Using Sequences with SQL Server - sql-server

Question

I am trying to create a sequence with a table MiCliente the sequence must be eliminate if this exist, must be one by one and with a cycle and it needs to start with 1000. I need to associate the sequence with a column MiCliente.idCliente.
CREATE TABLE dbo.MiCliente
(
idCliente int NOT NULL,
idMunicipio int NOT NULL,
cedula varchar(20) NOT NULL,
nombres varchar(100) NOT NULL,
apellidos varchar(100) NOT NULL,
idSexo char(1) NULL,
idEstadoCivil tinyint NULL,
fechaNacimiento date NULL,
telefono varchar(20) NULL,
celular varchar(20) NULL,
direccion varchar(100) NULL,
email varchar(100) NULL
);
GO
Create Sequence Conteo
AS tinyint
START WITH 1000
INCREMENT BY 1
GO
When I execute the query I receive
error 343

Answer 1

I think maybe an identity field would solve your problem best. You can't really associate a sequence with a table field; at least not by definition. A sequence can be used as a type of "counter" object and can be invoked for a table to generate a value that gets inserted into a table.
(here is a good discussion on using sequences:
https://www.simple-talk.com/sql/learn-sql-server/sql-server-sequence-basics/)
For example, using the sequence you created in your example (keep in mind, as ZLK comments, tinyint is for values from 0 to 255; you should use int) one could say:
select (next value for Conteo) idCliente, cedula, email from dbo.MiCliente;
or something like
INSERT INTO MiCliente
(idCliente, idMunicipio, cedula, nombres, apellidos)
VALUES
(NEXT VALUE FOR Conteo, 1,'test','Smith','test2');
So this works, but one could reference the same sequence for another table as well. So it isn't specifically "tied" to your table. It may not matter though.
On the other hand, you could set idCliente as an identity field such that it also begins with 1000. This is "tied" to the table and, in my opinion, is easier to use. The number just get generated automatically.
So you might do something like:
Alter table dbo.MiCliente add idCliente INT IDENTITY(1000,1)
And then you can make it your primary key as well:
alter table dbo.MiCliente add constraint PK_MiCliente PRIMARY KEY(idCliente)

Answer 2

When I executed your query it simply gives following error:
Msg 11708, Level 16, State 1, Line 2
An invalid value was specified for argument 'START WITH' for the given data type.
It is clearly evident of the fact that you are using wrong data type tinyint while creating the sequence. Changing it to int should solve your problem. Here is the modified query. Hope this helps!
Create Sequence Conteo
AS int
START WITH 1000
INCREMENT BY 1
GO
I was able to create the sequence successfully after making this change. I'm on SQL Server 2012.