{"id":583,"date":"2010-08-24T13:31:00","date_gmt":"2010-08-24T05:31:00","guid":{"rendered":"http:\/\/note.systw.net\/note\/?p=583"},"modified":"2023-11-04T13:33:08","modified_gmt":"2023-11-04T05:33:08","slug":"sql-ddl","status":"publish","type":"post","link":"https:\/\/systw.net\/note\/archives\/583","title":{"rendered":"SQL DDL"},"content":{"rendered":"\n

DDL<\/p>\n\n\n\n

\u5efa\u7acb\u8cc7\u6599\u8868
create table < tablename>(
< column> < datatype> [column constraint],
[other constraint]
)<\/strong><\/p>\n\n\n\n

datatype\u5e38\u7528\u7684\u6709\u4ee5\u4e0b
\u3000varchar<\/strong> \u8b8a\u52d5\u6b04\u4f4d,\u4f9d\u8cc7\u6599\u91cf\u591a\u5c11\u6703\u7d66\u4e0d\u540c\u7684\u7a7a\u9593
\u3000char<\/strong> \u56fa\u5b9a\u6b04\u4f4d
column constraint\u5e38\u7528\u7684\u6709\u4ee5\u4e0b
\u3000default 0<\/strong> \u82e5\u7121\u8cc7\u6599\u9810\u8a2d\u70ba0
\u3000not null<\/strong> \u8cc7\u6599\u4e0d\u53ef\u70ba\u7a7a\u503c
\u3000primary key<\/strong> \u8a2d\u5b9a\u4e3b\u9375
\u3000reference table(column)<\/strong> \u8a2d\u5b9a\u5916\u4f86\u9375
\u3000check(\u689d\u4ef6)<\/strong> \u8a2d\u5b9a\u8f38\u5165\u8cc7\u6599\u7684\u6b04\u4f4d\u9650\u5236
other constraint\u5e38\u7528\u7684\u6709\u4ee5\u4e0b
\u3000primary key(< column>)<\/strong> \u8a2d\u5b9a\u4e3b\u9375
\u3000foreign key(column) references table(column)<\/strong> \u8a2d\u5b9a\u5916\u4f86\u9375
\u3000check(\u689d\u4ef6)<\/strong> \u8a2d\u5b9a\u8f38\u5165\u8cc7\u6599\u7684\u6b04\u4f4d\u9650\u5236
ex:
column1\u548ccolumn2\u4e0d\u53ef\u540c\u6642\u70banull
check(column1 is not null or column2 is not null)
ex:
column1\u8cc7\u6599\u8981\u5927\u65bc0
check(column1 > 0)<\/p>\n\n\n\n

\u8a2d\u5b9a\u4e3b\u9375<\/strong>
\u6709\u4ee5\u4e0b2\u7a2e\u5beb\u6cd5
< column> < datetype> primary key<\/strong>
\u3000\u5e38\u7528,\u5beb\u5728column constraint\u5340\u57df
\u3000\u6307\u5b9a\u8a72\u6b04\u4f4d\u70baprimay key,\u7f3a\u9ede\u662f\u53ea\u53ef\u4ee5\u8a2d\u5b9a\u4e00\u500b\u6b04\u4f4d
[option] primary key(< column>)<\/strong>
\u3000\u5beb\u5728other constraint\u5340\u57df
\u3000\u5ba3\u544aprimary key\u662f\u90a3\u4e9b\u6b04\u4f4d,\u53ef\u4ee5\u8a2d\u5b9a\u591a\u500b\u6b04\u4f4d
\u3000option\u5305\u62ec
\u3000\u3000constraint < name><\/strong> \u6307\u5b9aconstraint\u540d\u7a31,\u4e5f\u5c31\u662fkey\u7de8\u865f\u7684\u540d\u7a31<\/p>\n\n\n\n

ex:
\u5efa\u7acb\u8cc7\u6599\u8868department(dname,dnumber,mgr_ssn,mgr_start_date),\u8a9e\u6cd5\u5927\u81f4\u5982\u4e0b
create table department
(
dname varchar(20),
dnumber char(1) primary key not null,
mgr_ssn char(8) ,
mgr_start_date varchar(20)
)<\/p>\n\n\n\n

…..<\/p>\n\n\n\n

\u5b9a\u7fa9\u8cc7\u6599\u8868\u9650\u5236<\/strong>
\u5728\u4e3b\u9375\u8cc7\u6599\u8b8a\u52d5\u6642,\u5916\u4f86\u9375\u7684\u8655\u7406<\/p>\n\n\n\n

\u65b0\u589e\u8cc7\u6599\u6642\u53ef\u80fd\u9055\u53cd\u7684\u9650\u5236\u6709<\/strong>
\u3000\u5be6\u9ad4\u9650\u5236
\u3000\u5b9a\u7fa9\u57df\u9650\u5236
\u3000\u53c3\u8003\u5b8c\u6574\u6027\u9650\u5236
\u3000\u4f7f\u7528\u8005\u5b9a\u7fa9
\u89e3\u6c7a\u65b9\u5f0f<\/strong>
\u3000Restrict<\/strong>:\u62d2\u7d55\u65b0\u589e<\/p>\n\n\n\n

\u522a\u9664\u8cc7\u6599\u6642\u53ef\u80fd\u9055\u53cd\u7684\u9650\u5236\u6709<\/strong>
\u3000\u53c3\u8003\u5b8c\u6574\u6027\u9650\u5236
\u89e3\u6c7a\u65b9\u5f0f<\/strong>
\u3000Restrict<\/strong>:\u62d2\u7d55\u522a\u9664
\u3000Delete Cascade<\/strong>:\u9023\u9396\u6027\u522a\u9664
\u3000Set to Null Value<\/strong>: \u5c07\u53c3\u8003\u5230\u88ab\u522a\u9664\u7d00\u9304\u4e4b\u5916\u4f86\u9375\u503c\u8a2d\u6210\u7a7a\u503c<\/p>\n\n\n\n

\u66f4\u65b0\u8cc7\u6599\u6642\u53ef\u80fd\u9055\u53cd\u7684\u9650\u5236\u6709<\/strong>
\u3000\u5be6\u9ad4\u9650\u5236(\u53ea\u6709\u4e3b\u9375\u6216\u5916\u4f86\u9375\u624d\u6709\u53ef\u80fd\u9055\u53cd\u8a72\u9805\u76ee)
\u3000\u5b9a\u7fa9\u57df\u9650\u5236
\u3000\u53c3\u8003\u5b8c\u6574\u6027\u9650\u5236(\u53ea\u6709\u4e3b\u9375\u6216\u5916\u4f86\u9375\u624d\u6709\u53ef\u80fd\u9055\u53cd\u8a72\u9805\u76ee)
\u3000\u4f7f\u7528\u8005\u5b9a\u7fa9
\u89e3\u6c7a\u65b9\u5f0f<\/strong>
\u3000Restrict<\/strong>:\u62d2\u7d55\u66f4\u65b0
\u3000Update Cascade<\/strong>:\u9023\u9396\u6027\u66f4\u65b0
\u3000Set to Null Value<\/strong>:\u5c07\u53c3\u8003\u4e0d\u5230\u7236\u8cc7\u6599\u8868\u7684\u5916\u4f86\u9375\u503c\u8a2d\u70ba\u7a7a\u503c<\/p>\n\n\n\n

…….<\/p>\n\n\n\n

\u8a2d\u5b9a\u5916\u4f86\u9375<\/strong>
\u6709\u4ee5\u4e0b2\u7a2e\u5beb\u6cd5
< column> < datetype> references table(column) [option]<\/strong>
\u3000\u5beb\u5728column constraint\u5340\u57df
foreign key(column) references table(column) [option]<\/strong>
\u3000\u5beb\u5728other constraint\u5340\u57df
option\u5305\u62ec
on < delete|update> cascade<\/strong> \u7528\u5728forigen key\u53ef\u7522\u751f\u9023\u9396\u522a\u9664\u6216\u9023\u9396\u66f4\u65b0
\u3000\u7576\u53e6\u4e00\u500btable\u7684pk\u7570\u52d5\u6642\uff0c\u4e5f\u6703\u5f71\u97ff\u672ctable\u7684fk\u503c
\u3000\u7576fk\u540c\u6642\u70bapk\uff0c\u5728\u53e6\u4e00\u908atable\u7684pk\u7570\u52d5\u6642\u6703\u9023\u9396\u5f71\u97ff\u672ctable\u8cc7\u6599
\u3000\u7576\u50c5\u505afk\uff0c\u5728\u53e6\u4e00\u908atable\u7684pk\u7570\u52d5\u6642\u6703\u9023\u9396\u5f71\u97ff\u672ctable\u8cc7\u6599
on < delete|update> no action<\/strong> \u7528\u5728forigen key\u5247\u4e0d\u52d5\u4f5c
\u3000\u7576\u53e6\u4e00\u500btable\u7684pk\u7570\u52d5\u6642\uff0c\u672ctable\u7684fk\u4e0d\u6703\u53d7\u5f71\u97ff
\u3000\u7576fk\u540c\u6642\u70bapk\uff0c\u5728\u53e6\u4e00\u908atable\u7684pk\u7570\u52d5\u6642\u6703\u672ctable\u6703\u767c\u751f\u932f\u8aa4
\u3000\u50c5\u505afk\uff0c\u5728\u53e6\u4e00\u908atable\u7684pk\u7570\u52d5\u6642\u4e0d\u6703\u5f71\u97ff\u672ctable
ps:
\u5916\u4f86\u9375\u4e0d\u5efa\u8b70\u8207table\u540c\u6642\u5efa\u7acb
\u5efa\u8b70\u4f7f\u7528alter\u8a9e\u6cd5\u5728table\u5efa\u5b8c\u5f8c\u5728\u4fee\u6539\u8a72\u6b04\u4f4d\u70ba\u5916\u4f86\u9375<\/p>\n\n\n\n

………………………………………………………………………………………………………….<\/p>\n\n\n\n

\u4fee\u6539\u8cc7\u6599\u8868<\/strong>
ALTER TABLE < tablename> < action><\/strong><\/p>\n\n\n\n

\u5e38\u7528action\u6709\u4ee5\u4e0b
\u4fee\u6539\u6b04\u4f4d\u5c6c\u6027\u70baforeign key<\/strong>
alter table < tablename> add [constraint < name>] foreign key(< column>) references < table(column)> [option]
\u4fee\u6539\u6b04\u4f4ddata type<\/strong>
alter table < tablename> alter column < name> < datatype>
\u79fb\u9664foreign key\u5c6c\u6027<\/strong>
alter table < tablename> drop constraint < name><\/p>\n\n\n\n

ps:
constraint name\u6703\u8a18\u9304\u5728sysobjects
sysobjects\u8cc7\u6599\u8868\u7684xtype\u6b04\u4f4d,\u82e5\u70baF\u8868\u793a\u5916\u4f86\u9375
ex:select * from sysobjects where xtype=’F’<\/p>\n\n\n\n

…………………………………………………………………………………………………………<\/p>\n\n\n\n

\u522a\u9664\u8cc7\u6599\u8868
DROP TABLE < tablename><\/strong>
ps:
\u901a\u5e38\u522a\u9664\u7684\u9806\u5e8f\u6703\u548c\u5efa\u7acb\u7684\u9806\u5e8f\u76f8\u53cd
\u82e5\u88ab\u5176\u4ed6table\u53c3\u8003\u6642,\u6703\u7121\u6cd5\u522a\u9664
\u82e5\u5169table\u4e92\u76f8\u53c3\u8003\u5c0d\u65b9,\u9700\u5148\u79fb\u9664foreign key\u5c6c\u6027<\/p>\n\n\n\n


…………………………………………………………………………………………………………<\/p>\n\n\n\n


\u5efa\u7acbVIEW
CREATE VIEW < viewname> AS < select sql><\/p>\n\n\n\n

\u5efa\u7acbtrigger
CREATE TRIGGER < name> ON [order details] FOR < insert,update,delete> AS < sql><\/p>\n\n\n\n

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

DDL \u5efa\u7acb\u8cc7\u6599\u8868create table < tab …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"fifu_image_url":"","fifu_image_alt":"","_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[16],"tags":[],"class_list":["post-583","post","type-post","status-publish","format-standard","hentry","category-database"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts\/583","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/comments?post=583"}],"version-history":[{"count":0,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts\/583\/revisions"}],"wp:attachment":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/media?parent=583"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/categories?post=583"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/tags?post=583"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}