How to delete oracle constraints

Method: 1. Use the "ALTER TABLE table name DROP CONSTRAINT constraint name;" statement to delete the primary key constraint; 2. Use the "Alter Table table Modify column type Null;" statement to delete the non-null constraint.

The operating environment of this tutorial: Windows 10 system, Oracle 11g version, Dell G3 computer.

How to delete oracle constraints

1. Delete primary key constraints:

Alter table 表名 drop 约束名

With named primary key:

Alter table one drop constraint pk_one;

No named primary key: Available Select * from user_constraints search The primary key name constraint_name in the table, and then use the found primary key name. For example: alter table student drop constraint SYS_C002715;

(When deleting component constraints, you must also delete the foreign key constraints that reference the primary key). For example:

alter table two drop constraint two_pk_id;

2. Delete non-empty constraints:

Syntax:

Alter Table 表 Modify 列 类型 Null;

For example:

Alter table one Modify name  null;

Recommended tutorial: "Oracle Video Tutorial"

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