{"id":8734,"date":"2009-10-10T12:56:00","date_gmt":"2009-10-10T12:56:00","guid":{"rendered":"http:\/\/melotopia.net\/b\/?p=8734"},"modified":"2009-10-10T12:56:00","modified_gmt":"2009-10-10T12:56:00","slug":"db%ec%88%99%ec%a0%9c-%ec%99%84%ec%a0%84-otl","status":"publish","type":"post","link":"http:\/\/melotopia.net\/b\/?p=8734","title":{"rendered":"DB\uc219\uc81c – \uc644\uc804 OTL"},"content":{"rendered":"
\n DB \uc219\uc81c\ub97c \ud558\ub2e4\uac00 1\uc8fc\uc77c\uc744 \ub0a0\ub824\uba39\uc5c8\ub2e4.<\/p>\n

\ucc98\uc74c\uc740 \uc27d\ub2e4.
\n
\n A\ud14c\uc774\ube14\uc5d0\uc11c \uce7c\ub7fc a\uc640 b\ub97c \ucd9c\ub825\ud574\ub77c
\n
\n SELECT a, b FROM A<\/p>\n

\ub450\ubc88\uc9f8\ub3c4 \uc27d\ub2e4. B\ud14c\uc774\ube14\uc5d0\uc11c a, b, c\ub97c \ucd9c\ub825\ud558\ub294\ub370 c\uac00 ‘abc’\uc778 \uac83\ub9cc \ucd9c\ub825\ud574\ub77c
\n
\n SELECT a, b, c FROM B WHERE c=’abc’<\/p>\n

\uc138\ubc88\uc9f8\uac00 1\uc8fc\uc77c\uc744 \ub9d0\uc544\uba39\uc740 \uadf8 \ubb38\uc81c\ub2e4. C\ub294 A\uc640 B\uc758 \uad00\uacc4 \ud14c\uc774\ube14\uc778\ub370, C\uc5d0 \uad00\uacc4\uac00 \uc788\ub294 \uac83\ub4e4\ub9cc A\uc640 B\uc5d0\uc11c \ucc3e\uc544\uc11c A\uc758 a\uce7c\ub7fc\uacfc B\uc758 a\uce7c\ub7fc\uc744 \ucd9c\ub825\ud574\ub77c.
\n
\n \uc774\uac78 1\uac1c\uc758 Select\ub85c \ucc98\ub9ac\ud558\ub824\uace0 \ud558\ub2c8 \uc548\ub41c\ub2e4. Join\uc9c8\uc758\ub294 \ud55c\ubc88\uc5d0 2\uac1c\uae4c\uc9c0\ub9cc \ubc1b\uc544\uc8fc\uace0 3\uac1c\ub294 \ubabb\ubc1b\ub354\ub77c. \uadf8\ub798\uc11c View\ub97c \ud558\ub098 \ub9cc\ub4e4\uc5c8\ub2e4.
\n
\n CREATE VIEW D AS SELECT A.a, A.b, C.c FROM A JOIN C ON A.b=C.c
\n
\n \uadf8\ub9ac\uace0
\n
\n SELECT A.a, B.b FROM B JOIN D ON B.b=D.b
\n
\n \uc774\ub807\uac8c \ucc98\ub9ac\ud588\ub2e4.<\/p>\n

\uadf8\ub807\uac8c \ud588\ub354\ub2c8 \ub124\ubc88\uc9f8\ub294 \uc880 \uc26c\uc6e0\ub2e4. C\ud14c\uc774\ube14\uc5d0 \uad00\uacc4\uac00 \uc788\ub294 \uac83\ub4e4\uc911\uc5d0 A\ud14c\uc774\ube14\uc758 PK\ubcc4\ub85c B\uc5d0 \uc788\ub294 c\uce7c\ub7fc \ud56d\ubaa9\uc758 \ud569\uc744 \ucd9c\ub825\ud574\ub77c. \uc704\uc758 View\ub97c B.c\ub97c \ud3ec\ud568\ud558\ub3c4\ub85d \uc870\uae08 \uace0\uccd0\uc8fc\uace0
\n
\n SELECT sum(B.c) FROM A JOIN D ON A.a=C.c GROUP BY A.a<\/p>\n

\uc774\ub807\uac8c \ud588\ub2e4.<\/p>\n

\uadf8\ub9ac\uace0 \ub9c8\uc9c0\ub9c9 \ubb38\uc81c…\uc644\uc804 \ub9c9\uc7a5\uc774\ub2e4.
\n
\n C\ud14c\uc774\ube14\uc5d0 \uad00\uacc4\uac00 \uc788\ub294 E\ud14c\uc774\ube14\uc758 a\uce7c\ub7fc\uc774 ‘abc’\uc774\uba74\uc11c B\ud14c\uc774\ube14\uc758 b\uce7c\ub7fc\uc774 ‘def’\uc778 A\ud14c\uc774\ube14\uc758 a, b \uce7c\ub7fc\uacfc B\ud14c\uc774\ube14\uc758 d\uce7c\ub7fc\uacfc E\ud14c\uc774\ube14\uc758 b\uce7c\ub7fc\uc744 \ucd9c\ub825\ud574\ub77c.<\/p>\n

\uc5b4\ub5bb\uac8c \ud574\uc57c \ud558\ub098 \uace0\ubbfc\uc911\uc774\ub2e4. View\ub97c \ud558\ub098 \ub354 \ub9cc\ub4e4\uc5b4\uc57c \ud558\ub098…<\/p>\n

*\uc219\uc81c\ub77c\uc11c \ud45c\uc808\uc2dc\ube44\uc5d0 \ud718\ub9d0\ub9ac\uba74 \uc548\ub418\ubbc0\ub85c \ub0b4\uc6a9\uc744 \uc804\ud600 \uc54c\uc218 \uc5c6\uac8c \ucc98\ub9ac\ud588\ub2e4.<\/p>\n

*\ucd94\uac00. Instance\ub97c 7\uac1c \uc774\uc0c1(\uac01 \ud14c\uc774\ube14\uc5d0 7\uac74 \uc774\uc0c1) \uc785\ub825\ud574\uc57c \ud55c\ub2e4\ub294 \uc870\uac74\uc744 \uc774\uc81c \ubc1c\uacac\ud588\ub2e4. \ucc98\uc74c\ubd80\ud130 \ub2e4\uc2dc \ud574\uc57c \ud55c\ub2e4. -_-;;; \uc81c\ucd9c\uc5d0 \ud654\uba74 \ucea1\uccd0\uae4c\uc9c0 \ud3ec\ud568\uc774\uae30 \ub54c\ubb38\uc5d0 \ud654\uba74 \ucea1\uccd0\ub97c \ud558\ub824\uba74 \ucc98\uc74c\ubd80\ud130 \ub2e4\uc2dc \ud574\uc57c \ud55c\ub2e4\ub294 \ub73b. \uadfc\ub370 SQL Plus\uc5d0\uc120 \ubd99\uc5ec\ub123\uae30\uac00 \uc548\ub41c\ub2e4. \uad50\uc218\uac00 \uc774\uac78 \uc54c\uace0 \uc624\ub77c\ud074\uc740 SQL Plus\ub97c \uc4f0\ub77c\uace0 \uc2dc\ud0a8 \uac78\uae4c?<\/p>\n

*\ub610 \ucd94\uac00. \uad50\uc7ac\uc5d0 \uc624\ud0c0\uac00 \ub108\ubb34 \ub9ce\ub2e4. \uadf8\uac83\ub3c4 \uc124\uba85\ubb38\uc774 \uc544\ub2c8\ub77c \uc608\uc81c\ub85c \ub098\uc628 \uba85\ub839\ubb38\uc5d0 \uc624\ud0c0\uac00 \ub9ce\ub2e4. \uc608\uc81c \uadf8\ub300\ub85c \uc785\ub825\ud588\ub294\ub370 \uc2e4\ud589\ub418\uc9c8 \uc54a\uc544\uc11c \uc778\ud130\ub137\uc744 \ucc3e\uc544\ubcf4\ub2c8 \ucc45\uc774 \ud2c0\ub838\ub354\ub77c. \uc81c\ubc1c…\u315c_\u315c
\n
\n \ucd08\ubcf4\uc790\ub4e4\uc740 \uad50\uc7ac \ub0b4\uc6a9, \ud2b9\ud788 \uadf8\uc911\uc5d0\uc11c\ub3c4 \uc608\uc81c\ub9cc \ubbff\uace0 \uac00\ub294\ub370 \ucef4\ud4e8\ud130 \uad50\uc7ac\ub294 \uc81c\ubc1c \uc608\uc81c\uc5d0\ub294 \uc624\ub958\uac00 \uc5c6\uc5c8\uc73c\uba74 \uc88b\uaca0\ub2e4.
\n <\/p>\n

\n
\n
\n\"\uc2e0\uace0\"
\n<\/a>\n<\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

DB \uc219\uc81c\ub97c \ud558\ub2e4\uac00 1\uc8fc\uc77c\uc744 \ub0a0\ub824\uba39\uc5c8\ub2e4. \ucc98\uc74c\uc740 \uc27d\ub2e4. A\ud14c\uc774\ube14\uc5d0\uc11c \uce7c\ub7fc a\uc640 b\ub97c \ucd9c\ub825\ud574\ub77c SELECT a, b FROM A \ub450\ubc88\uc9f8\ub3c4 \uc27d\ub2e4. B\ud14c\uc774\ube14\uc5d0\uc11c a, b, c\ub97c \ucd9c\ub825\ud558\ub294\ub370 c\uac00 ‘abc’\uc778 \uac83\ub9cc \ucd9c\ub825\ud574\ub77c SELECT a, b, c FROM B WHERE c=’abc’ \uc138\ubc88\uc9f8\uac00 1\uc8fc\uc77c\uc744 \ub9d0\uc544\uba39\uc740 \uadf8 \ubb38\uc81c\ub2e4. C\ub294 A\uc640 B\uc758 \uad00\uacc4 \ud14c\uc774\ube14\uc778\ub370, C\uc5d0 \uad00\uacc4\uac00 \uc788\ub294 \uac83\ub4e4\ub9cc A\uc640 B\uc5d0\uc11c \ucc3e\uc544\uc11c A\uc758 a\uce7c\ub7fc\uacfc […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_crdt_document":"","_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[12],"tags":[],"class_list":["post-8734","post","type-post","status-publish","format-standard","hentry","category-12"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p8o6gA-2gS","jetpack-related-posts":[],"jetpack_likes_enabled":true,"_links":{"self":[{"href":"http:\/\/melotopia.net\/b\/index.php?rest_route=\/wp\/v2\/posts\/8734","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/melotopia.net\/b\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/melotopia.net\/b\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/melotopia.net\/b\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/melotopia.net\/b\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=8734"}],"version-history":[{"count":0,"href":"http:\/\/melotopia.net\/b\/index.php?rest_route=\/wp\/v2\/posts\/8734\/revisions"}],"wp:attachment":[{"href":"http:\/\/melotopia.net\/b\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=8734"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/melotopia.net\/b\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=8734"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/melotopia.net\/b\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=8734"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}