Declárate

Introducción a SQL Server

John MacKintosh

Instructor

Variables

SELECT * 
FROM artist 
WHERE name = 'AC/DC';

Ahora cambia la consulta por otro artista:

SELECT * 
FROM artist 
WHERE name = 'U2';

Para evitar repetir, crea una variable:

SELECT * 
FROM artist 
WHERE name = @my_artist;

DECLARE

DECLARE @

Variable entera:

DECLARE @test_int INT

Variable varchar:

DECLARE @my_artist VARCHAR(100)

SET

Variable entera:

DECLARE @test_int INT

SET @test_int = 5

Asigna un valor a @my_artist:

DECLARE @my_artist  varchar(100)

SET @my_artist = 'AC/DC'

DECLARE @my_artist varchar(100)
DECLARE @my_album varchar(300);

SET @my_artist = 'AC/DC'
SET @my_album  = 'Let There Be Rock' ;

SELECT --
FROM --
WHERE artist = @my_artist
AND album = @my_album;

DECLARE @my_artist varchar(100)
DECLARE @my_album varchar(300);

SET @my_artist = 'U2'
SET @my_album  = 'Pop' ;

SELECT --
FROM --
WHERE artist = @my_artist
AND album = @my_album;

Tablas temporales

SELECT 
  col1, 
  col2, 
  col3 INTO #my_temp_table
FROM my_existing_table 
WHERE 
  -- Conditions

#my_temp_table existe hasta que termine la conexión o la sesión

-- Elimina la tabla manualmente
DROP TABLE #my_temp_table

¡Declaremos algunas variables!

Introducción a SQL Server