Foreign key #SQL

gistfile1.sql

Check If Primary Key exists:
IF EXISTS(SELECT * FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE  CONSTRAINT_TYPE = 'PRIMARY KEY'
            AND TABLE_NAME = 'SAT_Lands_Open_Source'
            AND TABLE_SCHEMA ='rlt')
            ALTER TABLE [rlt].[SAT_Lands_Open_Source] DROP CONSTRAINT [PK_Realty_Lands_Open_Source]

 SQL server will not let you truncate the table while the constraint exists, even if it's disabled. Drop the constraint and re-create it after truncating the table. Or just drop and re-create the tables, whichever is easier to do in your application.

IF EXISTS (SELECT *
  FROM sys.foreign_keys
   WHERE object_id = OBJECT_ID( N'FK_ETL_PACKAGE_ETL_LOADERS')
   AND parent_object_id = OBJECT_ID( N'[cfg].[ETL_PACKAGE]')
)
  ALTER TABLE [cfg] .[ETL_PACKAGE] DROP CONSTRAINT [FK_ETL_PACKAGE_ETL_LOADERS]
 
GO

truncate table [cfg]. [ETL_LOADERS]
truncate table [cfg]. [ETL_PACKAGE]

GO

--Add Foreign key back

COMMIT
BEGIN TRANSACTION
GO
ALTER TABLE cfg. ETL_LOADERS SET (LOCK_ESCALATION = TABLE )
GO
COMMIT
BEGIN TRANSACTION
GO
ALTER TABLE cfg. ETL_PACKAGE ADD CONSTRAINT
        FK_ETL_PACKAGE_ETL_LOADERS FOREIGN KEY
        (
        Loader_Code
        ) REFERENCES cfg. ETL_LOADERS
        (
        Loader_Code
        ) ON UPDATE  NO ACTION
        ON DELETE   NO ACTION
       
GO
ALTER TABLE cfg. ETL_PACKAGE SET (LOCK_ESCALATION = TABLE )
GO
COMMIT