#transact sql

SQL Logical Order of Operations

Following is SQL statement’s Logical Order of Operations:

FROM

WHERE

GROUP BY

Aggregations (COUNT, MAX, etc)

HAVING

WINDOW

SELECT

DISTINCT

UNION, INTERSECT, EXCEPT

ORDER BY

OFFSET

LIMIT, FETCH, TOP

That is why, running following SQL statement in SQL Server:

SELECT FirstName, LastName, COUNT(*) FROM dbo.User GROUP BY FirstName

Will throw:

Column ‘dbo.User.LastName’ is invalid in the select list…

Crear una tabla en sql

create table tmp_prueba(

texto1 varchar(10)

,texto2 varchar(10)

,texto3 varchar(10)

,texto4 varchar(10)

,texto6 varchar(10)

,texto7 varchar(10)