Query to get a unique for a column

Question

1.00/5 (1 vote)

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Hi,

I have a requirement where we get data something like this from 2 tables
Tag and value are 2 columns.

tag      Value
====     =====
Color    RED
Color    GREEN
Color    BLUE
Theme    PARTY
Theme    Diwali
Theme    Christmas
Theme    Holi

Now,

If I pass red to the query, it must remove all the color tags and it should return something like this:

tag      Value
====     =====
Color    RED
Theme    PARTY
Theme    Diwali
Theme    Christmas
Theme    Holi

I was looking for a SQL query to show a single matched row for the column data.

Just in the above example, When I pass Red to the value column(and also color to the Tag column), Nothing should change, except all the color tags rows must be removed except the one i selected. rest of the data remains same.

this data is being shared from 2 tables.

and the query to retrieve data will be something like this.

SQL

SELECT DISTINCT Make.tag, fest.value FROM Make JOIN fest ON make.ID = fest.ID 
WHERE (fest.ID IS NOT NULL) and ( not fest.ID = '') AND 
( Make.tag = 'color' OR Make.tag = 'Theme') ORDER BY Make.tag, fest.ID;

Thank you!

Posted 30-Oct-15 8:44am

praneeth arnepalli

Updated 30-Oct-15 14:14pm

phil.o

v4

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Comments

Shyam S Singh 30-Oct-15 15:16pm

Hi Praneeth,

Can you provide the actual structure of both tables, would be helpful us to provide demo script to insert the data into it ?

[no name] 30-Oct-15 15:17pm

"from 2 tables":
Please show the two tables in more details with the relevant fields.
Thank you.

OP: I made some formatting changes on your Q. I hope it is ok...

praneeth arnepalli 30-Oct-15 18:42pm

I was looking for a SQL query to show a single matched row for the column data.

Just in the above example, When I pass Red to the value column(and also color to the Tag column), Nothing should change, except all the color tags rows must be removed except the one i selected. rest of the data remains same.

tag Value
==== =====
Color RED
Theme PARTY
Theme Diwali
Theme Christmas
Theme Holi

this data is being shared from 2 tables.

and the query to retrieve data will be something like this.

SELECT DISTINCT Make.tag, fest.value FROM Make JOIN fest ON make.ID = fest.ID
WHERE (fest.ID IS NOT NULL) and ( not fest.ID = '') AND
( Make.tag = 'color' OR Make.tag = 'Theme') ORDER BY Make.tag, fest.ID;

Thank you!

George Jonsson 30-Oct-15 19:24pm

You need to update your question with the structure, and maybe example data, for both tables.
Then someone can test it and help you to create a suitable query.

2 solutions

Solution 2

Based on such small portion of information, my best guess is:

SQL

SELECT m.Tag, f.Value
FROM Make AS m JOIN fest AS f ON m.ID = f.ID 
WHERE m.Tag = @tag AND f.Value=@val
UNION ALL
SELECT m.Tag, f.Value
FROM Make AS m JOIN fest AS f ON m.ID = f.ID
WHERE m.Tag != @tag

Posted 31-Oct-15 6:23am

Maciej Los

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Kuthuparakkal · Accepted Answer · 2015-10-31T01:15:00

Try this:

SQL

SELECT SQ.tag
      ,SQ.value
FROM
(
SELECT DISTINCT
       Make.tag
     , fest.value
     , ROW_NUMBER() OVER (ORDER BY Make.tag, fest.ID) AS RID
FROM Make
JOIN fest
    ON
        make.ID = fest.ID
WHERE
     NULLIF(fest.ID, '') IS NOT NULL
    AND
    ( Make.tag = 'color' OR Make.tag = 'Theme')
)AS SQ
WHERE
     CASE WHEN Tag = 'Color' AND Value = 'RED' THEN 1
          WHEN Tag = 'Theme' THEN 1
          ELSE 0
     END = 1
ORDER BY RID