1.主键约束:列被约束为(非空、不重复) 格式:alter table 表格名称 add constraint 约束名称 primary key (列名) 例子:alter table emp add constraint ppp primary key (id); 2.外键约束:列被约束为引用其他表的主键 格式:alter table 表名 add constraint 约束名称 foreign key (列名) references 被引用的表...
oracle add constraint用法 Oracle中使用ADD CONSTRAINT语句来添加约束。具体用法如下: 1.添加主键约束: ALTER TABLE table_name ADD CONSTRAINT pk_constraint PRIMARY KEY (column1, column2, ...); 2.添加唯一约束: ALTER TABLE table_name ADD CONSTRAINT unique_constraint UNIQUE (column1, column2, ...);...
Oracle数据库学习笔记_oracle之addconstraint⽅法添加约束add constraint ⽅法在已经存在的列名添加约束，语法格式如下：alter table 表名 add constraint 约束名称约束类型(列名)具体⽤法如下：1.主键约束：列被约束为（⾮空、不重复）格式：alter table 表格名称 add constraint 约束名称 primary key ...
Oracle Primavera Cloud Help Privacy and Accessibility Get Started with Oracle Primavera Cloud The Projects List The Project Home Screen Overview Work Plan Constraints Constraints Overview View Constraints for Your Tasks Deliver a Task Constraint Discuss a Constraint Add a Constraint Edit a Constraint Delet...
oracle主键添加语句通常紧跟在建表语句之后,也可以直接嵌在列声明里创建,oracle创建主键时会自动在该列上创建索引。常见方法大概有以下5种: 方法一、使用add constraint 方法添加主键约束 alter table 表名 add constraint 主键名 primary key (列名1,列名2,...) ...
(again)]– which means that adding a primary key may also result in a tablescan for every column in the constraint/index before the index is created – but in that case you can’t see the SQL that checks each column, you have to infer the check from the number of tablescans and ...
Add constraint to ensure that value from one column is bigger than that from another : Check « Table « Oracle PL/SQL Tutorial
1.语法:ALTER TABLE 表名 ADD CONSTRAINT 主键名 PRIMARY KEY 表名(主键字段); 3.添加外键 1.语法:ALTER TABLE 表名 ADD CONNSTRAINT 外键名 FOREIGN KEY(外键字段) REFERENCES 关联表名(关联字段); 4.插入单(多)条数据记录(和SQL Server相同,但是不能用select多列添加数据) ...
ORA-00001: unique constraint (SQL_BEPRLXNSYQBEXHORZZOSBAVTS.T23_PK) violated ORA-06512: at "SYS.DBMS_SQL", line 1721 More Details: https://docs.oracle.com/error-help/db/ora-00001 Statement 12 create table t23i (EMP_NAME varchar2(20), EMP_POS varchar2(20), SALARY number, GENDER...
DEFERRED: only check while you commit transaction, if this deferred constraint is violated, undo this transaction. NO DEFERRED: check immediate while every sql statement, if this non-deferred constranit is violated , only undo current statement. ...