MySQL primary key [closed]

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MySQL primary key [closed]

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#1 by (1 votes)
#2 by (0 votes)
#3 by (-1 votes)

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I want to do that when inserting a data block in a database, but that my Primary Key is the same for that data block, and it increases when it is finished inserting

Any ideas?

mysql

asked by J. Torres 15.10.2016 в 01:12

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3 answers

Embed the Internet explorer browser in a form using c #? [closed] error in try catch

score 1 · Answer 1

The primary keys are unique , therefore, unrepeatable. I would recommend you use an index .

One way you could be this:

Create a table to group the data, for example:

CREATE TABLE 'datos_grupos' (
  'idGrupo' int(11) NOT NULL,
  'nombre' tinytext COLLATE latin1_general_ci NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1 COLLATE=latin1_general_ci;

ALTER TABLE 'datos_grupos'
  ADD PRIMARY KEY ('id');

ALTER TABLE 'datos_grupos'
  MODIFY 'id' int(11) NOT NULL AUTO_INCREMENT;

Note : This table has an incremental auto primary key.

Create a table for the records to be grouped

CREATE TABLE 'datos' (
  'id' int(11) NOT NULL,
  'dato' text COLLATE latin1_general_ci NOT NULL,
  'idGrupo' int(11) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1 COLLATE=latin1_general_ci;

ALTER TABLE 'datos'
  ADD PRIMARY KEY ('id'),
  ADD KEY 'idGrupo' ('idGrupo');

ALTER TABLE 'datos'
  ADD PRIMARY KEY ('id');

Note : This table has an incremental auto primary key. Also an index type key in which the reference index to the first table must be saved

With these 2 tables, before inserting the first group of data, you should create a group and each data indicate the group. Example:

# Creamos el primer grupo
INSERT INTO 'datos_grupos' ('nombre') VALUES ('grupo 1');
set @idGrupo = last_insert_id();

# Por cada dato
INSERT INTO 'datos' ('nombre', 'idGrupo') VALUES ('dato1', @idGrupo);

Finally, if you want to obtain all the data related to a group, one option would be:

SELECT * FROM 'datos' WHERE idGrupo = 1

score 0 · Answer 2

I would like to know in which database engine you work.

Because some of them have tools like graphic and then generate the code.

But just in case:

CREATE TABLE PROFESOR(
     ID          INT          NOT NULL ***IDENTITY*** PRIMARY KEY,
     NOMBRE      VARCHAR(100) NOT NULL,
     APELLIDO    VARCHAR(100) NOT NULL,
     EDAD        INT          NOT NULL
)

INSERT INTO PROFESOR(NOMBRE, APELLIDO, EDAD) VALUES
     (‘Miguel’,’Cervantes’,23),
     (‘Augusto’,’Munch’,32),
     (‘Minerva’,’Fredson’,29);

Extracted from: link

score -1 · Answer 3

To be able to do what you want you have to create a variable, this has to contain the value of your Primary Key.

Here is an example:

CREATE TABLE Tabla_01 (
    id INT NOT NULL,
    campo1 VARCHAR(100),
    campo2 varchar(100)
);

CREATE TABLE Tabla_02 (
    id INT NOT NULL,
    idT1 int NOT NULL,
    campo1 VARCHAR(100),
    campo2 varchar(100)
);


set @ident=1;

insert into Tabla_01 (id,campo1,campo2)
Values (@ident,'ValorCampo1','ValorCampo2');

insert into Tabla_02 (id,idT1,campo1,campo2)
values
(1,@ident,'ValorCampo1','ValorCampo2'),
(2,@ident,'ValorCampo1','ValorCampo2'),
(3,@ident,'ValorCampo1','ValorCampo2');

set @ident=@ident+1;

insert into Tabla_02 (id,idT1,campo1,campo2)
values
(1,@ident,'ValorCampo1','ValorCampo2'),
(2,@ident,'ValorCampo1','ValorCampo2'),
(3,@ident,'ValorCampo1','ValorCampo2');

You can see this example in SQL Fiddle .