{"id":1650,"date":"2024-01-31T14:11:27","date_gmt":"2024-01-31T05:11:27","guid":{"rendered":"https:\/\/dohokin.com\/?p=1650"},"modified":"2024-01-31T14:11:27","modified_gmt":"2024-01-31T05:11:27","slug":"sql-%ec%a0%95%eb%a6%ac-%eb%85%b8%ed%8a%b8","status":"publish","type":"post","link":"https:\/\/dohokin.com\/?p=1650","title":{"rendered":"SQL \uc815\ub9ac \ub178\ud2b8"},"content":{"rendered":"\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" src=\"https:\/\/dohokin.com\/wp-content\/uploads\/2024\/01\/image-35.png\" alt=\"\" class=\"wp-image-1656\"\/><\/figure>\n\n\n\n<p>DBMS(Database Management System, \ub370\uc774\ud130\ubca0\uc774\uc2a4 \uad00\ub9ac \uc2dc\uc2a4\ud15c)\uc758 \uc8fc\uc694 \ud2b9\uc9d5 \uc911\uc5d0\uc11c &#8216;\ub370\uc774\ud130 \uc758\uc874\uc131(Data Dependency)&#8217;\uc740 DBMS\uc758 \ud2b9\uc9d5\uc774 \uc544\ub2d9\ub2c8\ub2e4. DBMS\uc758 \ud575\uc2ec \ud2b9\uc9d5\uc740 \ub2e4\uc74c\uacfc \uac19\uc2b5\ub2c8\ub2e4:<\/p>\n\n\n\n<ol>\n<li><strong>\ub370\uc774\ud130 \ubcf4\uc548\uc131(Data Security)<\/strong>: DBMS\ub294 \ub370\uc774\ud130\uc5d0 \ub300\ud55c \uc811\uadfc\uc744 \uc81c\uc5b4\ud558\uc5ec \ubb34\ub2e8 \uc811\uadfc\uc774\ub098 \ubcc0\uc870\ub97c \ubc29\uc9c0\ud569\ub2c8\ub2e4.<\/li>\n\n\n\n<li><strong>\ub370\uc774\ud130 \uc77c\uad00\uc131(Data Consistency)<\/strong>: DBMS\ub294 \ub370\uc774\ud130\uc758 \uc77c\uad00\uc131\uc744 \uc720\uc9c0\ud558\uba70, \uc5ec\ub7ec \uc0ac\uc6a9\uc790\uac00 \ub3d9\uc2dc\uc5d0 \ub370\uc774\ud130\ub97c \uc0ac\uc6a9\ud560 \ub54c \ubc1c\uc0dd\ud560 \uc218 \uc788\ub294 \ucda9\ub3cc\uc744 \uad00\ub9ac\ud569\ub2c8\ub2e4.<\/li>\n\n\n\n<li><strong>\ub370\uc774\ud130 \ubb34\uacb0\uc131(Data Integrity)<\/strong>: DBMS\ub294 \ub370\uc774\ud130\uac00 \uc815\ud655\ud558\uace0 \uc720\ud6a8\ud55c \uc0c1\ud0dc\ub97c \uc720\uc9c0\ud558\ub3c4\ub85d \ud569\ub2c8\ub2e4.<\/li>\n<\/ol>\n\n\n\n<p>\ubc18\uba74\uc5d0, &#8216;\ub370\uc774\ud130 \uc758\uc874\uc131(Data Dependency)&#8217;\uc740 \uc77c\ubc18\uc801\uc73c\ub85c DBMS\uc758 \ub2e8\uc810\uc774\ub098 \ud55c\uacc4\ub85c \uc5b8\uae09\ub429\ub2c8\ub2e4. \ub370\uc774\ud130\ubca0\uc774\uc2a4 \uc2dc\uc2a4\ud15c\uc5d0\uc11c \ub370\uc774\ud130 \uc758\uc874\uc131\uc774\ub780 \ub370\uc774\ud130\uc758 \uad6c\uc870\uac00 \ud504\ub85c\uadf8\ub7a8 \ub85c\uc9c1\uacfc \ubc00\uc811\ud558\uac8c \uc5f0\uacb0\ub418\uc5b4 \uc788\uc5b4, \ub370\uc774\ud130 \uad6c\uc870\uac00 \ubcc0\uacbd\ub420 \ub54c \uad00\ub828 \ud504\ub85c\uadf8\ub7a8\ub3c4 \ud568\uaed8 \ubcc0\uacbd\ud574\uc57c \ud558\ub294 \uc0c1\ud669\uc744 \uc758\ubbf8\ud569\ub2c8\ub2e4. \uadf8\ub7ec\ub098 \ud604\ub300\uc758 DBMS\ub294 \ub370\uc774\ud130\uc640 \uc751\uc6a9 \ud504\ub85c\uadf8\ub7a8 \uac04\uc758 \ub3c5\ub9bd\uc131\uc744 \uc81c\uacf5\ud558\uae30 \uc704\ud574 \uc124\uacc4\ub418\uc5c8\uc2b5\ub2c8\ub2e4. \ub530\ub77c\uc11c, &#8216;\ub370\uc774\ud130 \uc758\uc874\uc131&#8217;\uc740 DBMS\uc758 \ud2b9\uc9d5\uc774\ub77c\uae30\ubcf4\ub2e4\ub294 DBMS\ub97c \uc0ac\uc6a9\ud568\uc73c\ub85c\uc368 \uadf9\ubcf5\ud558\uace0\uc790 \ud558\ub294 \ubb38\uc81c \uc911 \ud558\ub098\uc785\ub2c8\ub2e4.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\uc2a4\ud0a4\ub9c8\ub294 \ub370\uc774\ud130\ubca0\uc774\uc2a4\uc5d0\uc11c \ub370\uc774\ud130\uc758 \uad6c\uc870\ub97c \uc815\uc758\ud558\uace0 \ud45c\ud604\ud558\ub294 \ubc29\ubc95\uc744 \ub098\ud0c0\ub0c5\ub2c8\ub2e4. \uc2a4\ud0a4\ub9c8\ub294 \ub370\uc774\ud130\ubca0\uc774\uc2a4\uc5d0 \uc800\uc7a5\ub418\ub294 \ub370\uc774\ud130\uc758 \ud615\uc2dd, \uad6c\uc870, \uad00\uacc4 \ub4f1\uc744 \uc815\uc758\ud558\uba70 \ub370\uc774\ud130\ubca0\uc774\uc2a4\uac00 \uc5b4\ub5bb\uac8c \uad6c\uc131\ub418\uc5b4 \uc788\ub294\uc9c0\ub97c \ub098\ud0c0\ub0b4\ub294 \uccad\uc0ac\uc9c4\uc774\ub77c\uace0 \ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4.<\/p>\n\n\n\n<p>\ub370\uc774\ud130\ubca0\uc774\uc2a4\uc758 \uc2a4\ud0a4\ub9c8\ub294 \ud06c\uac8c \ub450 \uac00\uc9c0 \uc720\ud615\uc73c\ub85c \ub098\ub20c \uc218 \uc788\uc2b5\ub2c8\ub2e4:<\/p>\n\n\n\n<ol>\n<li><strong>\ub17c\ub9ac\uc801 \uc2a4\ud0a4\ub9c8 (Logical Schema):<\/strong> \ub370\uc774\ud130\ubca0\uc774\uc2a4\uc758 \uad6c\uc870\ub97c \uc0ac\uc6a9\uc790 \ub610\ub294 \uc751\uc6a9 \ud504\ub85c\uadf8\ub798\uba38\uc758 \uad00\uc810\uc5d0\uc11c \uc815\uc758\ud569\ub2c8\ub2e4. \uc774\ub294 \ub370\uc774\ud130\ubca0\uc774\uc2a4\uc5d0 \uc5b4\ub5a4 \ub370\uc774\ud130\uac00 \uc800\uc7a5\ub418\ub294\uc9c0, \uadf8 \ub370\uc774\ud130 \uac04\uc758 \uad00\uacc4\uac00 \uc5b4\ub5bb\uac8c \ud615\uc131\ub418\ub294\uc9c0 \ub4f1\uc744 \ub098\ud0c0\ub0c5\ub2c8\ub2e4.<\/li>\n\n\n\n<li><strong>\ubb3c\ub9ac\uc801 \uc2a4\ud0a4\ub9c8 (Physical Schema):<\/strong> \ub370\uc774\ud130\uac00 \uc2e4\uc81c\ub85c \uc5b4\ub5bb\uac8c \uc800\uc7a5\ub418\ub294\uc9c0\ub97c \ub098\ud0c0\ub0c5\ub2c8\ub2e4. \ub514\uc2a4\ud06c\uc5d0 \uc800\uc7a5\ub418\ub294 \ubc29\uc2dd, \uc778\ub371\uc2a4\uc758 \uc0ac\uc6a9 \uc5ec\ubd80, \uc815\ub82c \ubc29\uc2dd \ub4f1\uacfc \uac19\uc740 \ubb3c\ub9ac\uc801\uc778 \uc138\ubd80 \uc0ac\ud56d\uc744 \uae30\uc220\ud569\ub2c8\ub2e4.<\/li>\n<\/ol>\n\n\n\n<p>\uc2a4\ud0a4\ub9c8\ub294 \ub370\uc774\ud130\uc758 \ubb34\uacb0\uc131\uc744 \ubcf4\uc7a5\ud558\uace0, \ub370\uc774\ud130\ubca0\uc774\uc2a4 \uc2dc\uc2a4\ud15c\uc774 \ub370\uc774\ud130\ub97c \ud6a8\uacfc\uc801\uc73c\ub85c \uad00\ub9ac\ud560 \uc218 \uc788\ub3c4\ub85d \ub3c4\uc640\uc90d\ub2c8\ub2e4. \uc2a4\ud0a4\ub9c8\ub97c \ud1b5\ud574 \ub370\uc774\ud130\ubca0\uc774\uc2a4\uc5d0 \uc5b4\ub5a4 \uc885\ub958\uc758 \ub370\uc774\ud130\uac00 \uc800\uc7a5\ub420\uc9c0, \uac01 \ub370\uc774\ud130\uc758 \uc18d\uc131\uc740 \ubb34\uc5c7\uc778\uc9c0, \uc5b4\ub5a4 \uc81c\uc57d \uc870\uac74\uc774 \uc874\uc7ac\ud558\ub294\uc9c0 \ub4f1\uc744 \uba85\ud655\ud558\uac8c \uc815\uc758\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\uad00\uacc4\ud615 \ub370\uc774\ud130 \ubaa8\ub378(Relational Data Model)\uc740 \ub370\uc774\ud130\ubca0\uc774\uc2a4 \uc124\uacc4\uc758 \uc8fc\uc694 \ud328\ub7ec\ub2e4\uc784 \uc911 \ud558\ub098\uc785\ub2c8\ub2e4. \uc774 \ubaa8\ub378\uc758 \uc8fc\uc694 \ud2b9\uc9d5\uc740 \ub2e4\uc74c\uacfc \uac19\uc2b5\ub2c8\ub2e4:<\/p>\n\n\n\n<ol>\n<li><strong>\ud14c\uc774\ube14 \uae30\ubc18 \uad6c\uc870<\/strong>: \ub370\uc774\ud130\ub294 \ud14c\uc774\ube14(table) \ud615\ud0dc\ub85c \uc800\uc7a5\ub429\ub2c8\ub2e4. \uac01 \ud14c\uc774\ube14\uc740 \ud589(row)\uacfc \uc5f4(column)\uc73c\ub85c \uad6c\uc131\ub418\uba70, \uac01 \ud589\uc740 \uac1c\ubcc4 \ub808\ucf54\ub4dc\ub97c \ub098\ud0c0\ub0b4\uace0, \uac01 \uc5f4\uc740 \ud2b9\uc815 \uc18d\uc131\uc744 \ub098\ud0c0\ub0c5\ub2c8\ub2e4.<\/li>\n\n\n\n<li><strong>\ud589\uacfc \uc5f4<\/strong>: \uac01 \ud589\uc740 \uace0\uc720\ud55c \ud0a4(\uc8fc\ub85c &#8216;\uae30\ubcf8 \ud0a4&#8217;\ub77c\uace0 \ud568)\ub97c \uac00\uc9c0\uba70, \uc774\ub97c \ud1b5\ud574 \ub808\ucf54\ub4dc\ub97c \uc2dd\ubcc4\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4. \uc5f4\uc740 \ubaa8\ub4e0 \ub808\ucf54\ub4dc\uc5d0 \ub300\ud574 \ub3d9\uc77c\ud55c \uc720\ud615\uc758 \ub370\uc774\ud130\ub97c \uc800\uc7a5\ud569\ub2c8\ub2e4.<\/li>\n\n\n\n<li><strong>\ub370\uc774\ud130 \ubb34\uacb0\uc131<\/strong>: \uad00\uacc4\ud615 \ubaa8\ub378\uc740 \ub370\uc774\ud130 \ubb34\uacb0\uc131\uc744 \uc720\uc9c0\ud558\ub294 \ub370 \uc911\uc810\uc744 \ub461\ub2c8\ub2e4. \uc774\ub97c \uc704\ud574 \uae30\ubcf8 \ud0a4(primary key), \uc678\ub798 \ud0a4(foreign key) \ubc0f \ub2e4\uc591\ud55c \ubb34\uacb0\uc131 \uaddc\uce59\uc744 \uc0ac\uc6a9\ud569\ub2c8\ub2e4.<\/li>\n\n\n\n<li><strong>SQL \uc0ac\uc6a9<\/strong>: \uad00\uacc4\ud615 \ub370\uc774\ud130\ubca0\uc774\uc2a4\ub294 \ub370\uc774\ud130 \uac80\uc0c9, \uc0bd\uc785, \uc218\uc815 \ubc0f \uc0ad\uc81c\ub97c \uc704\ud574 SQL(Structured Query Language)\uc744 \uc0ac\uc6a9\ud569\ub2c8\ub2e4. SQL\uc740 \uc120\uc5b8\uc801 \uc5b8\uc5b4\ub85c, \uc0ac\uc6a9\uc790\uac00 \uc6d0\ud558\ub294 \uacb0\uacfc\ub97c \uc5bb\uae30 \uc704\ud574 \uc5b4\ub5a4 \uc808\ucc28\ub97c \ub530\ub77c\uc57c \ud558\ub294\uc9c0\uac00 \uc544\ub2c8\ub77c, \uc6d0\ud558\ub294 \uacb0\uacfc\uac00 \ubb34\uc5c7\uc778\uc9c0\ub97c \uba85\uc2dc\ud569\ub2c8\ub2e4.<\/li>\n\n\n\n<li><strong>\uad00\uacc4\uc758 \uc815\uc758<\/strong>: \ub2e4\ub978 \ud14c\uc774\ube14 \uac04\uc758 \uad00\uacc4\ub294 \ud0a4\ub97c \ud1b5\ud574 \uc815\uc758\ub429\ub2c8\ub2e4. \uc774\ub7ec\ud55c \uad00\uacc4\ub97c \ud1b5\ud574 \uad00\ub828 \ub370\uc774\ud130 \uac04\uc758 \uc5f0\uacb0\uc744 \ud6a8\uc728\uc801\uc73c\ub85c \ub098\ud0c0\ub0bc \uc218 \uc788\uc2b5\ub2c8\ub2e4.<\/li>\n\n\n\n<li><strong>\uc2a4\ud0a4\ub9c8 \uae30\ubc18<\/strong>: \uad00\uacc4\ud615 \ubaa8\ub378\uc740 \ub370\uc774\ud130\ubca0\uc774\uc2a4 \uc2a4\ud0a4\ub9c8\ub97c \ud1b5\ud574 \ub370\uc774\ud130 \uad6c\uc870\ub97c \uc815\uc758\ud569\ub2c8\ub2e4. \uc2a4\ud0a4\ub9c8\ub294 \ub370\uc774\ud130\ubca0\uc774\uc2a4\uc758 \ub17c\ub9ac\uc801 \uad6c\uc870\ub97c \uc815\uc758\ud558\uace0, \ud14c\uc774\ube14, \ud544\ub4dc, \uadf8\ub9ac\uace0 \uc774\ub4e4 \uac04\uc758 \uad00\uacc4\ub97c \uba85\uc2dc\ud569\ub2c8\ub2e4.<\/li>\n\n\n\n<li><strong>\ud655\uc7a5\uc131\uacfc \uc720\uc5f0\uc131<\/strong>: \uad00\uacc4\ud615 \ubaa8\ub378\uc740 \ub2e4\uc591\ud55c \uc720\ud615\uacfc \uaddc\ubaa8\uc758 \uc751\uc6a9 \ud504\ub85c\uadf8\ub7a8\uc5d0 \uc801\ud569\ud558\uba70, \uc0c8\ub85c\uc6b4 \ub370\uc774\ud130\ub97c \ucd94\uac00\ud558\uac70\ub098 \uae30\uc874 \ub370\uc774\ud130 \uad6c\uc870\ub97c \ubcc0\uacbd\ud558\ub294 \ub370 \uc788\uc5b4 \uc0c1\ub300\uc801\uc73c\ub85c \uc720\uc5f0\ud569\ub2c8\ub2e4.<\/li>\n<\/ol>\n\n\n\n<p>\uc774\ub7ec\ud55c \ud2b9\uc9d5\ub4e4\ub85c \uc778\ud574 \uad00\uacc4\ud615 \ub370\uc774\ud130 \ubaa8\ub378\uc740 \uc624\ub298\ub0a0 \uac00\uc7a5 \ub110\ub9ac \uc0ac\uc6a9\ub418\ub294 \ub370\uc774\ud130\ubca0\uc774\uc2a4 \ubaa8\ub378 \uc911 \ud558\ub098\uac00 \ub418\uc5c8\uc2b5\ub2c8\ub2e4.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\uac01\uac01\uc758 \uc6a9\uc5b4\uc5d0 \ub300\ud55c \uac04\ub2e8\ud55c \uc124\uba85\uc740 \ub2e4\uc74c\uacfc \uac19\uc2b5\ub2c8\ub2e4:<\/p>\n\n\n\n<ol>\n<li><strong>PK (Primary Key):<\/strong><\/li>\n<\/ol>\n\n\n\n<ul>\n<li>Primary Key\ub294 \ub370\uc774\ud130\ubca0\uc774\uc2a4 \ud14c\uc774\ube14\uc5d0\uc11c \uac01 \ud589\uc744 \uace0\uc720\ud558\uac8c \uc2dd\ubcc4\ud558\ub294 \ub370 \uc0ac\uc6a9\ub418\ub294 \uc5f4\uc774\ub098 \uc5f4\uc758 \uc9d1\ud569\uc785\ub2c8\ub2e4.<\/li>\n\n\n\n<li>PK\ub294 \uc911\ubcf5\ub418\uc9c0 \uc54a\uc73c\uba70, NULL \uac12\uc744 \ud5c8\uc6a9\ud558\uc9c0 \uc54a\uc2b5\ub2c8\ub2e4.<\/li>\n\n\n\n<li>\ud14c\uc774\ube14\uc5d0\uc11c \uae30\ubcf8 \ud0a4\ub85c \uc120\ud0dd\ub41c \uc5f4\uc740 \ud574\ub2f9 \ud14c\uc774\ube14 \ub0b4\uc5d0\uc11c \uc720\uc77c\ud55c \uac12\uc744 \uac00\uc838\uc57c \ud569\ub2c8\ub2e4.<\/li>\n<\/ul>\n\n\n\n<ol>\n<li><strong>FK (Foreign Key):<\/strong><\/li>\n<\/ol>\n\n\n\n<ul>\n<li>Foreign Key\ub294 \ub2e4\ub978 \ud14c\uc774\ube14\uc758 Primary Key\uc640 \uad00\uacc4\ub97c \ub9fa\ub294\ub370 \uc0ac\uc6a9\ub418\ub294 \uc5f4\uc785\ub2c8\ub2e4.<\/li>\n\n\n\n<li>Foreign Key\ub294 \ucc38\uc870\ud558\ub294 \ud14c\uc774\ube14\uc758 Primary Key \uac12\uc774\ub098 Unique Key \uac12\uacfc \uc77c\uce58\ud574\uc57c \ud569\ub2c8\ub2e4.<\/li>\n\n\n\n<li>\uc678\ub798 \ud0a4 \uad00\uacc4\ub97c \ud1b5\ud574 \ud14c\uc774\ube14 \uac04\uc758 \uad00\uacc4\ub97c \uad6c\ucd95\ud558\uace0 \uc720\uc9c0\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4.<\/li>\n<\/ul>\n\n\n\n<ol>\n<li><strong>Row:<\/strong><\/li>\n<\/ol>\n\n\n\n<ul>\n<li>Row\ub294 \ud14c\uc774\ube14 \ub0b4\uc758 \ud558\ub098\uc758 \ub808\ucf54\ub4dc\ub97c \ub098\ud0c0\ub0c5\ub2c8\ub2e4.<\/li>\n\n\n\n<li>Row\ub294 \ud14c\uc774\ube14\uc5d0 \uc800\uc7a5\ub41c \uc2e4\uc81c \ub370\uc774\ud130\ub97c \uc758\ubbf8\ud558\uba70, \uac01 \uc5f4\uc5d0 \ud574\ub2f9\ud558\ub294 \ud544\ub4dc\uc758 \uac12\ub4e4\uc774 \ud3ec\ud568\ub429\ub2c8\ub2e4.<\/li>\n<\/ul>\n\n\n\n<ol>\n<li><strong>Column:<\/strong><\/li>\n<\/ol>\n\n\n\n<ul>\n<li>Column\uc740 \ud14c\uc774\ube14 \ub0b4\uc758 \ud558\ub098\uc758 \uc18d\uc131\uc744 \ub098\ud0c0\ub0c5\ub2c8\ub2e4.<\/li>\n\n\n\n<li>\ud14c\uc774\ube14\uc758 \uac01 Column\uc740 \ud2b9\uc815 \ub370\uc774\ud130 \uc720\ud615\uc5d0 \ub530\ub978 \ud544\ub4dc\ub97c \ub098\ud0c0\ub0b4\uba70, \uac01\uac01\uc758 Row\ub294 \ud574\ub2f9 Column\uc5d0 \uc18d\ud558\ub294 \uac12\uc744 \uac00\uc9c0\uace0 \uc788\uc2b5\ub2c8\ub2e4.<\/li>\n\n\n\n<li>Column\uc740 \ud2b9\uc815 \uc18d\uc131\uc774\ub098 \ub370\uc774\ud130 \uc720\ud615\uc744 \uac16\ub294 \uc5ec\ub7ec \uac1c\uc758 \ub370\uc774\ud130 \uac12\uc744 \ud3ec\ud568\ud569\ub2c8\ub2e4.<\/li>\n<\/ul>\n\n\n\n<p>\uc774\ub7ec\ud55c \uc6a9\uc5b4\ub4e4\uc740 \uad00\uacc4\ud615 \ub370\uc774\ud130\ubca0\uc774\uc2a4 \uc2dc\uc2a4\ud15c\uc5d0\uc11c \ud14c\uc774\ube14\uc744 \uc815\uc758\ud558\uace0 \ub370\uc774\ud130 \uac04\uc758 \uad00\uacc4\ub97c \uc124\uc815\ud558\ub294 \ub370 \uc0ac\uc6a9\ub429\ub2c8\ub2e4. Primary Key\uc640 Foreign Key\ub294 \ud2b9\ud788 \ud14c\uc774\ube14 \uac04\uc758 \uad00\uacc4\ub97c \ub9fa\ub294 \ub370 \uc911\uc694\ud55c \uc5ed\ud560\uc744 \ud569\ub2c8\ub2e4.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>RDBMS(Relational Database Management System)\uc758 \ub300\ud45c\uc801\uc778 \ub2e8\uc810 \uc911\uc5d0\uc11c &#8220;\uc6b4\uc601 \ube44\uc6a9\uc774 \ube44\uc308&#8221;\uc740 \uc0c1\ub300\uc801\uc73c\ub85c RDBMS\uc758 \ub2e8\uc810\uc774 \uc544\ub2d0 \uc218 \uc788\uc2b5\ub2c8\ub2e4. RDBMS\uc758 \uc8fc\uc694 \ub2e8\uc810\uc740 \ub2e4\uc74c\uacfc \uac19\uc2b5\ub2c8\ub2e4:<\/p>\n\n\n\n<ol>\n<li><strong>\ubbf8\ub9ac \ub9cc\ub4e4\uc5b4\uc9c4 \uc2a4\ud0a4\ub9c8 \uad6c\uc870\ub97c \ubcc0\uacbd \ub610\ub294 \ud655\uc7a5\ud558\ub294\ub370 \uc5b4\ub824\uc6c0<\/strong>: RDBMS\ub294 \uc2a4\ud0a4\ub9c8\uc5d0 \uae30\ubc18\ud55c \ub370\uc774\ud130 \uad6c\uc870\ub97c \uc0ac\uc6a9\ud558\uae30 \ub54c\ubb38\uc5d0, \uc2a4\ud0a4\ub9c8 \ubcc0\uacbd\uc774 \ud544\uc694\ud560 \uacbd\uc6b0 \uc774\ub97c \uc218\uc815\ud558\ub294 \ub370 \ubcf5\uc7a1\uc131\uacfc \uc2dc\uac04\uc774 \ub9ce\uc774 \uc18c\uc694\ub429\ub2c8\ub2e4.<\/li>\n\n\n\n<li><strong>\uc2e4\uc2dc\uac04 \ub370\uc774\ud130 \ucc98\ub9ac\uc758 \uc5b4\ub824\uc6c0<\/strong>: RDBMS\ub294 \ud2b8\ub79c\uc7ad\uc158 \ucc98\ub9ac\uc5d0 \ucd5c\uc801\ud654\ub418\uc5b4 \uc788\uc73c\ub098, \uace0\uc18d\uc758 \uc2e4\uc2dc\uac04 \ub370\uc774\ud130 \ucc98\ub9ac\ub098 \ube45\ub370\uc774\ud130 \ubd84\uc11d\uc5d0\ub294 \ud55c\uacc4\uac00 \uc788\uc744 \uc218 \uc788\uc2b5\ub2c8\ub2e4.<\/li>\n\n\n\n<li><strong>\ud14c\uc774\ube14 join\uc758 \ubcf5\uc7a1\uc131<\/strong>: \uad00\uacc4\ud615 \ub370\uc774\ud130\ubca0\uc774\uc2a4\uc5d0\uc11c \ub2e4\uc591\ud55c \ud14c\uc774\ube14 \uac04\uc758 \uad00\uacc4\ub97c \uad00\ub9ac\ud558\uace0, \uc774\ub97c \uc870\ud569\ud558\uae30 \uc704\ud574 join \uc5f0\uc0b0\uc744 \uc0ac\uc6a9\ud558\ub294\ub370, \uc774\ub294 \ubcf5\uc7a1\ud558\uace0 \uc131\ub2a5\uc5d0 \uc601\ud5a5\uc744 \uc904 \uc218 \uc788\uc2b5\ub2c8\ub2e4.<\/li>\n\n\n\n<li><strong>\ub300\ub7c9\uc758 \ub370\uc774\ud130\ub97c \uc800\uc7a5\ud558\ub294\uac8c \uc5b4\ub824\uc6c0<\/strong>: \ub300\uaddc\ubaa8 \ub370\uc774\ud130\uc14b\uc744 \ud6a8\uacfc\uc801\uc73c\ub85c \ucc98\ub9ac\ud558\ub294 \ub370 \uc788\uc5b4 RDBMS\ub294 \uc77c\uc815\ud55c \ud55c\uacc4\ub97c \uac00\uc9c0\uace0 \uc788\uc744 \uc218 \uc788\uc73c\uba70, \ube45\ub370\uc774\ud130\uc640 \uac19\uc740 \ub300\uc6a9\ub7c9\uc758 \ub370\uc774\ud130 \ucc98\ub9ac\uc5d0\ub294 NoSQL \ub370\uc774\ud130\ubca0\uc774\uc2a4 \uac19\uc740 \ub300\uc548\uc801\uc778 \uc811\uadfc \ubc29\uc2dd\uc774 \uc885\uc885 \uc0ac\uc6a9\ub429\ub2c8\ub2e4.<\/li>\n<\/ol>\n\n\n\n<p>\ubc18\uba74\uc5d0, &#8220;\uc6b4\uc601 \ube44\uc6a9\uc774 \ube44\uc308&#8221;\uc740 RDBMS\uc758 \ub2e8\uc810\uc73c\ub85c \uc77c\ubc18\uc801\uc73c\ub85c \uac04\uc8fc\ub418\uc9c0 \uc54a\uc2b5\ub2c8\ub2e4. \uc2e4\uc81c\ub85c, \ub9ce\uc740 \uc624\ud508 \uc18c\uc2a4 RDBMS \uc194\ub8e8\uc158\ub4e4\uc774 \uc874\uc7ac\ud558\uba70, \uc774\ub4e4\uc740 \ube44\uc6a9 \ud6a8\uc728\uc801\uc778 \ubc29\uc2dd\uc73c\ub85c \uc6b4\uc601\ub420 \uc218 \uc788\uc2b5\ub2c8\ub2e4. \ube44\uc6a9\uc740 RDBMS \uc120\ud0dd\uc5d0 \uc601\ud5a5\uc744 \uc904 \uc218 \uc788\uc9c0\ub9cc, \uc774\ub294 \uc77c\ubc18\uc801\uc73c\ub85c \uc8fc\uc694 \ub2e8\uc810\uc73c\ub85c \uc5ec\uaca8\uc9c0\uc9c0 \uc54a\uc2b5\ub2c8\ub2e4.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>&#8216;\ubb3c\ub9ac\uc801 \uc2a4\ud0a4\ub9c8&#8217;\ub294 <strong>\ub370\uc774\ud130\ubca0\uc774\uc2a4\uc758 \ubb3c\ub9ac\uc801 \uc800\uc7a5 \ubc29\uc2dd<\/strong>\uc744 \uc758\ubbf8\ud569\ub2c8\ub2e4. \uc774\ub294 \ub370\uc774\ud130\ubca0\uc774\uc2a4 \uc2dc\uc2a4\ud15c\uc758 \ub0b4\ubd80\uc801\uc778 \uad6c\uc870, \uc989 \ub370\uc774\ud130\uac00 \uc2e4\uc81c\ub85c \uc800\uc7a5\ub418\ub294 \ubc29\uc2dd\uacfc \uc800\uc7a5\ub41c \ub370\uc774\ud130\uc5d0 \uc811\uadfc\ud558\ub294 \ubc29\ubc95\uc744 \uc815\uc758\ud569\ub2c8\ub2e4. \ubb3c\ub9ac\uc801 \uc2a4\ud0a4\ub9c8\ub294 \ub514\uc2a4\ud06c\uc5d0 \ub370\uc774\ud130\uac00 \uc5b4\ub5bb\uac8c \uc800\uc7a5\ub418\ub294\uc9c0, \ub370\uc774\ud130\uc758 \uc800\uc7a5 \ud615\uc2dd, \uc778\ub371\uc2a4\uc758 \uad6c\uc870, \ud30c\uc77c \uacbd\ub85c, \ub370\uc774\ud130 \uc555\ucd95 \ubc29\ubc95 \ub4f1\uc744 \ud3ec\ud568\ud569\ub2c8\ub2e4.<\/p>\n\n\n\n<p>\ubc18\uba74, &#8216;\ub17c\ub9ac\uc801 \uad6c\uc870&#8217;\ub294 \ub370\uc774\ud130\ubca0\uc774\uc2a4\uc758 \ub17c\ub9ac\uc801 \uc2a4\ud0a4\ub9c8\uc640 \uad00\ub828\uc774 \uc788\uc73c\uba70, \uc774\ub294 \ub370\uc774\ud130\uc640 \ub370\uc774\ud130 \uac04\uc758 \uad00\uacc4\ub97c \uc815\uc758\ud569\ub2c8\ub2e4. &#8216;\ub370\uc774\ud130\ubca0\uc774\uc2a4\uc758 \uc0ac\uc6a9\uc790 \ubdf0&#8217;\ub294 \uc678\ubd80 \uc2a4\ud0a4\ub9c8\uc640 \uad00\ub828\ub418\uc5b4 \uc788\uc73c\uba70, \ud2b9\uc815 \uc0ac\uc6a9\uc790 \uadf8\ub8f9\uc5d0\uac8c \ub370\uc774\ud130\ub97c \uc5b4\ub5bb\uac8c \ubcf4\uc5ec\uc904 \uac83\uc778\uc9c0\ub97c \uc815\uc758\ud569\ub2c8\ub2e4. &#8216;\ub370\uc774\ud130\ubca0\uc774\uc2a4\uc758 \uc561\uc138\uc2a4 \uad8c\ud55c&#8217;\uc740 \ub370\uc774\ud130\ubca0\uc774\uc2a4\uc758 \ubcf4\uc548\uacfc \uad00\ub828\ub41c \ubd80\ubd84\uc73c\ub85c, \uc0ac\uc6a9\uc790 \ub610\ub294 \uc0ac\uc6a9\uc790 \uadf8\ub8f9\uc774 \ub370\uc774\ud130\uc5d0 \uc811\uadfc\ud560 \uc218 \uc788\ub294 \uad8c\ud55c\uc744 \uc124\uc815\ud558\ub294 \uac83\uc744 \uc758\ubbf8\ud569\ub2c8\ub2e4.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>SQL \uc5b8\uc5b4\uc5d0 \ud574\ub2f9\ud558\uc9c0 \uc54a\ub294 \uac83\uc740 <strong>\ub370\uc774\ud130 \uc5f0\uacb0 \uc5b8\uc5b4(DCL)<\/strong>\uc785\ub2c8\ub2e4. SQL(Structured Query Language)\uc758 \uc8fc\uc694 \uad6c\uc131 \uc694\uc18c\ub294 \ub2e4\uc74c\uacfc \uac19\uc2b5\ub2c8\ub2e4:<\/p>\n\n\n\n<ol>\n<li><strong>\ub370\uc774\ud130 \uc815\uc758 \uc5b8\uc5b4(DDL, Data Definition Language)<\/strong>: \ub370\uc774\ud130\ubca0\uc774\uc2a4\uc758 \uad6c\uc870\ub97c \uc815\uc758\ud558\ub294 \ub370 \uc0ac\uc6a9\ub429\ub2c8\ub2e4. \ud14c\uc774\ube14 \uc0dd\uc131, \uc218\uc815, \uc0ad\uc81c\uc640 \uac19\uc740 \uc791\uc5c5\uc744 \ud3ec\ud568\ud569\ub2c8\ub2e4. \uc608\ub97c \ub4e4\uba74, <code>CREATE<\/code>, <code>ALTER<\/code>, <code>DROP<\/code> \ub4f1\uc758 \uba85\ub839\uc5b4\uac00 \uc788\uc2b5\ub2c8\ub2e4.<\/li>\n\n\n\n<li><strong>\ub370\uc774\ud130 \uc81c\uc5b4 \uc5b8\uc5b4(DCL, Data Control Language)<\/strong>: \ub370\uc774\ud130\ubca0\uc774\uc2a4\uc758 \ubcf4\uc548\uacfc \uad8c\ud55c\uc744 \uad00\ub9ac\ud558\ub294 \ub370 \uc0ac\uc6a9\ub429\ub2c8\ub2e4. \uc0ac\uc6a9\uc790\uc5d0\uac8c \uad8c\ud55c\uc744 \ubd80\uc5ec\ud558\uac70\ub098 \ucde8\uc18c\ud558\ub294 \uc791\uc5c5\uc744 \ud3ec\ud568\ud569\ub2c8\ub2e4. <code>GRANT<\/code>, <code>REVOKE<\/code> \ub4f1\uc758 \uba85\ub839\uc5b4\uac00 \uc5ec\uae30\uc5d0 \uc18d\ud569\ub2c8\ub2e4.<\/li>\n\n\n\n<li><strong>\ub370\uc774\ud130 \ucc98\ub9ac \uc5b8\uc5b4(DML, Data Manipulation Language)<\/strong>: \ub370\uc774\ud130\ub97c \uc2e4\uc81c\ub85c \ucc98\ub9ac\ud558\ub294 \ub370 \uc0ac\uc6a9\ub429\ub2c8\ub2e4. \ub370\uc774\ud130\ub97c \uc870\ud68c, \uc0bd\uc785, \uc218\uc815, \uc0ad\uc81c\ud558\ub294 \uc791\uc5c5\uc744 \ud3ec\ud568\ud569\ub2c8\ub2e4. <code>SELECT<\/code>, <code>INSERT<\/code>, <code>UPDATE<\/code>, <code>DELETE<\/code> \ub4f1\uc758 \uba85\ub839\uc5b4\uac00 \uc774\uc5d0 \ud574\ub2f9\ud569\ub2c8\ub2e4.<\/li>\n<\/ol>\n\n\n\n<p>\ubc18\uba74\uc5d0 &#8220;\ub370\uc774\ud130 \uc5f0\uacb0 \uc5b8\uc5b4(DCL)&#8221;\uc740 SQL\uc758 \uad6c\uc131 \uc694\uc18c\uac00 \uc544\ub2d9\ub2c8\ub2e4. \uc774 \uc6a9\uc5b4\ub294 SQL \ud45c\uc900 \uc5b8\uc5b4\uc758 \uc77c\ubd80\uac00 \uc544\ub2c8\uba70, SQL\uc758 \uc8fc\uc694 \uae30\ub2a5\uc73c\ub85c \uac04\uc8fc\ub418\uc9c0 \uc54a\uc2b5\ub2c8\ub2e4.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\ub370\uc774\ud130 \uc81c\uc5b4 \uc5b8\uc5b4(DCL) \uc911 <code>GRANT<\/code> \uba85\ub839\uc5b4\uc5d0 \ub300\ud55c \uc124\uba85\uc73c\ub85c \uc633\uc740 \uac83\uc740 <strong>\uc0ac\uc6a9\uc790\uc5d0\uac8c \ud2b9\uc815 \uc791\uc5c5\uc744 \uc218\ud589\ud560 \uad8c\ud55c\uc744 \ubd80\uc5ec\ud55c\ub2e4<\/strong> \uc785\ub2c8\ub2e4.<\/p>\n\n\n\n<p><code>GRANT<\/code> \uba85\ub839\uc740 \ub370\uc774\ud130\ubca0\uc774\uc2a4 \uc2dc\uc2a4\ud15c\uc5d0\uc11c \ub2e4\ub978 \uc0ac\uc6a9\uc790\uc5d0\uac8c \ud2b9\uc815 \ub370\uc774\ud130\ubca0\uc774\uc2a4 \uac1d\uccb4(\uc608: \ud14c\uc774\ube14, \ubdf0 \ub4f1)\uc5d0 \ub300\ud55c \uc811\uadfc\uc774\ub098 \uc870\uc791 \uad8c\ud55c\uc744 \ubd80\uc5ec\ud560 \ub54c \uc0ac\uc6a9\ub429\ub2c8\ub2e4. \uc608\ub97c \ub4e4\uc5b4, \ud2b9\uc815 \uc0ac\uc6a9\uc790\uac00 \ud2b9\uc815 \ud14c\uc774\ube14\uc5d0\uc11c \ub370\uc774\ud130\ub97c \uc870\ud68c\ud558\uac70\ub098 \uc218\uc815\ud560 \uc218 \uc788\ub3c4\ub85d \ud560 \ub54c <code>GRANT<\/code> \uba85\ub839\uc744 \uc0ac\uc6a9\ud569\ub2c8\ub2e4.<\/p>\n\n\n\n<p>\ub2e4\ub978 \uc120\ud0dd\uc9c0\uc5d0 \ub300\ud55c \uc124\uba85:<\/p>\n\n\n\n<ul>\n<li>&#8220;\uc0ac\uc6a9\uc790\ub85c\ubd80\ud130 \ud2b9\uc815 \uc791\uc5c5 \uc218\ud589 \uad8c\ud55c\uc744 \uc81c\uac70\ud55c\ub2e4.&#8221;: \uc774\ub294 <code>REVOKE<\/code> \uba85\ub839\uc5b4\uc758 \uae30\ub2a5\uc785\ub2c8\ub2e4.<\/li>\n\n\n\n<li>&#8220;\ub2e4\ub978 \uc0ac\uc6a9\uc790\uc5d0\uac8c \ub3d9\uc77c\ud55c \uad8c\ud55c\uc744 \uc804\ub2ec\ud560 \ub54c \uc0ac\uc6a9\ud55c\ub2e4.&#8221;: \uc774\ub294 <code>GRANT<\/code>\uc758 \uc77c\ubd80 \uc635\uc158\uc744 \ud1b5\ud574 \uac00\ub2a5\ud560 \uc218 \uc788\uc9c0\ub9cc, <code>GRANT<\/code> \uba85\ub839\uc758 \uc8fc \uae30\ub2a5\uc740 \uc544\ub2d9\ub2c8\ub2e4.<\/li>\n\n\n\n<li>&#8220;\ubd80\uc5ec\ub41c \uad8c\ud55c \uc911 \uc77c\ubd80\ub97c \uc81c\ud55c\ud560 \ub54c \uc0ac\uc6a9\ud55c\ub2e4.&#8221;: \uc774\ub294 <code>GRANT<\/code>\uac00 \uc544\ub2cc <code>REVOKE<\/code> \uba85\ub839\uc5b4\uc758 \uae30\ub2a5\uc785\ub2c8\ub2e4.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\ud14c\uc774\ube14 \uc0dd\uc131 \uc2dc \uceec\ub7fc(\uc18d\uc131)\uc5d0 \uac12\uc774 \ud56d\uc0c1 \uc874\uc7ac\ud558\ub3c4\ub85d \uc124\uc815\ud558\ub294 \uba85\ub839\uc5b4\ub294 <strong>NOT NULL<\/strong> \uc785\ub2c8\ub2e4.<\/p>\n\n\n\n<p><code>NOT NULL<\/code> \uc81c\uc57d \uc870\uac74\uc740 \ud574\ub2f9 \uceec\ub7fc\uc5d0 \ubc18\ub4dc\uc2dc \uac12\uc774 \uc788\uc5b4\uc57c \ud558\uba70, NULL(\uac12\uc774 \uc5c6\uc74c\uc744 \ub098\ud0c0\ub0b4\ub294 \ud2b9\uc218\ud55c \ub9c8\ucee4)\uc744 \ud5c8\uc6a9\ud558\uc9c0 \uc54a\ub294\ub2e4\ub294 \uac83\uc744 \uc758\ubbf8\ud569\ub2c8\ub2e4. \uc774 \uc81c\uc57d \uc870\uac74\uc744 \uc0ac\uc6a9\ud558\uc5ec \ub370\uc774\ud130 \ubb34\uacb0\uc131\uc744 \ubcf4\uc7a5\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4. \uc608\ub97c \ub4e4\uc5b4, \uc0ac\uc6a9\uc790\uc758 \uc774\ub984\uc774\ub098 \uc774\uba54\uc77c \uc8fc\uc18c\uc640 \uac19\uc774 \ud56d\uc0c1 \uc785\ub825\ub418\uc5b4\uc57c \ud558\ub294 \ud544\ub4dc\uc5d0 <code>NOT NULL<\/code> \uc81c\uc57d \uc870\uac74\uc744 \uc801\uc6a9\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4.<\/p>\n\n\n\n<p>\ub2e4\ub978 \uc635\uc158\ub4e4\uc758 \uc758\ubbf8\ub294 \ub2e4\uc74c\uacfc \uac19\uc2b5\ub2c8\ub2e4:<\/p>\n\n\n\n<ul>\n<li><strong>NULL<\/strong>: \uc774\ub294 \uceec\ub7fc\uc774 NULL \uac12\uc744 \uac00\uc9c8 \uc218 \uc788\uc74c\uc744 \uc758\ubbf8\ud569\ub2c8\ub2e4.<\/li>\n\n\n\n<li><strong>IN NULL<\/strong>\uacfc <strong>IS NULL<\/strong>: \uc774\ub4e4\uc740 SQL\uc758 \uc720\ud6a8\ud55c \ubb38\ubc95\uc774 \uc544\ub2d9\ub2c8\ub2e4.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\ud14c\uc774\ube14 \uc0dd\uc131 \uc2dc \uceec\ub7fc(\uc18d\uc131)\uc5d0 \uc911\ubcf5\ub41c \uac12\uc744 \ud5c8\uc6a9\ud558\uc9c0 \uc54a\ub3c4\ub85d \uc124\uc815\ud558\ub294 \uba85\ub839\uc5b4\ub294 <strong>UNIQUE<\/strong>\uc640 <strong>PRIMARY KEY<\/strong> \uc785\ub2c8\ub2e4.<\/p>\n\n\n\n<ol>\n<li><strong>UNIQUE<\/strong>: \uc774 \uc81c\uc57d \uc870\uac74\uc740 \ud2b9\uc815 \uceec\ub7fc\uc5d0 \ub300\ud574 \uc911\ubcf5\ub41c \uac12\uc774 \uc5c6\uc5b4\uc57c \ud568\uc744 \ub098\ud0c0\ub0c5\ub2c8\ub2e4. \ud55c \ud14c\uc774\ube14 \ub0b4\uc5d0\uc11c \uc5ec\ub7ec \uac1c\uc758 UNIQUE \uc81c\uc57d \uc870\uac74\uc744 \uc124\uc815\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4.<\/li>\n\n\n\n<li><strong>PRIMARY KEY<\/strong>: \uc774 \uc81c\uc57d \uc870\uac74\uc740 \ud14c\uc774\ube14 \ub0b4\uc758 \uac01 \ud589\uc744 \uace0\uc720\ud558\uac8c \uc2dd\ubcc4\ud558\ub294 \ub370 \uc0ac\uc6a9\ub429\ub2c8\ub2e4. PRIMARY KEY\ub85c \uc9c0\uc815\ub41c \uceec\ub7fc\uc740 \uc790\ub3d9\uc73c\ub85c UNIQUE \uc81c\uc57d \uc870\uac74\uc744 \uac16\uac8c \ub418\uba70, NULL \uac12\uc744 \ud5c8\uc6a9\ud558\uc9c0 \uc54a\uc2b5\ub2c8\ub2e4.<\/li>\n<\/ol>\n\n\n\n<p>\ub2e4\ub978 \uc635\uc158\ub4e4\uc758 \uc758\ubbf8\ub294 \ub2e4\uc74c\uacfc \uac19\uc2b5\ub2c8\ub2e4:<\/p>\n\n\n\n<ul>\n<li><strong>DEFAULT False<\/strong>: \uc774\ub294 \uceec\ub7fc\uc758 \uae30\ubcf8\uac12\uc744 False\ub85c \uc124\uc815\ud558\ub294 \uac83\uc744 \uc758\ubbf8\ud569\ub2c8\ub2e4. \uc911\ubcf5\uc744 \uc81c\uc5b4\ud558\ub294 \uae30\ub2a5\uc740 \uc5c6\uc2b5\ub2c8\ub2e4.<\/li>\n\n\n\n<li><strong>AUTO_INCREMENT<\/strong>: \uc774\ub294 \uc8fc\ub85c \uc22b\uc790 \ud615\ud0dc\uc758 \uceec\ub7fc\uc5d0 \uc0ac\uc6a9\ub418\uc5b4, \uc0c8\ub85c\uc6b4 \ud589\uc774 \ucd94\uac00\ub420 \ub54c\ub9c8\ub2e4 \uc790\ub3d9\uc73c\ub85c \uac12\uc744 \uc99d\uac00\uc2dc\ud0a4\ub294 \uae30\ub2a5\uc785\ub2c8\ub2e4. \uc790\uccb4\uc801\uc73c\ub85c \uc911\ubcf5\uc744 \ubc29\uc9c0\ud558\uc9c0\ub294 \uc54a\uc9c0\ub9cc, \uc8fc\ub85c PRIMARY KEY\uc640 \ud568\uaed8 \uc0ac\uc6a9\ub418\uc5b4 \uc911\ubcf5\uc744 \ubc29\uc9c0\ud558\ub294 \ub370 \uae30\uc5ec\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4.<\/li>\n<\/ul>\n\n\n\n<p>\uc544\ub798\uc5d0\ub294 <code>UNIQUE<\/code>\uc640 <code>PRIMARY KEY<\/code> \uc81c\uc57d \uc870\uac74\uc744 \uc0ac\uc6a9\ud55c SQL \uc2a4\ud06c\ub9bd\ud2b8 \uc608\uc81c\ub97c \uc81c\uacf5\ud558\uaca0\uc2b5\ub2c8\ub2e4. \uc774 \uc608\uc81c\uc5d0\uc11c\ub294 \uc0ac\uc6a9\uc790 \uc815\ubcf4\ub97c \uc800\uc7a5\ud558\ub294 \ud14c\uc774\ube14\uc744 \uc0dd\uc131\ud558\uace0, <code>UNIQUE<\/code>\uc640 <code>PRIMARY KEY<\/code> \uc81c\uc57d \uc870\uac74\uc744 \uc801\uc6a9\ud569\ub2c8\ub2e4.<\/p>\n\n\n\n<div class=\"wp-block-kevinbatdorf-code-block-pro\" data-code-block-pro-font-family=\"Code-Pro-JetBrains-Mono\" style=\"font-size:.875rem;font-family:Code-Pro-JetBrains-Mono,ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;line-height:1.25rem;--cbp-tab-width:2;tab-size:var(--cbp-tab-width, 2)\"><span style=\"display:block;padding:16px 0 0 16px;margin-bottom:-1px;width:100%;text-align:left;background-color:#0F111A\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"54\" height=\"14\" viewBox=\"0 0 54 14\"><g fill=\"none\" fill-rule=\"evenodd\" transform=\"translate(1 1)\"><circle cx=\"6\" cy=\"6\" r=\"6\" fill=\"#FF5F56\" stroke=\"#E0443E\" stroke-width=\".5\"><\/circle><circle cx=\"26\" cy=\"6\" r=\"6\" fill=\"#FFBD2E\" stroke=\"#DEA123\" stroke-width=\".5\"><\/circle><circle cx=\"46\" cy=\"6\" r=\"6\" fill=\"#27C93F\" stroke=\"#1AAB29\" stroke-width=\".5\"><\/circle><\/g><\/svg><\/span><span role=\"button\" tabindex=\"0\" data-code=\"CREATE TABLE Users (\n    UserID INT AUTO_INCREMENT PRIMARY KEY,\n    Username VARCHAR(50) NOT NULL UNIQUE,\n    Email VARCHAR(100) NOT NULL UNIQUE,\n    Password VARCHAR(50) NOT NULL,\n    JoinDate DATE NOT NULL\n);\n\nINSERT INTO Users (Username, Email, Password, JoinDate) \nVALUES ('user1', 'user1@example.com', 'pass123', '2023-01-01');\n\nINSERT INTO Users (Username, Email, Password, JoinDate) \nVALUES ('user2', 'user2@example.com', 'pass456', '2023-02-01');\" style=\"color:#babed8;display:none\" aria-label=\"Copy\" class=\"code-block-pro-copy-button\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" style=\"width:24px;height:24px\" fill=\"none\" viewBox=\"0 0 24 24\" stroke=\"currentColor\" stroke-width=\"2\"><path class=\"with-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4\"><\/path><path class=\"without-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2\"><\/path><\/svg><\/span><pre class=\"shiki material-theme-ocean\" style=\"background-color: #0F111A\" tabindex=\"0\"><code><span class=\"line\"><span style=\"color: #F78C6C\">CREATE<\/span><span style=\"color: #BABED8\"> <\/span><span style=\"color: #F78C6C\">TABLE<\/span><span style=\"color: #BABED8\"> <\/span><span style=\"color: #82AAFF\">Users<\/span><span style=\"color: #BABED8\"> (<\/span><\/span>\n<span class=\"line\"><span style=\"color: #BABED8\">    UserID <\/span><span style=\"color: #C792EA\">INT<\/span><span style=\"color: #BABED8\"> AUTO_INCREMENT <\/span><span style=\"color: #C792EA\">PRIMARY KEY<\/span><span style=\"color: #BABED8\">,<\/span><\/span>\n<span class=\"line\"><span style=\"color: #BABED8\">    Username <\/span><span style=\"color: #C792EA\">VARCHAR<\/span><span style=\"color: #BABED8\">(<\/span><span style=\"color: #F78C6C\">50<\/span><span style=\"color: #BABED8\">) <\/span><span style=\"color: #F78C6C\">NOT NULL<\/span><span style=\"color: #BABED8\"> <\/span><span style=\"color: #F78C6C\">UNIQUE<\/span><span style=\"color: #BABED8\">,<\/span><\/span>\n<span class=\"line\"><span style=\"color: #BABED8\">    Email <\/span><span style=\"color: #C792EA\">VARCHAR<\/span><span style=\"color: #BABED8\">(<\/span><span style=\"color: #F78C6C\">100<\/span><span style=\"color: #BABED8\">) <\/span><span style=\"color: #F78C6C\">NOT NULL<\/span><span style=\"color: #BABED8\"> <\/span><span style=\"color: #F78C6C\">UNIQUE<\/span><span style=\"color: #BABED8\">,<\/span><\/span>\n<span class=\"line\"><span style=\"color: #BABED8\">    <\/span><span style=\"color: #F78C6C\">Password<\/span><span style=\"color: #BABED8\"> <\/span><span style=\"color: #C792EA\">VARCHAR<\/span><span style=\"color: #BABED8\">(<\/span><span style=\"color: #F78C6C\">50<\/span><span style=\"color: #BABED8\">) <\/span><span style=\"color: #F78C6C\">NOT NULL<\/span><span style=\"color: #BABED8\">,<\/span><\/span>\n<span class=\"line\"><span style=\"color: #BABED8\">    JoinDate <\/span><span style=\"color: #C792EA\">DATE<\/span><span style=\"color: #BABED8\"> <\/span><span style=\"color: #F78C6C\">NOT NULL<\/span><\/span>\n<span class=\"line\"><span style=\"color: #BABED8\">);<\/span><\/span>\n<span class=\"line\"><\/span>\n<span class=\"line\"><span style=\"color: #F78C6C\">INSERT INTO<\/span><span style=\"color: #BABED8\"> Users (Username, Email, <\/span><span style=\"color: #F78C6C\">Password<\/span><span style=\"color: #BABED8\">, JoinDate) <\/span><\/span>\n<span class=\"line\"><span style=\"color: #F78C6C\">VALUES<\/span><span style=\"color: #BABED8\"> (<\/span><span style=\"color: #89DDFF\">&#39;<\/span><span style=\"color: #C3E88D\">user1<\/span><span style=\"color: #89DDFF\">&#39;<\/span><span style=\"color: #BABED8\">, <\/span><span style=\"color: #89DDFF\">&#39;<\/span><span style=\"color: #C3E88D\">user1@example.com<\/span><span style=\"color: #89DDFF\">&#39;<\/span><span style=\"color: #BABED8\">, <\/span><span style=\"color: #89DDFF\">&#39;<\/span><span style=\"color: #C3E88D\">pass123<\/span><span style=\"color: #89DDFF\">&#39;<\/span><span style=\"color: #BABED8\">, <\/span><span style=\"color: #89DDFF\">&#39;<\/span><span style=\"color: #C3E88D\">2023-01-01<\/span><span style=\"color: #89DDFF\">&#39;<\/span><span style=\"color: #BABED8\">);<\/span><\/span>\n<span class=\"line\"><\/span>\n<span class=\"line\"><span style=\"color: #F78C6C\">INSERT INTO<\/span><span style=\"color: #BABED8\"> Users (Username, Email, <\/span><span style=\"color: #F78C6C\">Password<\/span><span style=\"color: #BABED8\">, JoinDate) <\/span><\/span>\n<span class=\"line\"><span style=\"color: #F78C6C\">VALUES<\/span><span style=\"color: #BABED8\"> (<\/span><span style=\"color: #89DDFF\">&#39;<\/span><span style=\"color: #C3E88D\">user2<\/span><span style=\"color: #89DDFF\">&#39;<\/span><span style=\"color: #BABED8\">, <\/span><span style=\"color: #89DDFF\">&#39;<\/span><span style=\"color: #C3E88D\">user2@example.com<\/span><span style=\"color: #89DDFF\">&#39;<\/span><span style=\"color: #BABED8\">, <\/span><span style=\"color: #89DDFF\">&#39;<\/span><span style=\"color: #C3E88D\">pass456<\/span><span style=\"color: #89DDFF\">&#39;<\/span><span style=\"color: #BABED8\">, <\/span><span style=\"color: #89DDFF\">&#39;<\/span><span style=\"color: #C3E88D\">2023-02-01<\/span><span style=\"color: #89DDFF\">&#39;<\/span><span style=\"color: #BABED8\">);<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n<p>\uc774 \uc2a4\ud06c\ub9bd\ud2b8\ub294 \ub2e4\uc74c\uacfc \uac19\uc740 \uc791\uc5c5\uc744 \uc218\ud589\ud569\ub2c8\ub2e4:<\/p>\n\n\n\n<ul>\n<li><code>Users<\/code>\ub77c\ub294 \uc774\ub984\uc758 \ud14c\uc774\ube14\uc744 \uc0dd\uc131\ud569\ub2c8\ub2e4. \uc774 \ud14c\uc774\ube14\uc5d0\ub294 \uc0ac\uc6a9\uc790 ID, \uc0ac\uc6a9\uc790\uba85, \uc774\uba54\uc77c, \ube44\ubc00\ubc88\ud638, \uac00\uc785 \ub0a0\uc9dc\uac00 \ud3ec\ud568\ub429\ub2c8\ub2e4.<\/li>\n\n\n\n<li><code>UserID<\/code>\ub294 \uc790\ub3d9 \uc99d\uac00\ud558\ub294 \uae30\ubcf8 \ud0a4(<code>PRIMARY KEY<\/code>)\ub85c \uc124\uc815\ub418\uc5b4 \uc788\uc5b4 \uac01 \uc0ac\uc6a9\uc790\ub97c \uace0\uc720\ud558\uac8c \uc2dd\ubcc4\ud569\ub2c8\ub2e4.<\/li>\n\n\n\n<li><code>Username<\/code>\uacfc <code>Email<\/code> \ud544\ub4dc\ub294 <code>UNIQUE<\/code> \uc81c\uc57d \uc870\uac74\uc744 \uac00\uc9d1\ub2c8\ub2e4. \uc774\ub294 \ubaa8\ub4e0 \uc0ac\uc6a9\uc790\uba85\uacfc \uc774\uba54\uc77c \uc8fc\uc18c\uac00 \ud14c\uc774\ube14 \ub0b4\uc5d0\uc11c \uc720\uc77c\ud574\uc57c \ud568\uc744 \uc758\ubbf8\ud569\ub2c8\ub2e4.<\/li>\n\n\n\n<li><code>Password<\/code>\uc640 <code>JoinDate<\/code>\ub294 \ud544\uc218 \ud544\ub4dc\uc785\ub2c8\ub2e4(<code>NOT NULL<\/code>).<\/li>\n\n\n\n<li>\ub450 \uba85\uc758 \uc0ac\uc6a9\uc790 (user1\uacfc user2)\uc5d0 \ub300\ud55c \ub808\ucf54\ub4dc\ub97c \ud14c\uc774\ube14\uc5d0 \uc0bd\uc785\ud569\ub2c8\ub2e4.<\/li>\n<\/ul>\n\n\n\n<p>\uc774 \uc2a4\ud06c\ub9bd\ud2b8\ub294 <code>UNIQUE<\/code>\uc640 <code>PRIMARY KEY<\/code> \uc81c\uc57d \uc870\uac74\uc758 \uae30\ubcf8\uc801\uc778 \uc0ac\uc6a9 \ubc29\ubc95\uc744 \ubcf4\uc5ec\uc90d\ub2c8\ub2e4. \uc2e4\uc81c \ub370\uc774\ud130\ubca0\uc774\uc2a4 \uc2dc\uc2a4\ud15c\uc5d0\uc11c \uc2e4\ud589\ud560 \ub54c\ub294 \ub370\uc774\ud130\ubca0\uc774\uc2a4\uc758 \ud2b9\uc815 \uc694\uad6c \uc0ac\ud56d\uc5d0 \ub530\ub77c \uc57d\uac04\uc758 \uc218\uc815\uc774 \ud544\uc694\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\ub370\uc774\ud130\ubca0\uc774\uc2a4\uc758 \uc22b\uc790\ud615 \ub370\uc774\ud130 \ud0c0\uc785\uc774 \uc544\ub2cc \uac83\uc740 <strong>CHAR<\/strong> \uc785\ub2c8\ub2e4.<\/p>\n\n\n\n<ul>\n<li><strong>CHAR<\/strong>: \ubb38\uc790 \ub370\uc774\ud130\ub97c \uc800\uc7a5\ud558\ub294 \ub370 \uc0ac\uc6a9\ub418\ub294 \ub370\uc774\ud130 \ud0c0\uc785\uc785\ub2c8\ub2e4. \uace0\uc815 \uae38\uc774\uc758 \ubb38\uc790\uc5f4\uc744 \uc800\uc7a5\ud569\ub2c8\ub2e4.<\/li>\n<\/ul>\n\n\n\n<p>\ub2e4\ub978 \ub098\uc5f4\ub41c \ud0c0\uc785\ub4e4\uc740 \uc22b\uc790\ud615 \ub370\uc774\ud130 \ud0c0\uc785\uc785\ub2c8\ub2e4:<\/p>\n\n\n\n<ul>\n<li><strong>BIT<\/strong>: \ube44\ud2b8(0 \ub610\ub294 1) \uac12\uc744 \uc800\uc7a5\ud558\ub294 \ub370 \uc0ac\uc6a9\ub418\ub294 \ub370\uc774\ud130 \ud0c0\uc785\uc785\ub2c8\ub2e4.<\/li>\n\n\n\n<li><strong>BIGINT<\/strong>: \ub9e4\uc6b0 \ud070 \uc815\uc218 \uac12\uc744 \uc800\uc7a5\ud558\ub294 \ub370 \uc0ac\uc6a9\ub418\ub294 \ub370\uc774\ud130 \ud0c0\uc785\uc785\ub2c8\ub2e4.<\/li>\n\n\n\n<li><strong>INT<\/strong>: \uc815\uc218 \uac12\uc744 \uc800\uc7a5\ud558\ub294 \ub370 \uc0ac\uc6a9\ub418\ub294 \ud45c\uc900 \uc22b\uc790\ud615 \ub370\uc774\ud130 \ud0c0\uc785\uc785\ub2c8\ub2e4.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>CHAR\uacfc VARCHAR\uc758 \ucc28\uc774\ub85c \uc633\uc740 \uac83\uc740 <strong>\ub370\uc774\ud130\ub97c \ub2f4\uc744 \uc218 \uc788\ub294 \uacf5\uac04\uc774 \uace0\uc815\uc778\uc9c0 \uac00\ubcc0\uc778\uc9c0\uc758 \ucc28\uc774<\/strong> \uc785\ub2c8\ub2e4.<\/p>\n\n\n\n<ul>\n<li><strong>CHAR<\/strong>: \uace0\uc815 \uae38\uc774\uc758 \ubb38\uc790\uc5f4\uc744 \uc800\uc7a5\ud569\ub2c8\ub2e4. \uc815\ud574\uc9c4 \uae38\uc774\ub85c \uc124\uc815\ub418\uba70, \uc800\uc7a5\ub41c \ubb38\uc790\uc5f4\uc774 \uc774 \uae38\uc774\ubcf4\ub2e4 \uc9e7\uc744 \uacbd\uc6b0 \ub098\uba38\uc9c0 \uacf5\uac04\uc740 \uacf5\ubc31\uc73c\ub85c \ucc44\uc6cc\uc9d1\ub2c8\ub2e4. \uc608\ub97c \ub4e4\uc5b4, CHAR(5)\ub85c \uc815\uc758\ub41c \ud544\ub4dc\uc5d0 &#8216;Hi&#8217;\ub97c \uc800\uc7a5\ud558\uba74, \ub098\uba38\uc9c0 \uacf5\uac04\uc740 \uacf5\ubc31\uc73c\ub85c \ucc44\uc6cc\uc838 &#8216;Hi &#8216;\ub85c \uc800\uc7a5\ub429\ub2c8\ub2e4.<\/li>\n\n\n\n<li><strong>VARCHAR<\/strong>: \uac00\ubcc0 \uae38\uc774\uc758 \ubb38\uc790\uc5f4\uc744 \uc800\uc7a5\ud569\ub2c8\ub2e4. \uc124\uc815\ub41c \ucd5c\ub300 \uae38\uc774\uae4c\uc9c0 \ubb38\uc790\uc5f4\uc744 \uc800\uc7a5\ud560 \uc218 \uc788\uc73c\uba70, \uc2e4\uc81c \uc0ac\uc6a9\ud558\ub294 \ubb38\uc790\uc5f4 \uae38\uc774\ub9cc\ud07c\ub9cc \uacf5\uac04\uc744 \ucc28\uc9c0\ud569\ub2c8\ub2e4. \uc608\ub97c \ub4e4\uc5b4, VARCHAR(5)\ub85c \uc815\uc758\ub41c \ud544\ub4dc\uc5d0 &#8216;Hi&#8217;\ub97c \uc800\uc7a5\ud558\uba74, \uc2e4\uc81c\ub85c &#8216;Hi&#8217;\ub9cc \uc800\uc7a5\ub418\uba70 \ucd94\uac00 \uacf5\uac04\uc740 \uc0ac\uc6a9\ub418\uc9c0 \uc54a\uc2b5\ub2c8\ub2e4.<\/li>\n<\/ul>\n\n\n\n<p>\ub2e4\ub978 \uc635\uc158\ub4e4\uc5d0 \ub300\ud55c \uc124\uba85:<\/p>\n\n\n\n<ul>\n<li>&#8220;\ubb38\uc790\uc5f4 \uac12\uc744 \uc815\uc218\ub85c \ud45c\ud604\ud560 \uc218 \uc788\ub294\uc9c0\uc758 \ucc28\uc774&#8221;\uc640 &#8220;\uc800\uc7a5\ud560 \uc218 \uc788\ub294 \ub370\uc774\ud130 \uc885\ub958(\ubb38\uc790, \uc22b\uc790)\uac00 \ub2e4\ub984&#8221;: \uc774 \ub458\uc740 CHAR\uacfc VARCHAR \uc0ac\uc774\uc758 \ucc28\uc774\uc810\uc774 \uc544\ub2d9\ub2c8\ub2e4. \ub458 \ub2e4 \ubb38\uc790 \ub370\uc774\ud130\ub97c \uc800\uc7a5\ud558\uae30 \uc704\ud55c \ud0c0\uc785\uc785\ub2c8\ub2e4.<\/li>\n\n\n\n<li>&#8220;\ud55c\ubc88 \uc785\ub825\ub41c \ub370\uc774\ud130\uc758 \uc218\uc815 \uc5ec\ubd80\uc758 \ucc28\uc774&#8221;: \uc774\uac83\ub3c4 CHAR\uacfc VARCHAR \uc0ac\uc774\uc758 \ucc28\uc774\uc810\uc774 \uc544\ub2d9\ub2c8\ub2e4. \ub458 \ub2e4 \uc218\uc815\uc774 \uac00\ub2a5\ud55c \ub370\uc774\ud130 \ud0c0\uc785\uc785\ub2c8\ub2e4.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\ub370\uc774\ud130\ubca0\uc774\uc2a4 \ub0b4\uc758 \ud2b8\ub79c\uc7ad\uc158\uc744 \uad00\ub9ac\ud558\ub294\ub370 \uc0ac\uc6a9\ub418\ub294 \uc5b8\uc5b4\ub294 <strong>TCL<\/strong>\uc785\ub2c8\ub2e4.<\/p>\n\n\n\n<ul>\n<li><strong>TCL (Transaction Control Language)<\/strong>: \ub370\uc774\ud130\ubca0\uc774\uc2a4\uc5d0\uc11c \ud2b8\ub79c\uc7ad\uc158\uc744 \uad00\ub9ac\ud558\ub294 \ub370 \uc0ac\uc6a9\ub429\ub2c8\ub2e4. \uc8fc\uc694 \uba85\ub839\uc5b4\ub85c\ub294 <code>COMMIT<\/code> (\ud2b8\ub79c\uc7ad\uc158\uc758 \ubcc0\uacbd \uc0ac\ud56d\uc744 \ub370\uc774\ud130\ubca0\uc774\uc2a4\uc5d0 \uc601\uad6c\uc801\uc73c\ub85c \ubc18\uc601), <code>ROLLBACK<\/code> (\ud2b8\ub79c\uc7ad\uc158\uc758 \ubcc0\uacbd \uc0ac\ud56d\uc744 \ucde8\uc18c\ud558\uace0 \uc774\uc804 \uc0c1\ud0dc\ub85c \ub418\ub3cc\ub9bc), <code>SAVEPOINT<\/code> (\ud2b8\ub79c\uc7ad\uc158 \ub0b4 \ud2b9\uc815 \uc9c0\uc810\uc5d0 \ub300\ud55c \ub9c8\ucee4 \uc124\uc815) \ub4f1\uc774 \uc788\uc2b5\ub2c8\ub2e4.<\/li>\n<\/ul>\n\n\n\n<p>\ub2e4\ub978 \uc635\uc158\ub4e4\uc5d0 \ub300\ud55c \uc124\uba85:<\/p>\n\n\n\n<ul>\n<li><strong>DDL (Data Definition Language)<\/strong>: \ub370\uc774\ud130 \uad6c\uc870\ub97c \uc815\uc758\ud558\ub294 \ub370 \uc0ac\uc6a9\ub429\ub2c8\ub2e4 (\uc608: <code>CREATE<\/code>, <code>ALTER<\/code>, <code>DROP<\/code>).<\/li>\n\n\n\n<li><strong>DML (Data Manipulation Language)<\/strong>: \ub370\uc774\ud130\ub97c \uc870\uc791\ud558\ub294 \ub370 \uc0ac\uc6a9\ub429\ub2c8\ub2e4 (\uc608: <code>SELECT<\/code>, <code>INSERT<\/code>, <code>UPDATE<\/code>, <code>DELETE<\/code>).<\/li>\n\n\n\n<li><strong>DCL (Data Control Language)<\/strong>: \ub370\uc774\ud130\ubca0\uc774\uc2a4\uc758 \ubcf4\uc548\uacfc \uc811\uadfc \uad8c\ud55c\uc744 \uad00\ub9ac\ud558\ub294 \ub370 \uc0ac\uc6a9\ub429\ub2c8\ub2e4 (\uc608: <code>GRANT<\/code>, <code>REVOKE<\/code>).<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>\uce7c\ub7fc\uc5d0 \uc800\uc7a5\ub420 \uc218 \uc788\ub294 \uac12\uc758 \ubc94\uc704\ub098 \uc870\uac74\uc744 \uc9c0\uc815\ud558\ub294 \uba85\ub839\uc5b4\ub294 <strong>CHECK<\/strong> \uc785\ub2c8\ub2e4.<\/p>\n\n\n\n<ul>\n<li><strong>CHECK<\/strong>: \ud14c\uc774\ube14\uc758 \ud2b9\uc815 \uce7c\ub7fc\uc5d0 \ub300\ud574 \uc800\uc7a5\ub420 \uc218 \uc788\ub294 \uac12\uc758 \ubc94\uc704\ub098 \uc870\uac74\uc744 \uc9c0\uc815\ud558\ub294 \ub370 \uc0ac\uc6a9\ub429\ub2c8\ub2e4. \uc608\ub97c \ub4e4\uc5b4, \ud2b9\uc815 \uce7c\ub7fc\uc758 \uac12\uc774 \ud2b9\uc815 \ubc94\uc704 \ub0b4\uc5d0 \uc788\uac70\ub098 \ud2b9\uc815 \uc870\uac74\uc744 \ub9cc\uc871\ud574\uc57c \ud560 \uacbd\uc6b0\uc5d0 \uc0ac\uc6a9\ud569\ub2c8\ub2e4.<\/li>\n<\/ul>\n\n\n\n<p>\ub2e4\ub978 \uc635\uc158\ub4e4\uc5d0 \ub300\ud55c \uc124\uba85:<\/p>\n\n\n\n<ul>\n<li><strong>ON<\/strong>: \uc8fc\ub85c \uc81c\uc57d \uc870\uac74\uc774\ub098 \ud2b8\ub9ac\uac70\ub97c \ud2b9\uc815 \ud14c\uc774\ube14\uc774\ub098 \ubdf0\uc5d0 \uc5f0\uacb0\ud560 \ub54c \uc0ac\uc6a9\ub429\ub2c8\ub2e4.<\/li>\n\n\n\n<li><strong>WHERE<\/strong>: SELECT, UPDATE, DELETE \ub4f1\uc758 \uba85\ub839\uc5b4\uc640 \ud568\uaed8 \uc0ac\uc6a9\ub418\uc5b4, \ud2b9\uc815 \uc870\uac74\uc744 \ub9cc\uc871\ud558\ub294 \ub808\ucf54\ub4dc\uc5d0 \ub300\ud55c \uc791\uc5c5\uc744 \uc218\ud589\ud569\ub2c8\ub2e4.<\/li>\n\n\n\n<li><strong>IN<\/strong>: \uc8fc\ub85c WHERE \uc808 \ub0b4\uc5d0\uc11c \uc0ac\uc6a9\ub418\uba70, \ud2b9\uc815 \uce7c\ub7fc\uc758 \uac12\uc774 \uc9c0\uc815\ub41c \ubaa9\ub85d\uc5d0 \uc788\ub294\uc9c0\ub97c \uac80\uc0ac\ud569\ub2c8\ub2e4.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>SQL \uc815\ub9ac \ub178\ud2b8<\/p>\n","protected":false},"author":1,"featured_media":1656,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_uf_show_specific_survey":0,"_uf_disable_surveys":false,"footnotes":""},"categories":[1],"tags":[137,118,132,134,135,138,136,117,129,130,126,124,123,119,120,121,125,122,131,128,127,133],"_links":{"self":[{"href":"https:\/\/dohokin.com\/index.php?rest_route=\/wp\/v2\/posts\/1650"}],"collection":[{"href":"https:\/\/dohokin.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/dohokin.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/dohokin.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/dohokin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1650"}],"version-history":[{"count":2,"href":"https:\/\/dohokin.com\/index.php?rest_route=\/wp\/v2\/posts\/1650\/revisions"}],"predecessor-version":[{"id":1657,"href":"https:\/\/dohokin.com\/index.php?rest_route=\/wp\/v2\/posts\/1650\/revisions\/1657"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/dohokin.com\/index.php?rest_route=\/wp\/v2\/media\/1656"}],"wp:attachment":[{"href":"https:\/\/dohokin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1650"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/dohokin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1650"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/dohokin.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1650"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}