This question already has answers here:
Exclude a column using SELECT * [except columnA] FROM tableA?
(47 answers)
Closed 5 years ago.
I was reading SQL queries and got stuck with a doubt. Is there any SQL query to exclude a single column while using select statement?
For example, I have a table which contains data about student (s_name, address, email_id, ..... many more).
I want to select all the columns except email_id.
I don't think there is a way to do it directly in a Select statement. But you can use this alternative:
How to select all the columns of a table except one column?
Related
This question already has answers here:
SQL Server dynamic PIVOT query?
(9 answers)
SQL dynamic unpivot table as function
(1 answer)
Closed 2 years ago.
I have table:
I want use UNPIVOT to create table, where CategoryNames rows are columns names.
So, now I can just write this as
SELECT Year, Seafood, Meat/Poultry, [...]
FROM [...] UNPIVOT(...) AS Example
but I don't want write every row manually as column name, so is any option to use
SELECT CategoryName
FROM Pods
query result to create them automatically.
For this example its only 8 row, but with bigger count this could be very helpful.
This question already has answers here:
Why is SELECT * considered harmful?
(16 answers)
Closed 4 years ago.
Suppose I have a table with columns id, name, contact.
What difference is there by getting the data with
SQL query #1:
SELECT *
FROM table
and SQL query #2:
SELECT id, name, contact
FROM table
SELECT * FROM table - its will select all column even if those are useful or not.
if you selecting all the column than some memory overhead and time consuming.
For example , suppose you are selecting all the column and storing in some java object then this is not useful instead of this select those column which is useful for your operation.
This question already has answers here:
SQL Query to concatenate column values from multiple rows in Oracle
(10 answers)
Closed 5 years ago.
I have a table like this:
I need a query (no PL/SQL) that shows this output:
So for each Product ID I want the distinct values of Delivery Type in the field Delivery Type.
Is there a way to get this result through a "simple" query in Oracle?
I am using Oracle 11g.
Thanks in advance !
Use listagg after getting the distinct delivery types per product id. (Note that there is a 4000 character limit for the aggregated string.)
select product_id,listagg(delivery_type,'/') within group (order by delivery_type)
from (select distinct product_id,delivery_type from tbl) t
group by product_id
This question already has answers here:
Randomly Select a Row with SQL in Access
(4 answers)
Closed 7 years ago.
I'm trying to make a Query from my Table "Questions", this table has the following fields: id(auto number), Question(text) ; Category(text), difficulty (number)
The query I'm trying to make must return one random row for every difficulty (1-5), for a given Category.
In SQL you can do something like this:
SELECT TOP 1 * FROM Questions ORDER BY NEWID()
This question already has answers here:
How to exclude a column from SELECT query?
(6 answers)
Closed 9 years ago.
I have 20 column in one table, i want to 18 column and remove 2 column,
mysql query is
SELECT col1,col2,col3,..........,col18 from page;
this query is correct, but 18 column is so larger to written, if any query present just remove 2 column???
SQL does not support a syntax to specify columns to exclude. You must do with it and continue to write explicitly all the columns you want to select. You can also SELECT * but it is often considered bad practices.