Is it possible in SQL to show duplicate records in a result only once.
So instead of this
my#email.com | Some Unique Data | Unique Data
my#email.com | Some Unique Data | Unique Data
my#email.com | Some Unique Data | Unique Data
my#email.com | Some Unique Data | Unique Data
I would get this
my#email.com | Some Unique Data | Unique Data
| Some Unique Data | Unique Data
| Some Unique Data | Unique Data
You should not be using SQL to perform presentational tasks. Any solution to do so is going to be very hacky and require cursors / some other iterative approach.
Almost every report authoring tool has a way to hide duplicates.
simply you can do this --
there are so many option or answer available for this.
one of these is as follow--
select
case
when b.c_1 = 1 then
b.col1
else
null
end col1,
b.col2 col2,
b.col3 col3
from
(
select distinct col1,col2,col3, rownum() over(partition by col1) c_1 from table_name
)b
now assume / modify above query -
table_name is the table name
col1 , col2 and col3 is your table's column name.
just modify this query as per your table name and structure and see..
it would be your required solution.
I know that this is an old question but thought this might be of use to other people. After researching this for awhile, there is a keyword called DISTINCT that will show duplicate values in a query only once. I was using a query to auto-suggest values in a text box on a web page and didn't want it to show duplicate names and this worked for me:
SELECT DISTINCT FIRSTNAME
FROM TBLSTUDENTS
WHERE FIRSTNAME LIKE '#ucase(arguments.search)#%'
Related
How to get a unique, identical value of a table?
For example, if there are tables like 't_aa', 't_bb', 't_cc', I want a result like below.
id | table_name
-------------------
1 | 't_aa'
2 | 't_bb'
3 | 't_cc'
What I exactly want is to get a specific, and unique number from the name of tables.
I have tried
SELECT * FROM information_schema.tables;
-- or
SELECT * FROM pg_catalog.pg_tables;
but this doesn't provide any identical numbers to me.
I hope there is some way to get results like above by using some lines of query,
but if I really have to make a new table for this, that could be okay as an alternative.
please help me, thank you
-- edit
I need numbers because I will use it as an advisory lock key for some reasons.
ThIs is it:
SELECT table_name,ROW_NUMBER () OVER (
ORDER BY table_name
) as id FROM information_schema.tables;
I have a many to many relation table in which I need to insert rows.
Suppose the headers Are:
Table1: Id_1 | Etc....
Table2: Id_2 | Etc....
Relation_Table: Id_1 | Id_2 | Etc.
I need to do the following:
Insert a new element in table 1
Link this new element to all elements in table 2
So, I need to add in the relation table, n rows as the following:
(id_1_new, id_2_0),
(id_1_new, id_2_1),
(id_1_new, id_2_2),
(id_1_new, id_2_3),
(id_1_new, id_2_4),
(id_1_new, id_2_5),
(id_1_new, id_2_6),....
Where id_1_new is known and may be entered manually
And id_2_n may come from select Id_2 from Table2.
How can I do this using SQL statements?
Microsoft Access solutions are welcome as well.
you can use insert... select syntax in order to select the data from the second table to your relation table, using the new id as const in the select :
insert into Relation_table (Id_1, Id_2)
select 'id_1_new' as Id_1, Id_2 from Table2;
Suppose there is a table which has several identical rows. I can copy the distinct values by
SELECT DISTINCT * INTO DESTINATIONTABLE FROM SOURCETABLE
but if the table has a column named value and for the sake of simplicity its value is 1 for one particular item in that table. Now that row has another 9 duplicates. So the summation of the value column for that particular item is 10. Now I want to remove the 9 duplicates(or copy the distinct value as I mentioned) and for that item now the value should show 10 and not 1. How can this be achieved?
item| value
----+----------------
A | 1
A | 1
A | 1
A | 1
B | 1
B | 1
I want to show this as below
item| value
----+----------------
A | 4
B | 2
Thanks in advance
You can try to use SUM and group by
SELECT item,SUM(value) value
FROM T
GROUP BY item
SQLfiddle:http://sqlfiddle.com/#!18/fac26/1
[Results]:
| item | value |
|------|-------|
| A | 4 |
| B | 2 |
Broadly speaking, you can just us a sum and a GROUP BY clause.
Something like:
SELECT column1, SUM(column2) AS Count
FROM SOURCETABLE
GROUP BY column1
Here it is in action: Sum + Group By
Since your table probably isn't just two columns of data, here is a slightly more complex example showing how to do this to a larger table: SQL Fiddle
Note that I've selected my rows individually so that I can access the necessary data, rather than using
SELECT *
And I have achieved this result without the need for selecting data into another table.
EDIT 2:
Further to your comments, it sounds like you want to alter the actual data in your table rather than just querying it. There may be a more elegant way to do this, but a simple way use the above query to populate a temporary table, delete the contents of the existing table, then move all the data back. To do this in my existing example:
WITH MyQuery AS (
SELECT name, type, colour, price, SUM(number) AS number
FROM MyTable
GROUP BY name, type, colour, price
)
SELECT * INTO MyTable2 FROM MyQuery;
DELETE FROM MyTable;
INSERT INTO MyTable(name, type, colour, price, number)
SELECT * FROM MyTable2;
DROP TABLE MyTable2;
WARNING: If youre going to try this, please use a development environment first (i.e one you don't mind breaking!) to ensure it does exactly what you want it to do. It's imperative that your initial query captures ALL the data you want.
Here is the SQL Fiddle of this example in action: SQL Fiddle
I have a sparse table structured like:
id | name | phone | account
There is no primary key or index
There are also null values. What I want is to "glue" data from different rows together, e.g.:
Given
id | name | phone | account
1 null '339-33-27' 4
null 'John' '339-33-27' 4
I want to end up with
id | name | phone | account |
1 'John' '339-33-27' 4
However, I don't know which values are missed in the table.
What are the general way to approach this kind of problem? Do I need to use only joins or might be recursive functions?
Update: Provided more clear example
id to account is many-to-many
account to name is many-to-many
phone to name is one-to-one
The database is basically raw transactional data
What I want to is to get all the rows for which I already have / could find an account
If I understand you correctly then this might work. What you need is a self join
select t2.id, t1.name, t1.phone, t1.account
from table1 t1
join table1 t2 on t1.account = t2.account and t1.phone = t2.phone
where t1.name is not null
However this particular query relies on an assumption from your example data. My assumption is that if name is not null, Id will be null and the Id can be found by looking at the phone number and account. If this assumption is not true , then we may need more sample data to solve your problem.
Depending on the data, you might need left joins or to swap so that T1 gets the id and not the name and the where condition is that ID is not null. It's hard to tell with such a small data sample size.
This is staight forward I believe:
I have a table with 30,000 rows. When I SELECT DISTINCT 'location' FROM myTable it returns 21,000 rows, about what I'd expect, but it only returns that one column.
What I want is to move those to a new table, but the whole row for each match.
My best guess is something like SELECT * from (SELECT DISTINCT 'location' FROM myTable) or something like that, but it says I have a vague syntax error.
Is there a good way to grab the rest of each DISTINCT row and move it to a new table all in one go?
SELECT * FROM myTable GROUP BY `location`
or if you want to move to another table
CREATE TABLE foo AS SELECT * FROM myTable GROUP BY `location`
Distinct means for the entire row returned. So you can simply use
SELECT DISTINCT * FROM myTable GROUP BY 'location'
Using Distinct on a single column doesn't make a lot of sense. Let's say I have the following simple set
-id- -location-
1 store
2 store
3 home
if there were some sort of query that returned all columns, but just distinct on location, which row would be returned? 1 or 2? Should it just pick one at random? Because of this, DISTINCT works for all columns in the result set returned.
Well, first you need to decide what you really want returned.
The problem is that, presumably, for some of the location values in your table there are different values in the other columns even when the location value is the same:
Location OtherCol StillOtherCol
Place1 1 Fred
Place1 89 Fred
Place1 1 Joe
In that case, which of the three rows do you want to select? When you talk about a DISTINCT Location, you're condensing those three rows of different data into a single row, there's no meaning to moving the original rows from the original table into a new table since those original rows no longer exist in your DISTINCT result set. (If all the other columns are always the same for a given Location, your problem is easier: Just SELECT DISTINCT * FROM YourTable).
If you don't care which values come from the other columns you can use a (bad, IMHO) MySQL extension to SQL and do:
SELECT * FROM YourTable GROUP BY Location
which will give a result set with one row per location and values for the other columns derived from the original data in an undefined fashion.
Multiple rows with identical values in all columns don't have any sense. OK - the question might be a way to correct exactly that situation.
Considering this table, with id being the PK:
kram=# select * from foba;
id | no | name
----+----+---------------
2 | 1 | a
3 | 1 | b
4 | 2 | c
5 | 2 | a,b,c,d,e,f,g
you may extract a sample for every single no (:=location) by grouping over that column, and selecting the row with minimum PK (for example):
SELECT * FROM foba WHERE id IN (SELECT min (id) FROM foba GROUP BY no);
id | no | name
----+----+------
2 | 1 | a
4 | 2 | c