ALTERTABLEtable_nameDISABLECONSTRAINTcheck_constraint_name;ALTERTABLEtable_nameENABLECONSTRAINTcheck_constraint_name;Code language:SQL (Structured Query Language)(sql) For example, to temporarily disable thecheck_positive_buy_priceconstraint, you use the following statement: ALTERTABLEtable_nameDISABLECONSTRAINT...
Example ALTER TABLE suppliers ADD CONSTRAINT check_supplier_name CHECK (supplier_name IN ('IBM', 'Microsoft', 'NVIDIA')); In this example, we've created a check constraint on the existing suppliers table called check_supplier_name. It ensures that the supplier_name field only contains the fo...
SQL> select CONSTRAINT_NAME,INDEX_NAME,CONSTRAINT_TYPE,table_name from user_constraints where CONSTRAINT_NAME='PK_DEPT'; How to check the primary key in the table SQL> select CONSTRAINT_NAME C_NAME,INDEX_NAME,CONSTRAINT_TYPE from user_constraints where TABLE_NAME='EMP' and CONSTRAINT_TYPE='P...
1) 这对属性定义是否defer. Deferred: check on commit; immediate: check immediate. 2) If constraint is not deferrable,immediate is only choice. 3) For example: CREATE TABLE games (scores NUMBER, CONSTRAINT unq_num UNIQUE (scores) INITIALLY DEFERRED DEFERRABLE); insert into games values(1); ins...
1)这对属性定义是否defer. Deferred: check on commit; immediate: check immediate. 2)If constraint is not deferrable,immediate is only choice. 3) For example: 复制 CREATE TABLE games(scores NUMBER, CONSTRAINT unq_num UNIQUE (scores)INITIALLY DEFERRED DEFERRABLE);insert into games values(1);insert...
(sno number(5) constraint pk_t_pk4_sno primary key using index tablespace example, sname varchar2(20), idcard varchar2(18), createtime date ); 5、表级定义主键,自定义主键名称,并且指定索引使用的表空间 create table t_pk5 (sno number(5), ...
See this demo for a 10g check constraint example: Check Constraints with 10g Making constraints deferrable or enabling them with novalidate can be useful. However, if possible, ensure constraints are not deferrable and validated as this provides the CBO with additional information regarding the columns...
>>> Could not execute auto check for display colors using command /usr/bin/xdpyinfo. Check if the DISPLAY variable is set. Failed <<< Some requirement checks failed. You must fulfill these requirements before continuing with the installation,at which time they will be rechecked. Continue...
A check constraint is a Boolean expression that evaluates to either TRUE or FALSE. If the check constraint evaluates to FALSE, the SQL statement that caused the result returns an error. For example, a check constraint might require the minimum balance in a bank account to be over $100. If...
Example:做一个日志用来记录scott用户的一些操作: 首先在sysdba权限下建立日志表,序列,触发器: CREATE TABLE object_log( logid NUMBER CONSTRAINT pk_logid PRIMARY KEY, operatedate DATE NOT NULL, objecttype VARCHAR2(50) NOT NULL, objectowner VARCHAR2(50) NOT NULL );CREATE SEQUENCE obj_log_seq;CREAT...