status--是否启用 from user_constraints--[all_constraints|dba_constraints] where constraint_name='CHECK_TB_SUPPLIER_ID'; 8. 删除CHECK约束 8.1 语法 ALTERTABLE table_name DROPCONSTRAINT constraint_name; 8.2 示例 ALTERTABLE tb_supplier DROPCONSTRAINT check_tb_supplier_id;...
status--是否启用 from user_constraints--[all_constraints|dba_constraints] where constraint_name='CHECK_TB_SUPPLIER_ID'; 1. 2. 3. 4. 5. 6. 7. 8. 9. 8. 删除CHECK约束 8.1 语法 ALTER TABLE table_name DROP CONSTRAINT constraint_name; 1. 2. 8.2 演示样例 ALTER TABLE tb_supplier DROP CO...
Create Named CHECK Constraint It's a good practice to createnamed constraintsso that it is easier to alter and drop constraints. Here's an example to create a namedCHECKconstraint: -- create a named constraint named amountCK-- the constraint makes sure that amount is greater than 0CREATETABLE...
ALTERTABLEtable_nameENABLECONSTRAINTcheck_positive_buy_price;Code language:SQL (Structured Query Language)(sql) Restrictions of Oracle check constraint# Oracle check constraints are subject to the following restrictions: You can define check constraints for tables only, not views. The expression of the ...
oracle check 环境变量: set linesize 200 pagesize 10000 time on timing on col owner for a10 col segment_name for a30 col object_name for a30 alter session set nls_date_format='yyyymmdd hh24:mi:ss'; alter session set nls_language=american;...
query to find unique constraints on a table in oracle SQL> CREATE TABLE DEPT_MASTER ( dept_nr NUMBER UNIQUE, dept_name varchar2(100) NOT NULL, dept_status NUMBER(1,0) NOT NULL, created_at date ); Table created. SQL> select CONSTRAINT_NAME,INDEX_NAME,CONSTRAINT_TYPE from user_constraints...
Constraints have names. It is good practice to specify the names with a standard naming convention, but if they are not explicitly named, Oracle will generate names. 由上可知,每一个约束都有名称,最好的做法是在定义约束是显式的命名,如果没有显式命名,那么系统会提供一个名字。
我测试了一下,事实证明是可以的,Oracle的Check Constraints可以通过imp,使用indexfile来获得,并且可以通过手工执行脚本来加载。 以下是一个简单的测试过程。创建测试表: [oracle@oracle ~]$ sqlplus EYGLE/EYGLE SQL*Plus: Release 10.2.0.5.0 - Production on Tue Jul 13 23:48:35 2010 ...
12 rows in set (0.00 sec) 相关实现 1.新增代码文件 sql/sql_check_constraint.cc sql/dd/impl/system_views/check_constraints.cc sql/dd/impl/types/check_constraint_impl.cc 2.表达式定义及存储 InnoDB新增了一个数据词典表mysql.check_constraints用来存储所有的约束条件,表的定义在文件sql/dd/impl/tables...
oracle数据库 如何查询某个表的约束条件 使用下面语句从all_constraints视图中查看某表上的约束: SELECT constraint_name, table_name, r_owner, r_constraint_name...all_constraints WHERE table_name = 'table_name' and owner = 'owner_name'; 另一个视图ALL_CONS_COLUMNS也包括组成表上约束列的信息 3.4K...