So, we can easily find all the constraints on the table in Oracle using data dictionary views. We can then take whatever action like modify, disable, or drop, we want to take on these constraints. Constraints are enforcing data integrity rules in the Oracle database and we must be careful...
1.comment on table 2.comment on column 【constraint】 1.约束的种类 2.约束的4种状态 3.添加约束,删除约束,修改约束的状态,查看约束
drop table t1; drop table t2; drop view v; create table t1 as select * from all_objects where object_type in ('TABLE','VIEW'); alter table t1 modify object_type not null; alter table t1 add constraint t1_check_otype check (object_type in('TABLE','VIEW')); create table t2 as ...
oracle是对关键字的大小写不敏感，但是你取得是系统表user_constraints 里的数据，数据本身当然区分大小写了
Oracle views are used to simplify a complex query by hiding the entire internal table joins operations. Declarative primary key, unique key and foreign key constraints can now be defined against views as given below. The constraints are not validated so they must be defined with the DISABLE NOVA...
In Oracle, a unique constraint can not contain more than 32 columns. Unique constraints can be defined in either a CREATE TABLE statement or an ALTER TABLE statement. These are the ways to create the constraint : CREATE TABLE table_name ...
TABLE_NAME The name of the table. CONSTRAINT_TYPE The type of constraint. The value can beUNIQUE,PRIMARY KEY,FOREIGN KEYorCHECK. This is aCHAR(notENUM) column. TheUNIQUEandPRIMARY KEYinformation is about the same as what you get from theKey_namecolumn in the output fromSHOW INDEXwhen the...
Create unique Contraint - Using a CREATE TABLE statement The syntax for creating a unique constraint using a CREATE TABLE statement in Oracle is: CREATE TABLE table_name ( column1 datatype [ NULL | NOT NULL ], column2 datatype [ NULL | NOT NULL ], ... CONSTRAINT constraint_name UNIQUE ...
Oracle Database Gateway for DRDAのALL_CONSTRAINTSデータ・ディクショナリ。 ALL_CONSTRAINTSビューには、アクセス可能な表の制約定義が含まれます。 列名説明 OWNER 制約定義の所有者 CONSTRAINT_NAME 制約定義の名前 CONSTRAINT_TYPE 制約定義のタイプ TABLE_NAME 制約定義のある表の名前 SEARCH_CONDITION...
该视图仅适用于 OceanBase 数据库 Oracle 模式。 字段说明 字段名称类型是否可以为 NULL描述 OWNER VARCHAR2(128) NO 约束的拥有者 CONSTRAINT_NAME VARCHAR2(128) NO 约束名字 CONSTRAINT_TYPE VARCHAR2(1) NO 索引类型,目前只支持 NORMAL类型 TABLE_NAME VARCHAR2(128) NO 约束所在的表的名字 SEARCH_CONDITION ...