Does the result of SELECT MAX([ColumnName]) have a column name? - sql

Does the result of SELECT MAX([ColumnName]) have a column name? I know the result is a view of only one record and I'd thought this view has the original column name as the result column name?

It does not but you can give it one
SELECT MAX([ColumnName]) AS MaxName
If you think about it you will see why your assumption is wrong. What if the code was like this:
SELECT MAX([ColumnName]), MIN([ColumnName])
Which of the two will take the name of the column?

By default no, there is no particular column name. If you specify an alias it will have.
SELECT MAX([ColumnName]) as [max_value_column_name]

Related

Get column names stored in a different table

I have a table that has just a code for the individual column name like "A1G", "Z8H" etc.
This table is a really huge table. Therefore it would not help to manually add the alias name in the SELECT Statement like.
The description for each column code is stored in a different table:
Now I would like to SELECT * from the first table but with the right column header name.
This is stored in the second table within the filters Schema = 'ABC' and Table = 'A'.
That would be desired output:
How would you do that in SQL?
How can I change the column name?
You would be better off just creating a view with all the columns aliased to your preferred names. Once that's done you can select from the view and get the data back with the headings you want.
Look into Inner Join
Or Left Join.

Teradata Character Column with non alphabet values

I have a name column in Teradata that has customer full name all in one column. There are some names with -,_,.,/,#,! in between the name characters. I want to be able to pull records where there are names with these conditions. Is there a better option to pull records with the scenario below?
Currently, I am writing query like this
SELECT NAME FROM TABLESOURCE WHERE NAME LIKE ANY('%-%','%.%','%#%','%~%','%!%')
Thanks in advance.
I haven't tested this but I think you could test for equality when those characters are removed from the name using otranslate
select name
from tablesource
where name <> otranslate(name,'-.#~!','')

Ambiguous column name for order by the selected column

I never notice below before:
SELECT A,*
FROM Table
ORDER BY A
It gives me the Ambiguous column name error. The * of course contains A, but will sql server take the same column A in above query as two different columns? Is this the reason behind that?
it is because the output has the same name if you did
SELECT A AS A_STANDS_ALONE,*
FROM Table
ORDER BY A
It will work
If you are looking for yes/no answer, then 'YES', you are right.
SQL Selects A column twice, one by explicit and one by the implicit * call.
SQL doesn't understand which one you want to sort by.
The first comment to your post shows that you can use an alias for the column.

select where field equals one of multiple values

I want rows but in WHERE I have different values. How can I get these rows? Let's say I want to check names of people with different cnic values?
select name from table where cnic='123','234','134';
It gives me an error. How can I do this?
use mysql In operator for checkinng multiple values.
select name from table `where cnic IN ('123','234','134');
Please use the In operator for this
select name from table where cnic in ('123','234','134')

Get alias name dynamically in Postgresql

I have one table named tblalias.which is having two columns cid, description
cid description
1 Employee
2 Join Date
3 Retire Date
Like this three record is present
Now I have another table tblemployee. I want to write a query for tblemployee to get record but alias name for that query I want should come from tblalias
select nama as Employee,
joindate as "Join Date",
retiredate as "Retire Date"
from tblemployee
If I change value is tblalias table to my select query should return new value as alias is it possible if yes how please help me
The only way to do this is with dynamic SQL. First fetch the alias names then build the final SQL and execute it.
There is no way doing this with a single "hardcoded" statement.
If you want spaces in names you should quote them. (spaces in names is generally a bad Idea, but that's another matter)