sql - powerapps - Agregar clave principal a la tabla existente

powerapps ejemplos

Question

Tengo una tabla existente llamada Persion . En esta tabla tengo 5 columnas:

• persionId
• Pname
• PMid
• Pdescription
• Pamt

Cuando creé esta tabla, configuré PersionId y Pname como la clave principal .

Ahora quiero incluir una columna más en la clave principal - PMID. ¿Cómo puedo escribir una declaración ALTER para hacer esto? (Ya tengo 1000 registros en la tabla)

Answer 1

Creo que algo como esto debería funcionar

-- drop current primary key constraint
ALTER TABLE dbo.persion
DROP CONSTRAINT PK_persionId;
GO
-- add new auto incremented field
ALTER TABLE dbo.persion
ADD pmid BIGINT IDENTITY;
GO
-- create new primary key constraint
ALTER TABLE dbo.persion
ADD CONSTRAINT PK_persionId PRIMARY KEY NONCLUSTERED (pmid, persionId);
GO

Answer 2

Intenta usar este código:

ALTER TABLE `table name`
CHANGE COLUMN `column name` `column name` datatype NOT NULL,
ADD PRIMARY KEY (`column name`) ;

Answer 3

La restricción PRIMARY KEY identifica de forma única cada registro en una tabla de base de datos. Las claves primarias deben contener valores UNIQUE y la columna no puede contener valores NULL.

 -- DROP current primary key
ALTER TABLE tblPersons DROP CONSTRAINT <constraint_name>
Example:
ALTER TABLE tblPersons
DROP CONSTRAINT P_Id;
-- ALTER TABLE tblpersion
ALTER TABLE tblpersion add primary key (P_Id,LastName)

Answer 4

Nigromancia
Solo en caso de que alguien tenga un esquema tan bueno para trabajar como yo ...
Aquí es cómo hacerlo correctamente:

En este ejemplo, el nombre de la tabla es dbo.T_SYS_Language_Forms, y el nombre de la columna es LANG_UID

-- First, chech if the table exists...
IF 0 < (
SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = ''BASE TABLE''
AND TABLE_SCHEMA = ''dbo''
AND TABLE_NAME = ''T_SYS_Language_Forms''
)
BEGIN
-- Check for NULL values in the primary-key column
IF 0 = (SELECT COUNT(*) FROM T_SYS_Language_Forms WHERE LANG_UID IS NULL)
BEGIN
ALTER TABLE T_SYS_Language_Forms ALTER COLUMN LANG_UID uniqueidentifier NOT NULL
-- No, don''t drop, FK references might already exist...
-- Drop PK if exists (it is very possible it does not have the name you think it has...)
-- ALTER TABLE T_SYS_Language_Forms DROP CONSTRAINT pk_constraint_name
--DECLARE @pkDropCommand nvarchar(1000)
--SET @pkDropCommand = N''ALTER TABLE T_SYS_Language_Forms DROP CONSTRAINT '' + QUOTENAME((SELECT CONSTRAINT_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS
--WHERE CONSTRAINT_TYPE = ''PRIMARY KEY''
--AND TABLE_SCHEMA = ''dbo''
--AND TABLE_NAME = ''T_SYS_Language_Forms''
----AND CONSTRAINT_NAME = ''PK_T_SYS_Language_Forms''
--))
---- PRINT @pkDropCommand
--EXECUTE(@pkDropCommand)
-- Instead do
-- EXEC sp_rename ''dbo.T_SYS_Language_Forms.PK_T_SYS_Language_Forms1234565'', ''PK_T_SYS_Language_Forms'';
-- Check if they keys are unique (it is very possible they might not be)
IF 1 >= (SELECT TOP 1 COUNT(*) AS cnt FROM T_SYS_Language_Forms GROUP BY LANG_UID ORDER BY cnt DESC)
BEGIN
-- If no Primary key for this table
IF 0 =
(
SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS
WHERE CONSTRAINT_TYPE = ''PRIMARY KEY''
AND TABLE_SCHEMA = ''dbo''
AND TABLE_NAME = ''T_SYS_Language_Forms''
-- AND CONSTRAINT_NAME = ''PK_T_SYS_Language_Forms''
)
ALTER TABLE T_SYS_Language_Forms ADD CONSTRAINT PK_T_SYS_Language_Forms PRIMARY KEY CLUSTERED (LANG_UID ASC)
;
END -- End uniqueness check
ELSE
PRINT ''FSCK, this column has duplicate keys, and can thus not be changed to primary key...''
END -- End NULL check
ELSE
PRINT ''FSCK, need to figure out how to update NULL value(s)...''
END

Answer 5

Por favor, intente esto-

ALTER TABLE TABLE_NAME DROP INDEX `PRIMARY`, ADD PRIMARY KEY (COLUMN1, COLUMN2,..);

Answer 6

Si agrega restricción de clave principal

ALTER TABLE <TABLE NAME> ADD CONSTRAINT <CONSTRAINT NAME> PRIMARY KEY <COLUMNNAME>

por ejemplo:

ALTER TABLE DEPT ADD CONSTRAINT PK_DEPT PRIMARY KEY (DEPTNO)

Answer 7

eliminar la restricción y recrearla

alter table Persion drop CONSTRAINT <constraint_name>
alter table Persion add primary key (persionId,Pname,PMID)

editar:

puedes encontrar el nombre de la restricción usando la consulta a continuación:

select OBJECT_NAME(OBJECT_ID) AS NameofConstraint
FROM sys.objects
where OBJECT_NAME(parent_object_id)=''Persion''
and type_desc LIKE ''%CONSTRAINT''

Answer 8

-- create new primary key constraint
ALTER TABLE dbo.persion
ADD CONSTRAINT PK_persionId PRIMARY KEY NONCLUSTERED (pmid, persionId);

es una mejor solución porque tienes control sobre el nombre de la clave primaria.

Es mejor que solo usar

ALTER TABLE Persion ADD PRIMARY KEY(persionId,Pname,PMID)

que genera nombres aleatorios y puede causar problemas al crear scripts o al comparar bases de datos

Answer 9

ALTER TABLE TABLE_NAME ADD PRIMARY KEY(`persionId`,`Pname`,`PMID`)