Select table with name from column value - sql

Question

I have this SQL query
SELECT table_name
INTO #LukaTestTable
FROM information_schema.columns
WHERE column_name = 'GUID'
ORDER BY TABLE_NAME ;
How get the value of the column GUID in all tables with the name from TABLE_NAME?
Or can I get table like?
TABLE_NAME GUID_VALUE

Answer 1

In order to be able to query a table before you know what table you want you have to use dynamic queries. If you have an arbitrary number of tables, in SQL Server you could achieve this with cursors:
DECLARE
#column VARCHAR(256) = 'GUID',
#table VARCHAR(256),
#query VARCHAR(4000);
DECLARE #Tables CURSOR LOCAL FAST_FORWARD
FOR
SELECT TABLE_NAME
FROM INFORMATION_SCHEMA.COLUMNS
WHERE COLUMN_NAME = #column
ORDER BY TABLE_NAME;
OPEN #Tables
FETCH NEXT FROM #Tables INTO #table
WHILE ##FETCH_STATUS = 0
BEGIN
SET #query = 'SELECT ' + #column + ' FROM ' + #table
EXEC(#query)
FETCH NEXT FROM #Tables INTO #table
END
CLOSE #Tables
DEALLOCATE #Tables;
If you're sure your 'GUID' column will have same data type - you can create a temp table and insert to it in WHILE loop and SELECT everything in one go at the end.

Answer 2

You can use dynamic sql like this:
declare #sql varchar(max) = cast (' ' as varchar(max));
select #sql = #sql +
(select ' select GUID from ' + quotename(table_name) + ' union all ' as 'text()'
from #LukaTestTable
for xml path(''));
set #sql = reverse(stuff(reverse(#sql), 1, 10, ''));
--print #sql
exec(#sql);
And if you want table_name as e separate column you should first save it in your #LukaTestTable

Answer 3

Try this below script using While loop and dynamic Sql
IF OBJECT_ID('tempdb..#GetSqlQuery') IS NOT NULL
DROP TABLE #GetSqlQuery
IF OBJECT_ID('tempdb..#GetSpecficcolumnvalue') IS NOT NULL
DROP TABLE #GetSpecficcolumnvalue
GO
CREATE TABLE #GetSqlQuery
(
ID INT IDENTITY
,SELECtQuery nvarchar(max)
,TableName varchar(200)
)
CREATE TABLE #GetSpecficcolumnvalue
(
ID INT IDENTITY
,GetValue nvarchar(max)
,TableName varchar(200)
)
INSERT INTO #GetSqlQuery(SELECtQuery,TableName)
SELECT 'SELECT GUID,'''+TABLE_NAME+''' As TableName FROM '+QUOTENAME(TABLE_NAME) AS SELECtQuery,QUOTENAME(TABLE_NAME) AS TableName
FROM(
SELECT
TABLE_SCHEMA,
TABLE_NAME,
COLUMN_NAME
FROM INFORMATION_SCHEMA.COLUMNS
WHERE COLUMN_NAME ='GUID'
)dt
ORDER BY TABLE_NAME
DEclare #MinId INt,#MaxId INT,#Sql nvarchar(maX),#TableName varchar(1000)
SELECT #MinId =MIN(Id),#MaxId=MAX(ID) FROM #GetSqlQuery
WHILE (#MinId<=#MaxId)
BEgin
SELECT #Sql=SELECtQuery ,#TableName=TableName From #GetSqlQuery WHERE ID=#MinId
PRINT #Sql
INSERT INTO #GetSpecficcolumnvalue(GetValue,TableName)
EXEC (#Sql)
SET #MinId=#MinId+1
END
SELECT ROW_NUMBER()OVER(ORDER BY (SELECT 1)) AS Seq,GetValue,TableName
FROM
(
SELECT *, ROW_NUMBER ()OVER(PArtition by GetValue,TableName ORDER BY
TableName) AS dup FROM #GetSpecficcolumnvalue
)dt where dt.dup=1