sql agregar columna
ALTER TABLE Customers
ADD Email varchar(255);
sqlserver agregar columna a la tabla
ALTER TABLE dbo.doc_exa
ADD column_b VARCHAR(20) NULL,
column_c INT NULL ;
modificar tabla añadir columna
ALTER TABLE table
ADD COLUMN column VARCHAR (255) NOT NULL AFTER column;
columna alter de sql server
ALTER TABLE table_name
ALTER COLUMN column_name new_data_type(size);
crear columna sql server
ALTER TABLE table_name
ADD column_name datatype;
agregar columna a la tabla sql
ALTER TABLE table_name ADD column_name varchar(50);