Constraints on a table in Oracle can be found using the below views user_constraints: It provides information about constraints owned by the current user. all_constraints:shows information about constraints accessible to the current user, including those owned by other users. dba_constraints: provides...
iskey from user_tab_cols t, user_col_comments c, (select m.column_name from user_constraints s, usercons_columns m where lower(m.table_name)='表名' and m.table_name=stable_name and m.constraintname=s.constraintname ands.constraint_type'P') m where lower(t._name)='表...
SELECT DBMS_METADATA.GET_DEPENDENT_DDL ('INDEX', TABLE_NAME, TABLE_OWNER) FROM (SELECT table_name, table_owner FROM Dba_indexes WHERE table_owner = UPPER (TRIM('&TABLE_OWNER')) AND table_name = UPPER (TRIM('&TABLE_NAME')) AND index_name NOT IN (SELECT constraint_name FROM DBA_CONS...
from user_constraints c,user_cons_columns cc where c.owner = upper('&table_owner') and c.table_name = upper('&table_name') and c.owner = cc.owner and c.constraint_name = cc.constraint_name order by cc.position; 8 存储函数和过程 1、 查看函数和过程的状态 SQL>select object_name,sta...
我们可以发现利用Drop table cascade constraints可以以刪除关联table t的constraint來达成你drop table t的目的,原來属于t1的foreign key constraint已经跟随着被删除掉了,但是,储存在table t1的资料可不会被删除,也就是说Drop table cascade constraints 是不影响到存储于objec里的row data。
SQL> alter table users drop column PID cascade constraints; SQL> alter table users rename column newColumn to PID; SQL> commit; SQL> desc users; 名称 是否为空? 类型 --- --- --- NAME NOT NULL VARCHAR2(10) AGE NUMBER PID VARCHAR2(20) SQL> select * from users; NAME AGE PID ...
Tests whether the given Column appears in any ColumnConstraint on its owning table of given constraint types. Parameters: col - the column to tests (must be parented by a table) constraintTypes - the types of ColumnConstraint to search for. Returns: true if the column appears in any of ...
Sequences exist independently of any particular table, so more than one table can use the same sequence number. Consider what might happen if you didn’t use Oracle sequences. You might store the last sequence number used in a column in a table. A user who wanted to get the next ...
"No valid primary key found for source table [<TableOwner>].[<TableName>]" For information about requirements for primary keys, see the section "Unique Indexes and Constraints" in the topicDesign Considerations and Limitations for Oracle Publishers. ...
From table_name versions between timestamp minvalue and maxvalue; 1. 2. 通过以上查询,根据versions_xid可以清晰地区分不同事务在不同时间对数据所作的更改。 由于这个查询需要从Undo中获取前镜像信息,如果Undo中的信息被覆盖,则以上查询将会失败。