answersLogoWhite

0

To alter foreign keys in Oracle, you can use the ALTER TABLE statement. To modify an existing foreign key constraint, you typically need to drop the existing constraint first using ALTER TABLE table_name DROP CONSTRAINT constraint_name, then add a new foreign key constraint with the desired modifications using ALTER TABLE table_name ADD CONSTRAINT constraint_name FOREIGN KEY (column_name) REFERENCES other_table (other_column). If you only need to disable or enable the constraint without altering it, you can use ALTER TABLE table_name DISABLE CONSTRAINT constraint_name or ENABLE CONSTRAINT.

User Avatar

AnswerBot

2mo ago

What else can I help you with?

Related Questions

When was Foreign Keys created?

Foreign Keys was created in 1985.


What are the components of oracle database?

DDL - Data Definition Language Create,Alter,Drop and Truncate are the components of oracle database.


What are some of the functions for the alter table command in Oracle?

Some of the functions for the alter table command in Oracle include renaming columns or rows, adding columns or rows and marking items as being read only.


How do you change the current Oracle schema?

Alter session set current_schema=my_new_schema;


How do you use foreign key in to oracle?

the foreign key referential between two tables.


Oracle Alter a column's varchar length I want to change a varchar30 to a varchar20. can please help me get the syntax for it?

ALTER TABLE table_name MODIFY (column_name VARCHAR2(20));


Have foreign keys null values?

Yes Foreign key can have null value.


How do foreign keys ofrelations relate to candidate keys?

Foreign keys and candidate keys serve distinct roles in relational databases. A candidate key is a set of one or more attributes that can uniquely identify a tuple within a relation, while a foreign key is an attribute or a set of attributes in one relation that refers to the primary key of another relation. Foreign keys establish relationships between tables, ensuring referential integrity, whereas candidate keys ensure that each row within a table can be uniquely identified. Thus, while foreign keys link tables, candidate keys define uniqueness within a table.


What are the basic components of a database?

Tables, Entities, Attributes, Primary Keys, and Foreign Keys


What is difference between alter and modify on oracle?

MODIFY is a clause used within an ALTER statement, such as ALTER TABLE, ALTER INDEX or ALTER MATERIALIZED VIEW, etc. That is, MODIFY isn't a command by itself. For example, you might change the length of a text column in a table with the following: ALTER TABLE employee MODIFY (email_address VARCHAR(132));


How many foreign keys can you have in one table?

one


What are the limitations of keys and taxonomic system?

Mutations in an organisms' DNA alter its physical appearance