I have such values in the letter column:
A, B, C, D, E, **X**.
I would like the select to return to me such an order of
A, B, **X**, C, D, E.
I tried with ORDER BY, but I don't know if it's a good way, or it should be SELECT Top 2 and next...
If it's only one character:
order by case when MyColumn < 'C' then 1
when MyColumn = 'X' then 2
else 3
end,
MyColumn
In this case you should assign a numeric value to each of the possible values in order to get them in the desired way. It could be something like
order by case when column = 'A' then 1
when column = 'B' then 2
when column = 'C' then 3
when column = 'X' then 4
...
else 99999999
end
This can be done using a case expression to re-position the 'X' between 'B' and 'C' as follows.
order by case when MyColumn = 'X' then 'BB' else MyColumn end
Related
I want to do something like this:
select a
from table
order by
case when a='A' then b,c,d
else d,c,b
a, b, c, d are all columns of the the table.
Your question is not that clear about the result that you really expect, bu I suspect that is:
order by
case when a = 'A' then b else d end,
c,
case when a = 'A' then d else b end
Or if you want records where a = 'A' first (with the specified order), and then the rest of the records (with the other sequence), then:
order by
case when a = 'A' then 0 else 1 end,
case when a = 'A' then b else d end,
c,
case when a = 'A' then d else b end
Lets say I have the following table:
FKEY A B C D E F
'A' 1 0 1 0 1 0
'A' 0 1 1 1 0 0
Now i want to make a group by FKEY but I just want to know if the A-F columns has 1 in one, all or none of the grouped rows.. The resulton the above table would be:
FKEY A B C D E F
'A' S S A S S N
..where S is "some", A is "all" and N is "none".
What would be the best approach to make this query. I could so some nested queries, but isnt there a smarter way?
In my real life data, the 1's and 0's are actually DATETIME and NULL's
You can use case and aggregation:
select fkey,
(case when sum(a) = 0 then 'N'
when sum(a) = count(*) then 'A'
else 'S'
end) as a,
(case when sum(b) = 0 then 'N'
when sum(b) = count(*) then 'A'
else 'S'
end) as b,
. . .
from t
group by fkey;
The above assumes that the values are only 0 and 1. If that is the case, you can actually phrase this as:
(case when max(a) = 0 then 'N'
when min(a) = 1 then 'A'
else 'S'
end) as a,
You mentioned that your 0 and 1 are actually null or non null dates. Here's a modified version of Gordon's query that caters for that:
select fkey,
(case when count(datecol) = 0 then 'all dates are null'
when count(datecol) = count(*) then 'all dates are filled'
else 'some are null, some filled'
end) as a,
...
from t
group by fkey;
COUNT(null) is 0, COUNT('2001-01-01') is 1, COUNT(*) is the row count independent of any variable. Hence, if our count of the dates was 0, all must be null. If the count of the dates was equal to the count of the rows, then all must be filled with some value, otherwise it's a mix
I have six unique columns (let's just call them A, B, C, D, E, F) that all have either YES or NULL as the value. In a new column (let's call it NEW) I need to input the column name (A, B, C, D, E, F) if the value is YES. I also need these values to be concatenated, separated by a comma.
I've been playing around with SELECT/CASE/IF/THEN/ELSE statements, but haven't had any success.
Any guidance that can be offered is appreciated.
You can use CONCAT:
SELECT CONCAT( CASE WHEN A = 'YES' THEN 'A' END,
',' + CASE WHEN B = 'YES' THEN 'B' END,
',' + CASE WHEN C = 'YES' THEN 'C' END,
',' + CASE WHEN D = 'YES' THEN 'D' END,
',' + CASE WHEN E = 'YES' THEN 'E' END) NEW
FROM dbo.YourTable
;
I am trying to get a count on values that might appear in 3 different columns but only require the count of unique values. Microsoft SQL.
Eg. value X might appear in column A, B, or C or all 3 but need to make sure I only get a unique count of value X no matter what columns it comes under.
Thanks!
If you want to count each individual occurrence of X in any column A, B, or C, then the following should work:
SELECT
SUM(CASE WHEN A = 'X' THEN 1 ELSE 0 END) +
SUM(CASE WHEN B = 'X' THEN 1 ELSE 0 END) +
SUM(CASE WHEN C = 'X' THEN 1 ELSE 0 END)
FROM yourTable
Is this what you are looking for? This will Count only 1 occurrence per row regardless of how many columns it is found in.
SELECT
ID
,SUM(CASE WHEN ColA = 'X' OR ColB = 'X' OR ColC = 'X' THEN 1 ELSE 0 END) AS ValueCount
FROM
TABLENAME
GROUP BY
ID
I guess I should show it without the group by too because you don't specify a grouping.
SELECT
,SUM(CASE WHEN ColA = 'X' OR ColB = 'X' OR ColC = 'X' THEN 1 ELSE 0 END) AS ValueCount
FROM
TABLENAME
Is it possible to alias a column name and then use that in a CASE statement? For example,
SELECT col1 as a, CASE WHEN a = 'test' THEN 'yes' END as value FROM table;
I am trying to alias the column because actually my CASE statement would be generated programmatically, and I want the column that the case statement uses to be specified in the SQL instead of having to pass another parameter to the program.
This:
SELECT col1 as a,
CASE WHEN a = 'test' THEN 'yes' END as value
FROM table;
...will not work. This will:
SELECT CASE WHEN a = 'test' THEN 'yes' END as value
FROM (SELECT col1 AS a
FROM TABLE)
Why you wouldn't use:
SELECT t.col1 as a,
CASE WHEN t.col1 = 'test' THEN 'yes' END as value
FROM TABLE t;
...I don't know.
I think that MySql and MsSql won't allow this because they will try to find all columns in the CASE clause as columns of the tables in the WHERE clause.
I don't know what DBMS you are talking about, but I guess you could do something like this in any DBMS:
SELECT *, CASE WHEN a = 'test' THEN 'yes' END as value FROM (
SELECT col1 as a FROM table
) q
#OMG Ponies - One of my reasons of not using the following code
SELECT t.col1 as a,
CASE WHEN t.col1 = 'test' THEN 'yes' END as value
FROM TABLE t;
can be that the t.col1 is not an actual column in the table. For example, it can be a value from a XML column like
Select XMLColumnName.value('(XMLPathOfTag)[1]', 'varchar(max)')
as XMLTagAlias from Table
It should work. Try this
Select * from
(select col1, col2, case when 1=1 then 'ok' end as alias_col
from table)
as tmp_table
order by
case when #sortBy = 1 then tmp_table.alias_col end asc
I use CTEs to help compose complicated SQL queries but not all RDBMS' support them. You can think of them as query scope views. Here is an example in t-sql on SQL server.
With localView1 as (
select c1,
c2,
c3,
c4,
((c2-c4)*(3))+c1 as "complex"
from realTable1)
, localView2 as (
select case complex WHEN 0 THEN 'Empty' ELSE 'Not Empty' end as formula1,
complex * complex as formula2
from localView1)
select *
from localView2
Nor in MsSql
SELECT col1 AS o, e = CASE WHEN o < GETDATE() THEN o ELSE GETDATE() END
FROM Table1
Returns:
Msg 207, Level 16, State 3, Line 1
Invalid column name 'o'.
Msg 207, Level 16, State 3, Line 1
Invalid column name 'o'.
However if I change to CASE WHEN col1... THEN col1 it works
If you write only equal condition just:
Select Case columns1 When 0 then 'Value1'
when 1 then 'Value2' else 'Unknown' End
If you want to write greater , Less then or equal you must do like this:
Select Case When [ColumnsName] >0 then 'value1' When [ColumnsName]=0 Or [ColumnsName]<0 then
'value2'
Else
'Unkownvalue' End
From tablename
Thanks
Mr.Buntha Khin
SELECT
a AS [blabla a],
b [blabla b],
CASE c
WHEN 1 THEN 'aaa'
WHEN 2 THEN 'bbb'
ELSE 'unknown'
END AS [my alias],
d AS [blabla d]
FROM mytable
Not in MySQL. I tried it and I get the following error:
ERROR 1054 (42S22): Unknown column 'a' in 'field list'
In MySql, alice name may not work, therefore put the original column name in the CASE statement
SELECT col1 as a, CASE WHEN col1 = 'test' THEN 'yes' END as value FROM table;
Sometimes above query also may return error, I don`t know why (I faced this problem in my two different development machine). Therefore put the CASE statement into the "(...)" as below:
SELECT col1 as a, (CASE WHEN col1 = 'test' THEN 'yes' END) as value FROM table;
Yes, you just need to add a parenthesis :
SELECT col1 as a, (CASE WHEN a = 'test' THEN 'yes' END) as value FROM table;
make it so easy.
select columnnameshow = (CASE tipoventa
when 'CONTADO' then 'contadito'
when 'CREDITO' then 'cred'
else 'no result'
end) from Promocion.Promocion