Answers for "sql alter table add foreign key"

SQL

drop foreign key

ALTER TABLE table_name
DROP CONSTRAINT fk_name;

Posted by: Guest on June-04-2020

Source

mysql add foreign key

-- On Create
CREATE TABLE tableName (
    ID INT,
    SomeEntityID INT,
    PRIMARY KEY (ID),
    FOREIGN KEY (SomeEntityID)
        REFERENCES SomeEntityTable(ID)
        ON DELETE CASCADE
);

-- On Alter, if the column already exists but has no FK
ALTER TABLE
  tableName
ADD
  FOREIGN KEY (SomeEntityID) REFERENCES SomeEntityTable(ID) ON DELETE CASCADE;
  
 -- Add FK with a specific name
 -- On Alter, if the column already exists but has no FK
ALTER TABLE
  tableName
ADD CONSTRAINT fk_name
  FOREIGN KEY (SomeEntityID) REFERENCES SomeEntityTable(ID) ON DELETE CASCADE;

Posted by: Guest on April-27-2020

alter table add key sql server

ALTER TABLE Persons
ADD CONSTRAINT PK_Person PRIMARY KEY (ID,LastName);

Posted by: Guest on January-26-2021

-1

add new column in sql with foreign key

ALTER TABLE `fb_banners`
ADD `city_id` BIGINT(20) UNSIGNED NULL DEFAULT NULL AFTER `BannerID`,
ADD INDEX `Foreign_city_id_banners` (`city_id`) USING BTREE,
ADD CONSTRAINT `Foreign_city_id_banners` FOREIGN KEY (`city_id`) REFERENCES `foodsafari`.`fb_cities` (`id`) ON UPDATE CASCADE ON DELETE CASCADE;

Posted by: Guest on November-22-2020

Code answers related to "sql alter table add foreign key"

Code answers related to "SQL"

Browse Popular Code Answers by Language

Python

Javascript

Whatever

Shell/Bash

CSS

Html

PHP

SQL

Java

Answers for "sql alter table add foreign key"

Code answers related to "sql alter table add foreign key"

Code answers related to "SQL"

Browse Popular Code Answers by Language

Popular Programming Languages

Advertisements

Company

Compilers

Help

Connect with us