------------Example Nr 1--------------
--Working querry without variable Table

DECLARE @Sql nvarchar(MAX);
SET @Sql = 'SELECT ';
SELECT @Sql = @Sql +'['+[Modell Pset (S1 Slab)]+']'+ ' AS ''' +''+[C3D Pset (S1 Slab)]+''', ' FROM [MTO_Psets_S1_Slab]
print @sql

--Result of "print @sql": SELECT [c3d:abschnitt] AS 'Abschnitt', [ALL] AS 'Eigenschaft_1', [ALL] AS 'Eigenschaft_2', [Geschoss] AS 'Geschoss', [ALL] AS 'Ist_Aussen', [ALL] AS 'Material_1', [ALL] AS 'Material_2', [ALL] AS 'Objekt', [c3d:teilprojekt] AS 'Teilprojekt',

SET @Sql = (SELECT LEFT(@Sql, LEN(@Sql)-1));
SET @Sql = @Sql + ' FROM [modell_properties_slab]';
EXEC sp_executesql @Sql;



------------Example Nr 2--------------
--When i replace Table with a variable, the querry doesn't work

DECLARE @Sql nvarchar(MAX);
DECLARE @Table nvarchar(MAX);
set @table='[MTO_Psets_S1_Slab]'
SET @Sql = 'SELECT ';
SELECT @Sql = @Sql +'['+[Modell Pset (S1 Slab)]+']'+ ' AS ''' +''+[C3D Pset (S1 Slab)]+''', ' FROM @table
SET @Sql = (SELECT LEFT(@Sql, LEN(@Sql)-1));
SET @Sql = @Sql + ' FROM [modell_properties_slab]';
EXEC sp_executesql @Sql

--Error message: Msg 1087, Level 16, State 1, Line 24 Must declare the table variable "@Table".



------------Example Nr 3--------------
--When i rewrite the querry to have the table inside the apostrophes, it doesn't work (compare the result of "print @sql" with the example nr1)

declare @slab nvarchar(MAX) ='slab'
DECLARE @intermediate_step nvarchar(MAX);
set  @intermediate_step = '''[''[Modell Pset (S1 Slab)]+'']''+ '' AS '''''' +''''+[C3D Pset (S1 Slab)]+'''''', '' FROM [MTO_Psets_S1_'+@Slab+']'
print @intermediate_step

--Result of "print @intermediate_step": '['[Modell Pset (S1 Slab)]+']'+ ' AS ''' +''+[C3D Pset (S1 Slab)]+''', ' FROM [MTO_Psets_S1_slab]

DECLARE @Sql nvarchar(MAX);
SET @Sql = 'SELECT ';
SELECT @Sql = @Sql + @intermediate_step
print @sql
--Result of "print @sql": SELECT '['[Modell Pset (S1 Slab)]+']'+ ' AS ''' +''+[C3D Pset (S1 Slab)]+''', ' FROM [MTO_Psets_S1_slab]

SET @Sql = (SELECT LEFT(@Sql, LEN(@Sql)-1));
SET @Sql = @Sql + ' FROM [modell_properties_slab]';
EXEC sp_executesql @Sql;