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问题:
I have very simple problem that I can't solve. I need to do something like this:
select distinct * from (1, 1, 1, 2, 5, 1, 6).
Anybody can help??
Edit
The data comes as a text file from one of our clients. It's totally unformatted (it's a single, very long line of text), but it may be possible to do so in Excel. But it's not practical for me, because I will need to use these values in my sql query. It's not convenient to do so every time I need to run a query.
回答1:
Simplest way to get the distinct values of a long list of comma delimited text would be to use a find an replace with UNION to get the distinct values.
SELECT 1
UNION SELECT 1
UNION SELECT 1
UNION SELECT 2
UNION SELECT 5
UNION SELECT 1
UNION SELECT 6
Applied to your long line of comma delimited text
- Find and replace every comma with
UNION SELECT
- Add a
SELECT
in front of the statement
You now should have a working query
回答2:
Available only on SQL Server 2008 and over is row-constructor in this form:
You could use
SELECT DISTINCT * FROM (VALUES (1), (1), (1), (2), (5), (1), (6)) AS X(a)
Many wrote about, among them:
- [MS official] https://docs.microsoft.com/en-us/sql/t-sql/queries/table-value-constructor-transact-sql
- http://www.sql-server-helper.com/sql-server-2008/row-value-constructor-as-derived-table.aspx
回答3:
In general :
SELECT
DISTINCT
FieldName1, FieldName2, ..., FieldNameN
FROM
(
Values
( ValueForField1, ValueForField2,..., ValueForFieldN ),
( ValueForField1, ValueForField2,..., ValueForFieldN ),
( ValueForField1, ValueForField2,..., ValueForFieldN ),
( ValueForField1, ValueForField2,..., ValueForFieldN ),
( ValueForField1, ValueForField2,..., ValueForFieldN )
) AS TempTableName ( FieldName1, FieldName2, ..., FieldNameN )
In your case :
Select
distinct
TempTableName.Field1
From
(
VALUES
(1),
(1),
(1),
(2),
(5),
(1),
(6)
) AS TempTableName (Field1)
回答4:
Have you tried using the following syntax?
select * from (values (1), (2), (3), (4), (5)) numbers(number)
回答5:
If you want to select only certain values from a single table you can try this
select distinct(*) from table_name where table_field in (1,1,2,3,4,5)
eg:
select first_name,phone_number from telephone_list where district id in (1,2,5,7,8,9)
if you want to select from multiple tables then you must go for UNION
.
If you just want to select the values 1, 1, 1, 2, 5, 1, 6 then you must do this
select 1
union select 1
union select 1
union select 2
union select 5
union select 1
union select 6
回答6:
PostgreSQL gives you 2 ways of doing this:
SELECT DISTINCT * FROM (VALUES('a'),('b'),('a'),('v')) AS tbl(col1)
or
SELECT DISTINCT * FROM (select unnest(array['a','b', 'a','v'])) AS tbl(col1)
using array approach you can also do something like this:
SELECT DISTINCT * FROM (select unnest(string_to_array('a;b;c;d;e;f;a;b;d', ';'))) AS tbl(col1)
回答7:
This works on SQL Server 2005 and if there is maximal number:
SELECT *
FROM
(SELECT ROW_NUMBER() OVER(ORDER BY a.id) NUMBER
FROM syscomments a
CROSS JOIN syscomments b) c
WHERE c.NUMBER IN (1,4,6,7,9)
回答8:
If you need an array, separate the array columns with a comma:
SELECT * FROM (VALUES('WOMENS'),('MENS'),('CHILDRENS')) as X([Attribute])
,(VALUES(742),(318)) AS z([StoreID])
回答9:
Another way that you can use is a query like this:
SELECT DISTINCT
LTRIM(m.n.value('.[1]','varchar(8000)')) as columnName
FROM
(SELECT CAST('<XMLRoot><RowData>' + REPLACE(t.val,',','</RowData><RowData>') + '</RowData></XMLRoot>' AS XML) AS x
FROM (SELECT '1, 1, 1, 2, 5, 1, 6') AS t(val)
) dt
CROSS APPLY
x.nodes('/XMLRoot/RowData') m(n);
回答10:
I know this is a pretty old thread, but I was searching for something similar and came up with this.
Given that you had a comma-separated string, you could use string_split
select distinct value from string_split('1, 1, 1, 2, 5, 1, 6',',')
This should return
1
2
5
6
String split takes two parameters, the string input, and the separator character.
you can add an optional where statement using value
as the column name
select distinct value from string_split('1, 1, 1, 2, 5, 1, 6',',')
where value > 1
produces
2
5
6
回答11:
A technique that has worked for me is to query a table that you know has a large amount of records in it, including just the Row_Number field in your result
Select Top 10000 Row_Number() OVER (Order by fieldintable) As 'recnum' From largetable
will return a result set of 10000 records from 1 to 10000, use this within another query to give you the desired results
回答12:
Use the SQL In
function
Something like this:
SELECT * FROM mytable WHERE:
"VALUE" In (1,2,3,7,90,500)
Works a treat in ArcGIS