your NULL case is with a "null" string. Modified:
SELECT
name,
CASE WHEN col1_max IS NOT NULL THEN 1 ELSE 0 END + -- Only include non-NULL values
CASE WHEN col2_max IS NOT NULL THEN 1 ELSE 0 END
FROM (
SELECT
name,
MAX(CASE WHEN col1 = 'null' THEN NULL ELSE col1 END) AS col1_max, -- Non-NULL values come before NULL
MAX(CASE WHEN col2 = 'null' THEN NULL ELSE col2 END) AS col2_max
FROM MyTable
GROUP BY name
) src
First you unpivot your table and count those rows that have not null values. In postgres, you can achieve this with unnest. I have only used col1..7 -- change to upto col30 in your case
WITH t AS(
SELECT id,name,
unnest(array['col1', 'col2', 'col3', 'col4', 'col5', 'col6', 'col7']) AS colname,
unnest(array[col1, col2, col3, col4, col5, col6, col7]) AS colvalue
FROM your_table)
SELECT id, name,
SUM(CASE WHEN colvalue IS NULL THEN 0 ELSE 1 END) AS count_filled
FROM t
GROUP BY 1,2;
My table in Oracle is like this
Col Col1 Col2 Col3 ColR
-- ---- ---- ---- ----
30 73 40 null -10
60 32 null 20 40
90 80 null null 10
80 45 81 30 50
I can also set 0 instead of null in the above column.
I need to find the min value from Col1,Col2,Col3 ignoring null or 0 and populate the ColR by subtracting from Col.
EDIT:
i wrote a CASE statement which doesn't work due to the null values inside my table.
SELECT col,col1,col2,col3,
CASE
WHEN Col1 < Col2 AND Col1 < Col3
THEN Col - Col1
WHEN Col2 < Col1 AND Col2 < Col3
THEN Col - Col2
ELSE Col - Col3
END ColR
FROM
(SELECT col,col1,
CASE
WHEN col22 IS NULL
THEN NULL( i can also SET TO 0 but it will mess WITH my other calculation TO find MIN)
ELSE ROUND( 100* ( (col22) / (col44)))
END col2 ,
CASE
WHEN col33 IS NULL
THEN NULL
ELSE ROUND( 100* ( (col33) / (col44)))
END col3
FROM TABLE
)
I have just included the case statement inside my select query. all the the column values all populated from another query.
It sounds like you want something like
SELECT least( (case when col1 is null or col1 = 0 then 999999999 else col1 end),
(case when col2 is null or col2 = 0 then 999999999 else col2 end),
(case when col3 is null or col3 = 0 then 999999999 else col3 end) )
FROM <<table name>>
where 999999999 is some numeric value that is large enough that it will always be larger than any other valid value. If it is possible that all three columns will have NULL or 0 values, then you'd probably want to add an additional check that if the result of that least function is 999999999 that you return 0 or NULL or whatever else makes sense.
#X-Zero was kind enough to put together a working SQL Fiddle example of this construct. Note that his example is filtering out the rows where all three columns have either NULL or 0 values.
// IF YOU NEED MINIMAL FROM COL1 or COL (ANY COLUMN)
SELECT MIN (COL1) FROM (SELECT * FROM TABLE WHERE COL1 IS NOT NULL)
Can you please elaborate I am not able to help you with this small set of info actually.
Oracle NVL Usage:
nvl(check_expression, replacement_value)
So
nvl(col2,0) ought to take of nulls that mess with your math.
So try:
CASE
WHEN nvl(col1,0) < nvl(col2,0) AND nvl(col1,0) < nvl(col3,0)
THEN Col - nvl(col1,0)
WHEN nvl(col2,0) < nvl(col1,0) AND nvl(col2,0) < nvl(col3,0)
THEN Col - nvl(col2,0)
ELSE Col - nvl(col3,0)
END ColR
EDIT: Taking X-Zero's point which I missed. I think if you replace the NULLS with 9999999 instead of 0, the logic will work, although that may be too specific to this sample data and not a real world solution.
If you want to ignore nulls in a column, you could wrap them with the NVL function. This replaces null values in a column with the value specified, for which you could use some large number. For example:
NVL(col1,99999)
Oracle Database SQL Reference - NVL: http://docs.oracle.com/cd/B19306_01/server.102/b14200/functions105.htm