I am trying to query the database for checking if a specific column has a value or not. If there is a value in that column, the query should return 1, else it should return 0.
But my query is returning the total count of the columns for (ex:10).
Note: query is done in Dell Boomi integration platform, SQL Server.
select count (*)
from ApplicationRequest
where EmpID = '993685' and ApplID = '1';
Do you just want case?
select (case when count(*) > 0 then 1 else 0 end)
from ApplicationRequest
where EmpID = 993685 and ApplID = 1;
I removed the single quotes around the comparisons. If they are really numbers then single quotes are not appropriate. If they are indeed strings, then use the single quotes.
If this is what you want, a more efficient method would use exists:
select (case when exists (select 1
from ApplicationRequest
where EmpID = 993685 and ApplID = 1
)
then 1 else 0
end)
The aggregation query needs to find all matching rows. This version can stop at the first one.
Related
I work in SQL Teradata.
I would liek to count how many rows (clients) have rounded value in column "amount" (means for example 140.00 not 157.76 and so on). I use code like below:
select
client_id,
count(amount mod 1 = 0)
from table
group by client_id
Nevertheless, I have an error like: SELECT Failed. 3706: Syntax error: expected something between an integer and '='.
What can I do ?
Use a case expression:
sum(case when amount mod 1 = 0 then 1 else 0 end)
I'm not 100% sure if Teradata supports mod 1. I would normally write this as:
sum(case when amount = floor(amount) then 1 else 0 end)
To generate 1mln rows of report with the below mentioned script is taking almost 2 days so, really appreciate if somebody could help me with different script which the report can be generated within 10-15mins please.
The requirement of the report is as following;
Table “cover” contains 5mln rows & 6 columns of data and likewise table “data” contains 500,000 rows and 6 columns.
So, each numbers of the rows in table cover has to go through table date and provide the maximum matches.
For instance, as mentioned on the below tables, there could be 3 matches in row #1, 2 matches in row #2 and 5 matches in row #3 so the script has to select the max selection which is 5 in row #3.
Sample table
UPDATE public.cover_sheet AS fc
SET maxmatch = (SELECT MAX(tmp.mtch)
FROM (
SELECT (SELECT CASE WHEN fc.a=drwo.a THEN 1 ELSE 0 END) +
(SELECT CASE WHEN fc.b=drwo.b THEN 1 ELSE 0 END) +
(SELECT CASE WHEN fc.c=drwo.c THEN 1 ELSE 0 END) +
(SELECT CASE WHEN fc.d=drwo.d THEN 1 ELSE 0 END) +
(SELECT CASE WHEN fc.e=drwo.e THEN 1 ELSE 0 END) +
(SELECT CASE WHEN fc.f=drwo.f THEN 1 ELSE 0 END) AS mtch
FROM public.data AS drwo
) AS tmp)
WHERE fc.code>0;
SELECT *
FROM public.cover_sheet AS fc
WHERE fc.maxmatch>0;
As #a_horse_with_no_name mentioned in the comment to the question, your question is not clear...
Seems, you want to get the number of records which 6 fields from both tables are equal.
I'd suggest to:
reduce the number of select statements, then the speed of query execution will increase,
split your query into few smaller ones (good practice), to check your logic,
use join to get equal data, see: Visual Representation of SQL Joins
use subquery or cte to get result on which you'll be able to update table.
I think you want to get result as follow:
SELECT COUNT(*) mtch
FROM public.cover_sheet AS fc INNER JOIN public.data AS drwo ON
fc.a=drwo.a AND fc.b=drwo.b AND fc.c=drwo.c AND fc.d=drwo.d AND fc.e=drwo.e AND fc.f=drwo.f
If i'm not wrong and above query is correct, the time of execution of above query will reduce to about 1-2 minutes.
Finally, update query may look like:
WITH qry AS
(
-- proper select statement here
)
UPDATE public.cover_sheet AS fc
SET maxmatch = qry.<fieldname>
FROM qry
WHERE fc.code>0 AND fc.<key> = qry.<key>;
Note:
I do not see your data and i know nothing about its structure, relationships, etc. So, you have to change above query to your needs.
I`m trying to make a querie that selects users and if user type equals 1 I need to select those with age. My table:
id (int 11) | type (int 11) | email (varchar 25) | age (int 11)
My querie:
SELECT * FROM users WHERE IF(type = 1, age <> 0)
The problem is that I need to have an ELSE condition, but I dont need one in this case. How can I make an IF inside WHERE without else condition?
Thanks
You can do it with CASE:
SELECT * FROM users
WHERE age = CASE WHEN type <> 1 THEN age ELSE 0 END
Q: How do I make IF without ELSE on SQL WHERE condition ?
A: It's not possible; there is always an ELSE. MySQL IF() function has three arguments. It doesn't matter where the IF() function is used, whether it's part of an expression in a WHERE clause, or an expression in the SELECT list.
As an alternative to the MySQL IF() function, we can use a more portable, more ANSI-standard compliant CASE expression. But that doesn't get away from the crux of the question, about avoiding an ELSE. There is always an ELSE with the CASE expression as well. If we omit the ELSE clause, it's the same as if we had specified ELSE NULL.
As an aside (unrelated to the question that was asked), I don't think we should be storing age as an attribute; typically age is the difference between the current date and a date in the past (date of birth, registration date, etc.)
I'm thinking we don't need an IF function in the WHERE clause. (That's specific to MySQL, so this answer assumes that the target DBMS is MySQL, and not some other RDBMS).
We can use a combination of conditions, combined with NOT, AND, OR and parens so specify an order of operations.
Sample data and example output goes a long way to explaining the spec.
id type age email
-- ---- ---- ----------
1 0 0 1#one
2 1 0 2#two
3 0 1 3#three
4 1 1 4#four
5 0 NULL 5#five
6 1 NULL 6#six
7 NULL NULL 7#seven
8 NULL 0 8#eight
9 NULL 1 9#nine
Which of these rows should be returned, and which rows should be excluded?
Here is an example query (MySQL specific syntax) that returns all rows except row id=2 (type=1, age=0)
SELECT u.id
, u.type
, u.age
, u.email
FROM user u
WHERE NOT ( u.type <=> 1 )
OR NOT ( u.age <=> 0 )
If there's a requirement to incorporate IF functions, we can do that, and return an equivalent result:
SELECT u.id
, u.type
, u.age
, u.email
FROM user u
WHERE NOT ( IF( u.type <=> 1 ,1,0) )
OR NOT ( IF( u.age <=> 0 ,1,0) )
^^^ ^^^^^
In the WHERE clause, an expression will be evaluated as a boolean value. A numeric value of 0 is FALSE, a non-zero value is TRUE, and NULL value is (as always) just NULL.
For a row to be returned, we need the expression in the WHERE clause to evaluate to a non-zero value (to evaluate to TRUE).
The third argument of the IF() function is the "else" value; for that value, we can return TRUE, FALSE or NULL. To exclude rows that do not satisfy the type=1 condition, we return either zero or NULL:
WHERE IF(type = 1, age <> 0 ,0 )
^^
or equivalently:
WHERE IF(type = 1, age <> 0 ,NULL )
^^^^^
If we want rows that don't satisfy type=1 condition to be returned, we can return any non-zero value:
WHERE IF(type = 1, age <> 0 ,42 )
^^^
RECAP:
Addressing the question that was asked:
Q: How do I make IF without ELSE on SQL WHERE condition ?
A: There is always an ELSE value with the MySQL IF() function; in the context of the WHERE clause, the value will be evaluated as a boolean: TRUE, FALSE or NULL.
I think you want:
SELECT *
FROM users
WHERE type <> 1 OR age <> 0;
I was in a similar situation and ended up with the following solution:
SELECT * FROM users WHERE IF(type = 1, age <> 0, 1=0)
The else part here is 1 = 0 which is never true, so you don't select anything in that case.
Using Microsoft SQL Server, if you use COUNT(column name) it returns the number of rows in that column which have a non-null value (i.e., it counts the rows, ignoring nulls).
Is there any way to do something similar, but allowing you to tell it which values to ignore? For example, if I wanted to count all the rows in a table which have a value which is NOT 1, I could do something like COUNTNOT(column name,1). That would count all the rows in the specified column which have a value NOT 1.
You may use conditional aggregation:
SELECT COUNT(CASE WHEN some_val <> 1 THEN 1 END) AS cnt
FROM yourTable;
The above logic is that COUNT will count one whenever some value is not equal to 1. Otherwise, it falls on the ELSE conditional, which if not present defaults to the value NULL. Since NULL is not counted, any value other than 1 would contribute zero to the count.
Why not put what you want to exclude in a WHERE clause?
SELECT COUNT(some_val) AS cnt
FROM yourTable
WHERE some_val <> 1
You need to be careful about NULL values. I would recommend:
select sum(case when column in (<values to ignore>) then 0 else 1 end)
This will count NULL values as not in the list (even if NULL is in the list). To ignore NULL values (as well), switch the logic to:
select sum(case when column not in (<values to ignore>) then 1 else 0 end)
and be sure NULL is not in the list.
Please help me with below query , I want to check if string is starts with 'G' or 'F' in where condition along with existing condition. here is the query
first query :-
SELECT Top 1 LC_ID, ISNULL(LC_UD, 0) as Record
FROM CONTRACT
WHERE LC_ID = 'F01'
output
F01 | 1 ( if available) else no record will be return.
second query:
IF LC_ID starts with 'F%' or 'G%'
How i can integrate both the query into one so that if there is no record available for 'F01' value, it will check if LC_ID starts with F & G then return
output
F04 | 1
else no record will be return.
You want to prioritize the values being returned. Because you want only one, you can do this with ORDER BY:
SELECT Top 1 LC_ID, COALESCE(LC_UD, 0) as Record
FROM CONTRACT
WHERE LC_ID LIKE '[FG]%'
ORDER BY (CASE WHEN LC_ID = 'F01' THEN 1 ELSE 2 END);
Note: This assumes you are using SQL Server (based on the syntax).
#gordon's answer is clever, though probably specific to Sql Server. Here's a different approach. The "Top 1" feature is also sql server, but could be avoided through additional techniques.
SELECT Top 1 LC_ID, ISNULL(LC_UD, 0) as Record
FROM CONTRACT
WHERE LC_ID = 'F01'
UNION
SELECT Top 1 LC_ID, ISNULL(LC_UD,0) As Record
FROM CONTRACT
WHERE NOT EXISTS (SELECT * FROM CONTRACT WHERE LC_ID = 'F01')
AND LC_ID LIKE '[FG]%'