{"id":209852,"date":"2022-08-20T15:01:58","date_gmt":"2022-08-20T07:01:58","guid":{"rendered":"https:\/\/www.keaglegz.com\/209852.html"},"modified":"2026-07-15T06:49:09","modified_gmt":"2026-07-14T22:49:09","slug":"oracle-%e7%ba%a6%e6%9d%9f%e6%b7%b1%e5%85%a5%e7%90%86%e8%a7%a3","status":"publish","type":"post","link":"https:\/\/www.dongwubaike.cn\/fanhao\/209852.html","title":{"rendered":"Oracle \u7ea6\u675f\u6df1\u5165\u7406\u89e3"},"content":{"rendered":"\n

\u4e00 \u7ea6\u675f\u7684\u5b9a\u4e49<\/p>\n

\u7ea6\u675f\u662f\u5f3a\u52a0\u5728\u8868\u4e0a\u7684\u89c4\u5219\u6216\u6761\u4ef6\u3002\u786e\u4fdd\u6570\u636e\u5e93\u6ee1\u8db3\u4e1a\u52a1\u89c4\u5219\u3002\u4fdd\u8bc1\u6570\u636e\u7684\u5b8c\u6574\u6027\u3002\u5f53\u5bf9\u8868\u8fdb\u884cDML\u6216DDL\u64cd\u4f5c\u65f6\uff0c\u5982\u679c\u6b64\u64cd\u4f5c\u4f1a\u9020\u6210\u8868\u4e2d\u7684\u6570\u636e\u8fdd\u53cd\u7ea6\u675f\u6761\u4ef6\u6216\u89c4\u5219\u7684\u8bdd\uff0c\u7cfb\u7edf\u5c31\u4f1a\u62d2\u7edd\u6267\u884c\u8fd9\u4e2a\u64cd\u4f5c\u3002\u7ea6\u675f\u53ef\u4ee5\u662f\u5217\u4e00\u7ea7\u522b\u7684 \u4e5f\u53ef\u4ee5\u662f\u8868\u7ea7\u522b\u7684\u3002\u5b9a\u4e49\u7ea6\u675f\u65f6\u6ca1\u6709\u7ed9\u51fa\u7ea6\u675f\u7684\u540d\u5b57\uff0cORACE\u7cfb\u7edf\u5c06\u4e3a\u8be5\u7ea6\u675f\u81ea\u52a8\u751f\u6210\u4e00\u4e2a\u540d\u5b57\uff0c\u5176\u683c\u5f0f\u4e3aSYS_Cn\uff0c\u5176\u4e2dn\u4e3a\u81ea\u7136\u6570(\u5f3a\u70c8\u5efa\u8bae\u5404\u4f4d\u5728\u521b\u5efa\u8868\u6216\u589e\u52a0\u7ea6\u675f\u65f6\uff0c\u7ed9\u7ea6\u675f\u5b9a\u4e49\u540d\u79f0\u3002)
\u5728Oracle\u4e2d\uff0c\u6570\u636e\u5b8c\u6574\u6027\u53ef\u4ee5\u4f7f\u7528\u7ea6\u675f\u3001\u89e6\u53d1\u5668\u3001\u5e94\u7528\u7a0b\u5e8f\uff08\u8fc7\u7a0b\u3001\u51fd\u6570\uff09\u4e09\u79cd\u65b9\u6cd5\u6765\u5b9e\u73b0\uff0c\u5728\u8fd9\u4e09\u79cd\u65b9\u6cd5\u4e2d\uff0c\u56e0\u4e3a\u7ea6\u675f\u6613\u4e8e\u7ef4\u62a4\uff0c\u5e76\u4e14\u5177\u6709\u6700\u597d\u7684\u6027\u80fd\uff0c\u6240\u4ee5\u4f5c\u4e3a\u7ef4\u62a4\u6570\u636e\u5b8c\u6574\u6027\u7684\u9996\u9009\u3002<\/p>\n

\u5217\u7ea7\u7ea6\u675f\uff1a
\u5217\u7ea7\u5b9a\u4e49\u662f\u5728\u5b9a\u4e49\u5217\u7684\u540c\u65f6\u5b9a\u4e49\u7ea6\u675f\uff1b
column [CONSTRAINT constraint_name] constraint_type
\u8868\u7ea7\u7ea6\u675f\uff1a
\u8868\u7ea7\u5b9a\u4e49\u662f\u6307\u5728\u5b9a\u4e49\u4e86\u6240\u6709\u5217\u540e\uff0c\u518d\u5b9a\u4e49\u7ea6\u675f\uff0c\u8fd9\u91cc\u9700\u8981\u6ce8\u610f\uff0cnot null\u7ea6\u675f\u53ea\u80fd\u5728\u5217\u7ea7\u4e0a\u5b9a\u4e49\uff1b
column ,…,
[CONSTRAINT constraint_name] constraint_type (column,…)<\/p>\n

\u4e8c \u7ea6\u675f\u529f\u80fd<\/p>\n

\u7ea6\u675f\u7684\u529f\u80fd\uff1a\u5b9e\u73b0\u4e00\u4e9b\u4e1a\u52a1\u89c4\u5219\uff0c\u9632\u6b62\u65e0\u6548\u7684\u5783\u573e\u6570\u636e\u8fdb\u5165\u6570\u636e\u5e93\uff0c\u7ef4\u62a4\u6570\u636e\u5e93\u7684\u5b8c\u6574\u6027(\u5b8c\u6574\u6027\u6307\u6b63\u786e\u6027\u4e0e\u4e00\u81f4\u6027)\u3002\u4ece\u800c\u4f7f\u6570\u636e\u5e93\u7684\u5f00\u53d1\u548c\u7ef4\u62a4\u90fd\u66f4\u52a0\u5bb9\u6613\u3002<\/p>\n

\u4e09 \u7ea6\u675f\u7684\u5206\u7c7b<\/p>\n

1 not null\uff08\u975e\u7a7a\uff09
\u5982\u679c\u5728\u5217\u4e0a\u5b9a\u4e49\u4e86not null\uff0c\u90a3\u4e48\u5f53\u63d2\u5165\u6570\u636e\u65f6\uff0c\u5fc5\u987b\u4e3a\u5217\u63d0\u4f9b\uff0c\u6570\u636e\u4e0d\u80fd\u4e3aNULL\u3002\u7ea6\u675f\u53ea\u80fd\u5728\u5217\u7ea7\u5b9a\u4e49\uff0c\u4e0d\u80fd\u5728\u8868\u7ea7\u5b9a\u4e49\u3002<\/p>\n

2 unique\uff08\u552f\u4e00\uff09
\u5f53\u5b9a\u4e49\u4e86\u552f\u4e00\u7ea6\u675f\u540e\uff0c\u8be5\u5217\u503c\u662f\u4e0d\u80fd\u91cd\u590d\u7684\uff0c\u4f46\u662f\u53ef\u4ee5\u4e3anull\u3002
3 primary key\uff08\u4e3b\u952e\uff09
\u7528\u4e8e\u552f\u4e00\u7684\u6807\u8bc6\u8868\u884c\u7684\u6570\u636e\uff0c\u5f53\u5b9a\u4e49\u4e3b\u952e\u7ea6\u675f\u540e\uff0c\u8be5\u5217\u4e0d\u4f46\u4e0d\u80fd\u91cd\u590d\u800c\u4e14\u4e0d\u80fd\u4e3aNULL\u3002\u4e00\u5f20\u8868\u6700\u591a\u53ea\u80fd\u6709\u4e00\u4e2a\u4e3b\u952e\uff0c\u4f46\u662f\u53ef\u4ee5\u7531\u591a\u4e2aunique\u7ea6\u675f\u3002
\u521b\u5efa\u4e3b\u952e\u6216\u552f\u4e00\u7ea6\u675f\u540e\uff0cORACLE\u4f1a\u81ea\u52a8\u521b\u5efa\u4e00\u4e2a\u4e0e\u7ea6\u675f\u540c\u540d\u7684\u7d22\u5f15\uff08UNIQUENES\u4e3aUNIQUE\u552f\u4e00\u7d22\u5f15\uff09\u3002\u9700\u8981\u6ce8\u610f\u7684\u662f\uff1a\u6bcf\u4e2a\u8868\u53ea\u80fd\u6709\u4e14\u6709\u4e00\u4e2a\u4e3b\u952e\u7ea6\u675f\u3002
4 foreign key\uff08\u5916\u952e\uff09
\u7528\u4e8e\u5b9a\u4e49\u4e3b\u8868\u548c\u4ece\u8868\u4e4b\u95f4\u7684\u5173\u7cfb\uff0c\u5916\u952e\u7ea6\u675f\u8981\u5b9a\u4e49\u5728\u4ece\u8868\u4e0a\uff0c\u4e3b\u8981\u5219\u5fc5\u987b\u5177\u6709\u4e3b\u952e\u7ea6\u675f\u6216\u662funique\u7ea6\u675f\uff0c\u5f53\u5b9a\u4e49\u5916\u952e\u7ea6\u675f\u540e\uff0c\u8981\u6c42\u5916\u952e\u5217\u6570\u636e\u5fc5\u987b\u5728\u4e3b\u8868\u7684\u4e3b\u952e\u5217\u5b58\u5728\u6216\u662f\u4e3aNULL\u3002
\u7528\u6765\u7ef4\u62a4\u4ece\u8868\uff08Child Table\uff09\u548c\u4e3b\u8868\uff08Parent Table\uff09\u4e4b\u95f4\u7684\u5f15\u7528\u5b8c\u6574\u6027. \u5916\u952e\u7ea6\u675f\u662f\u4e2a\u6709\u4e89\u8bae\u6027\u7684\u7ea6\u675f\uff0c\u5b83\u4e00\u65b9\u9762\u80fd\u591f\u7ef4\u62a4\u6570\u636e\u5e93\u7684\u6570\u636e\u4e00\u81f4\u6027\uff0c\u6570\u636e\u7684\u5b8c\u6574\u6027\u3002\u9632\u6b62\u9519\u8bef\u7684\u5783\u573e\u6570\u636e\u5165\u5e93\uff1b \u53e6\u5916\u4e00\u65b9\u9762\u5b83\u4f1a\u589e\u52a0\u8868\u63d2\u5165\u3001\u66f4\u65b0\u7b49SQL\u6027\u80fd\u7684\u989d\u5916\u5f00\u9500\uff0c\u4e0d\u5c11\u7cfb\u7edf\u91cc\u9762\u901a\u8fc7\u4e1a\u52a1\u903b\u8f91\u63a7\u5236\u6765\u53d6\u6d88\u5916\u952e\u7ea6\u675f\u3002\u4f8b\u5982\u5728\u6570\u636e\u4ed3\u5e93\u4e2d\uff0c\u5c31\u63a8\u8350\u7981\u7528\u5916\u952e\u7ea6\u675f\u3002
5 check
\u7528\u4e8e\u5f3a\u5236\u884c\u6570\u636e\u5fc5\u987b\u6ee1\u8db3\u7684\u6761\u4ef6\uff0c\u5047\u5b9a\u5728sal\u5217\u4e0a\u5b9a\u4e49\u4e86check\u7ea6\u675f\uff0c\u5e76\u8981\u6c42sal\u5217\u503c\u57281000\uff5e2000\u4e4b\u95f4\uff0c\u5982\u679c\u4e0d\u57281000\uff5e2000\u4e4b\u95f4\u5c31\u4f1a\u63d0\u793a\u51fa\u9519\u3002<\/p>\n

\u56db \u7ea6\u675f\u547d\u4ee4\u89c4\u8303<\/p>\n

\u7ea6\u675f\u540d\u79f0\u5efa\u8bae\u81ea\u5df1\u5b9a\u4e49\u4e00\u5957\u547d\u540d\u89c4\u5219\uff0c\u5426\u5219\u4f7f\u7528\u7cfb\u7edf\u751f\u6210\u7684\u7ea6\u675f\u540d\uff0c\u5f88\u96be\u80fd\u628a\u5b83\u548c\u5bf9\u5e94\u7684\u8868\u3001\u5b57\u6bb5\u8054\u7cfb\u8d77\u6765\u3002
\u3000\u3000\u3000\u3000\u975e\u7a7a\u7ea6\u675f \u3000\u3000\u3000\u3000NN\u8868\u540d\u5217\u540d
\u3000\u3000\u3000\u3000\u552f\u4e00\u7ea6\u675f \u3000\u3000\u3000\u3000UK\u8868\u540d\u5217\u540d
\u3000\u3000\u3000\u3000\u4e3b\u952e\u7ea6\u675f \u3000\u3000\u3000\u3000PK\u8868\u540d
\u3000\u3000\u3000\u3000\u5916\u952e\u7ea6\u675f \u3000\u3000\u3000\u3000FK\u8868\u540d\u5217\u540d
\u3000\u3000\u3000\u3000\u6761\u4ef6\u7ea6\u675f \u3000\u3000\u3000\u3000CK\u8868\u540d\u5217\u540d
\u3000\u3000\u3000\u3000\u9ed8\u8ba4\u7ea6\u675f \u3000\u3000\u3000\u3000DF\u8868\u540d\u5217\u540d
\u5982\u679c\u7ea6\u675f\u540d\u79f0\u8d85\u8fc732\u4f4d\u957f\u5ea6\uff0c\u5efa\u8bae\u5e94\u8be5\u7f29\u5199\u8868\u540d\uff0c\u800c\u4e0d\u5e94\u7528NN\u8868\u540d\u6570\u5b57\u3002\u4e0d\u8fc7\u5177\u4f53\u89c6\u60c5\u51b5\u800c\u5b9a\uff0c\u5f88\u591a\u65f6\u5019 DF\u8868\u540d_\u5217\u540d \u8fd9\u6837\u547d\u540d\uff0c\u5f80\u5f80\u8d85\u51fa\u4e8632\u5b57\u7b26\u3002\u6240\u4ee5\u6709\u65f6\u5019\u9700\u8981\u7f29\u5199\u8868\u9762\u6216\u662f\u91c7\u7528\u5176\u5b83\u89c4\u5219\u3002<\/p>\n

\u4e94 \u521b\u5efa\u7ea6\u675f
1 not null\uff08\u975e\u7a7a\uff09
\u521b\u5efa
SQL> create table t1(id number,name varchar2(20) constraint nn_t1_id not null);<\/p>\n

Table created.
SQL> col CONSTRAINT_NAME format A50
SQL> col OWNER format A20
SQL> select constraint_name,constraint_type,owner from user_constraints;<\/p>\n

CONSTRAINT_NAME C OWNER<\/p>\n

SYS_C009047 V SCOTT
FK_DEPTNO R SCOTT
SYS_C009046 C SCOTT
NN_T1_ID C SCOTT
PK_DEPT P SCOTT
PK_EMP P SCOTT<\/p>\n

6 rows selected.
\u4fee\u6539
SQL> drop table t1 purge;<\/p>\n

Table dropped.<\/p>\n

SQL> create table t1(id number,name varchar2(20));<\/p>\n

Table created.<\/p>\n

SQL> alter table t1 modify id constraint nn_t1_id not null;<\/p>\n

Table altered.<\/p>\n

SQL> select constraint_name,constraint_type,owner from user_constraints;<\/p>\n

CONSTRAINT_NAME C OWNER<\/p>\n

FK_DEPTNO R SCOTT
SYS_C009046 C SCOTT
NN_T1_ID C SCOTT
PK_DEPT P SCOTT
PK_EMP P SCOTT
SYS_C009047 V SCOTT
2 unique\uff08\u552f\u4e00\uff09
\u521b\u5efa
SQL> drop table t1 purge;<\/p>\n

Table dropped.<\/p>\n

SQL> create table t1(id number,qq number,constraint un_t1_qq unique(qq));<\/p>\n

Table created.
\u4fee\u6539
SQL> drop table t1 purge;<\/p>\n

Table dropped.<\/p>\n

SQL> create table t1(id number,qq number);<\/p>\n

Table created.
SQL> alter table t1 add constraint un_t1_qq unique(qq);<\/p>\n

Table altered.
3 primary key\uff08\u4e3b\u952e\uff09
\u521b\u5efa
SQL> drop table t1 purge;<\/p>\n

Table dropped.<\/p>\n

SQL> create table t1(id number,qq number,constraint pk_t1_id primary key(id));<\/p>\n

Table created.
\u4fee\u6539
SQL> drop table t1 purge;<\/p>\n

Table dropped.
SQL> create table t1(id number,qq number);<\/p>\n

Table created.<\/p>\n

SQL> alter table t1 add constraint pk_t1_id primary key(id);<\/p>\n

Table altered.
4 foreign key\uff08\u5916\u952e\uff09
\u521b\u5efa
SQL> create table t2(id number,cc number,constraint fk_t2_id foreign key(id) references t1(id));<\/p>\n

Table created.
\u4fee\u6539
SQL> drop table t2 purge
 2 ;<\/p>\n

Table dropped.<\/p>\n

SQL> create table t2(id number,cc number);<\/p>\n

Table created.<\/p>\n

SQL> alter table t2 add constraint pk_t2_id foreign key(id) references t1(id);<\/p>\n

Table altered.
\u5f53\u5b9a\u4e49\u4e86\u5916\u90e8\u952e\u7ea6\u675f\u4e4b\u540e\uff0c\u8981\u6c42\u5916\u90e8\u952e\u5217\u7684\u6570\u636e\u5fc5\u987b\u5728\u4e3b\u8868\u7684\u4e3b\u952e\u5217\uff08\u6216\u60df\u4e00\u5217\uff09\u4e2d\u5b58\u5728\uff0c\u6216\u8005\u4e3aNULL,FOREING KEY\u7ea6\u675f\u65e2\u53ef\u4ee5\u5728\u5217\u7ea7\u5b9a\u4e49\uff0c\u4e5f\u53ef\u4ee5\u5728\u8868\u7ea7\u5b9a\u4e49\u3002<\/p>\n

\u5173\u952e\u5b57\u8bf4\u660e\uff1a
(1) FOREING KEY:\u8be5\u9009\u9879\u7528\u4e8e\u6307\u5b9a\u5728\u8868\u7ea7\u5b9a\u4e49\u5916\u90e8\u952e\u7ea6\u675f\u3002\u5f53\u5728\u8868\u7ea7\u5b9a\u4e49\u5916\u90e8\u952e\u7ea6\u675f\u65f6\u5fc5\u987b\u6307\u5b9a\u8be5\u9009\u9879\uff0c\u5728\u5217\u7ea7\u5b9a\u4e49\u5916\u90e8\u952e\u7ea6\u675f\u4e0d\u9700\u8981\u6307\u5b9a\u8be5\u9009\u9879
(2) REFERENCES:\u8be5\u9009\u9879\u7528\u4e8e\u6307\u5b9a\u4e3b\u8868\u540d\u53ca\u5176\u4e3b\u952e\u5217\u3002\u5f53\u5b9a\u4e49\u5916\u90e8\u952e\u7ea6\u675f\u65f6\uff0c\u8be5\u9009\u9879\u5fc5\u987b\u6307\u5b9a.\u3002
(3) ON DELETE CASCAED:\u8be5\u9009\u9879\u7528\u4e8e\u6307\u5b9a\u7ea7\u8054\u5220\u9664\u9009\u9879\u3002\u5982\u679c\u5728\u5b9a\u4e49\u5916\u90e8\u952e\u7ea6\u675f\u65f6\u6307\u5b9a\u4e86\u8be5\u9009\u9879\uff0c\u90a3\u4e48\u5f53\u5220\u9664\u4e3b\u8868\u6570\u636e\u65f6\u4f1a\u7ea7\u8054\u5220\u9664\u4ece\u8868\u7684\u76f8\u5173\u6570\u636e\u3002
(4) ON DELECT SET NULL:\u8be5\u9009\u9879\u7528\u4e8e\u6307\u5b9a\u8f6c\u6362\u76f8\u5173\u7684\u5916\u90e8\u952e\u503c\u4e3aNULL\uff0c\u5982\u679c\u5728\u5b9a\u4e49\u5916\u90e8\u952e\u7ea6\u675f\u65f6\u6307\u5b9a\u4e86\u8be5\u9009\u9879\uff0c\u90a3\u4e48\u5f53\u5220\u9664\u4e3b\u8868\u6570\u636e\u65f6\u4f1a\u5c06\u4ece\u8868\u5916\u90e8\u952e\u5217\u7684\u6570\u636e\u8bbe\u7f6e\u4e3aNULL\u3002
5 check\uff08\u68c0\u67e5\u6027\u7ea6\u675f\uff09
\u521b\u5efa
SQL> create table t3(id number,sal number,constraint ck_t3_sal check(sal between 5000 and 50000));<\/p>\n

Table created.
\u4fee\u6539
SQL> drop table t3 purge;<\/p>\n

Table dropped.<\/p>\n

SQL> create table t3(id number,sal number);
\u516d \u7ef4\u62a4\u7ea6\u675f<\/p>\n

1 \u589e\u52a0\u7ea6\u675f
\uff081\uff09 \u5982\u679c\u589e\u52a0UNIQUE\u3001PRIMARY KEY\u3001FOREIGN KEY \u548cCKECK \u5fc5\u987b\u4f7f\u7528ALTER TABLE\u8bed\u53e5\u7684ADD\u5b50\u53e5;
\uff082\uff09 \u5982\u679c\u589e\u52a0NOT NULL\u7ea6\u675f\uff0c\u90a3\u4e48\u5fc5\u987b\u4f7f\u7528ALTER TABLE\u8bed\u53e5\u7684MODIFY\u5b50\u53e5\uff0c\u5982\uff1a
ALTER TABLE table_name ADD [CONSTRAINT constraint_name]
constraint_type (column,…)
ALTER TABLE table_name MODIFY column
[CONSTRAINT constraint_name] NOT NULL;<\/p>\n

2 \u4fee\u6539\u7ea6\u675f\u540d
\u5728\u540c\u4e00\u4e2a\u65b9\u6848\u4e2d\uff0c\u7ea6\u675f\u540d\u5fc5\u987b\u60df\u4e00,\u5e76\u4e14\u7ea6\u675f\u540d\u4e5f\u4e0d\u80fd\u4e0e\u5176\u4ed6\u5bf9\u8c61\u540c\u540d\u3002\u5f53\u7528IMPDP\u5de5\u5177\u6216\u8005IMP\u5de5\u5177\u5bfc\u5165\u5176\u4ed6\u5bf9\u8c61\u65f6\uff0c\u5982\u53d1\u73b0\u6709\u540c\u540d\u7684\u5bf9\u8c61\uff0c\u5c06\u4f1a\u51fa\u9519
\u8bed\u6cd5\uff1a
ALTER TABLE table_name RENAME CONSTRAINT old_constraint_name
TO new_constraint_name;
SQL> ALTER TABLE T1 rename constraint pk_t1_id to pk_t1_idnew
 2 ;<\/p>\n

Table altered.<\/p>\n

3 \u7981\u6b62\u7ea6\u675f<\/p>\n

\u7981\u6b62\u7ea6\u675f\u6307\u4f7f\u7ea6\u675f\u4e34\u65f6\u5931\u6548\u3002\u5f53\u7981\u6b62\u4e86\u7ea6\u675f\u4e4b\u540e\uff0c\u7ea6\u675f\u89c4\u5219\u5c06\u4e0d\u518d\u751f\u6548\u3002\u5728\u4f7f\u7528SQL*LOADER\u6216INSERT\u88c5\u8f7d\u6570\u636e\u4e4b\u524d\uff0c\u4e3a\u4e86\u52a0\u5feb\u6570\u636e\u88c5\u8f7d\u901f\u5ea6\uff0c\u5e94\u8be5\u9996\u5148\u7981\u6b62\u7ea6\u675f\uff0c\u7136\u540e\u88c5\u8f7d\u6570\u636e\u3002
\u8bed\u6cd5\uff1a
ALTER TABLE table_name
DISABLE CONSTRAINT constaint_name [CASCAED];–CASCAED\u7528\u4e8e\u6307\u5b9a\u7ea7\u8054\u7981\u6b62\u4ece\u8868\u7684\u5916\u90e8\u952e
SQL> ALTER TABLE T2 DISABLE constraint pk_t2_id;<\/p>\n

Table altered.
4 \u6fc0\u6d3b\u7ea6\u675f<\/p>\n

\u8bed\u6cd5\uff1a
ALTER TABLE table_name ENABLE CONSTRAINT constraint_name;
SQL> ALTER TABLE T2 enABLE constraint pk_t2_id;<\/p>\n

Table altered.
5 \u5220\u9664\u7ea6\u675f<\/p>\n

\u5f53\u5220\u9664\u7279\u5b9a\u8868\u7684\u4e3b\u952e\u7ea6\u675f\u65f6\uff0c\u5982\u679c\u8be5\u8868\u5177\u6709\u76f8\u5173\u7684\u4ece\u8868\uff0c\u90a3\u4e48\u5728\u5220\u9664\u4e3b\u952e\u7ea6\u675f\u65f6\u5fc5\u987b\u5e26\u6709CASCAED\u9009\u9879
\u8bed\u6cd5\uff1a
ALTER TABLE table_name DROP
CONSTRAINT constraint_name |PRIMARY KEY
SQL> ALTER TABLE T3 drop constraint ck_t3_sal;<\/p>\n

Table altered.
6 \u663e\u793a\u4fe1\u606f<\/p>\n

1.USER_CONSTRAINTS
2.USER_CONS_COLUMNS
3.SQL> set line 100
SQL> col CONSTRAINT_NAME format A20
SQL> col table_NAME format A20
SQL> col column_NAME format A20
SQL> select constraint_name,table_name,column_name from user_cons_columns where table_name=’T1′;<\/p>\n

CONSTRAINT_NAME TABLE_NAME COLUMN_NAME<\/p>\n

PK_T1_ID T1 ID<\/p>\n

Table created.<\/p>\n

SQL> alter table t3 add constraint ck_t3_sal check(sal>5000);<\/p>\n

Table altered.<\/p>\n

\u672c\u6587\u6c38\u4e45\u66f4\u65b0\u94fe\u63a5\u5730\u5740<\/strong><\/span>\uff1ahttp:\/\/www.linuxidc.com\/Linux\/2018-01\/150062.htm<\/p>\n

\"Oracle<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

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\n\u5728Oracle\u4e2d\uff0c\u6570\u636e\u5b8c\u6574\u6027\u53ef\u4ee5\u4f7f\u7528\u7ea6\u675f\u3001\u89e6\u53d1\u5668\u3001\u5e94\u7528\u7a0b\u5e8f\uff08\u8fc7\u7a0b\u3001\u51fd\u6570\uff09\u4e09\u79cd\u65b9\u6cd5\u6765\u5b9e\u73b0\uff0c\u5728\u8fd9\u4e09\u79cd\u65b9\u6cd5\u4e2d\uff0c\u56e0\u4e3a\u7ea6\u675f\u6613\u4e8e\u7ef4\u62a4\uff0c\u5e76\u4e14\u5177\u6709\u6700\u597d\u7684\u6027\u80fd\uff0c\u6240\u4ee5\u4f5c\u4e3a\u7ef4\u62a4\u6570\u636e\u5b8c\u6574\u6027\u7684\u9996\u9009\u3002<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[],"tags":[],"class_list":["post-209852","post","type-post","status-publish","format-standard","hentry"],"_links":{"self":[{"href":"https:\/\/www.dongwubaike.cn\/fanhao\/wp-json\/wp\/v2\/posts\/209852","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.dongwubaike.cn\/fanhao\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.dongwubaike.cn\/fanhao\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.dongwubaike.cn\/fanhao\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.dongwubaike.cn\/fanhao\/wp-json\/wp\/v2\/comments?post=209852"}],"version-history":[{"count":1,"href":"https:\/\/www.dongwubaike.cn\/fanhao\/wp-json\/wp\/v2\/posts\/209852\/revisions"}],"predecessor-version":[{"id":308312,"href":"https:\/\/www.dongwubaike.cn\/fanhao\/wp-json\/wp\/v2\/posts\/209852\/revisions\/308312"}],"wp:attachment":[{"href":"https:\/\/www.dongwubaike.cn\/fanhao\/wp-json\/wp\/v2\/media?parent=209852"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.dongwubaike.cn\/fanhao\/wp-json\/wp\/v2\/categories?post=209852"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.dongwubaike.cn\/fanhao\/wp-json\/wp\/v2\/tags?post=209852"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}