SQL- UNION ALL a large number of tables

Question

I have a large number of tables (some thousands) containing similar data. I would like to run some reports from these. The table names are similar, so I can get a list of table

Answer 1

You can do this with Dynamic SQL

Declare @SQL varchar(max) =''
Select @SQL = @SQL +'Union All Select * From '+Table_Name+' ' 
  FROM INFORMATION_SCHEMA.TABLES
  WHERE TABLE_NAME LIKE 'TableNamePrefix%'
  ORDER BY TABLE_NAME
Set @SQL = Stuff(@SQL,1,10,'')
Exec(@SQL)

Answer 2

select 'select * from  '+TABLE_NAME +' union all'
FROM
 INFORMATION_SCHEMA.TABLES
WHERE TABLE_NAME LIKE '%chd%'
ORDER BY TABLE_NAME

remove last union all

Answer 3

All these tables have the same data types and number of columns, because if this not the case then you will not be able to use UNION sentences, however, it's very strange to merge all the information in this way, could you put some examples to clarify it.

Answer 4

using your pattern on table name - i got somewhere with

DECLARE @SQL nvarchar(max);

select @SQL =  COALESCE(@SQL , '') + 'SELECT * FROM [' +  TABLE_NAME + ']  UNION ALL ' 
FROM INFORMATION_SCHEMA.TABLES where TABLE_NAME LIKE '%employeedet%';

SELECT @SQL = LEFT(@SQL, LEN(@SQL) - 11);

print @SQL;