{"id":487,"date":"2026-05-17T07:02:06","date_gmt":"2026-05-16T23:02:06","guid":{"rendered":"https:\/\/junai.ai\/blog\/pg-first-crud-5\/"},"modified":"2026-05-17T07:02:06","modified_gmt":"2026-05-16T23:02:06","slug":"pg-first-crud-5","status":"publish","type":"post","link":"https:\/\/junai.ai\/blog\/pg-first-crud-5\/","title":{"rendered":"SQL \uccab CRUD \u2014 4\uac00\uc9c0 \uae30\ubcf8 \ub3d9\uc0ac (\uc785\ubb38 5\ud3b8)"},"content":{"rendered":"\n<!-- WordPress REST API \ubc1c\ud589\uc6a9 HTML (\uc790\ub3d9 \uc0dd\uc131) -->\n<!-- WP-FEATURED-MEDIA-ID: 268 -->\n<div style=\"max-width:800px;margin:0 auto;\">\n<style>\n:root{--color-primary:#336791;--color-accent:#60a5fa;--color-bg:#fafafa;--color-bg-card:#ffffff;--color-text:#1e293b;--color-text-muted:#64748b;--hero-start:#0f172a;--hero-end:#336791;--font-body:-apple-system,BlinkMacSystemFont,'Apple SD Gothic Neo','Noto Sans 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22px;border-radius:10px;margin-top:24px;font-size:14.5px;color:var(--color-text-muted);}\n.series-nav strong{color:var(--color-primary);}\n@media (max-width:480px){.hero{padding:52px 18px 44px;}.hero h1{font-size:26px;}.hero p.sub{font-size:15px;}article{padding:28px 18px;border-radius:10px;}h2{font-size:22px;}h3{font-size:18px;}body{font-size:16px;}pre{font-size:13px;padding:14px 16px;}}\n@media (max-width:560px){.tablewrap table,.tablewrap thead,.tablewrap tbody,.tablewrap tr,.tablewrap th,.tablewrap td{display:block;width:auto;}.tablewrap thead{display:none;}.tablewrap tr{margin:0 0 14px;border:1px solid #e2e8f0;border-radius:10px;overflow:hidden;}.tablewrap td{border:none;border-bottom:1px solid #f1f5f9;padding:9px 14px;}.tablewrap td:first-child{background:#eff6ff;font-weight:800;font-size:15.5px;}.tablewrap td:last-child{border-bottom:none;}.tablewrap td[data-label]::before{content:attr(data-label) \" \u2014 \";font-weight:700;color:var(--color-primary);}}\n<\/style>\n<header class=\"hero\">\n  <span class=\"badge\">PostgreSQL \uad50\uc7ac \u00b7 5\ud3b8 \/ 24\ud3b8<\/span>\n  <h1>INSERT\u00b7SELECT\u00b7UPDATE\u00b7DELETE \u2014 \uccab CRUD<\/h1>\n  <p class=\"sub\">\ub370\uc774\ud130\ub97c \ub123\uace0\u00b7\uc77d\uace0\u00b7\ubc14\uafb8\uace0\u00b7\uc9c0\uc6b0\ub294 4\uc885 + UPDATE\/DELETE \uc758 \ud55c \uac00\uc9c0 \uc548\uc804 \uaddc\uce59.<\/p>\n  <div class=\"meta\"><span>\uc785\ubb38<\/span><span>\uc77d\ub294 \uc2dc\uac04 7\ubd84<\/span><span>2026-05-17<\/span><\/div>\n  <img decoding=\"async\" src=\"https:\/\/junai.ai\/blog\/wp-content\/uploads\/2026\/05\/hero-48.jpg\" alt=\"INSERT\/SELECT\/UPDATE\/DELETE 4\uac1c\uc758 SQL \ud0a4\uc6cc\ub4dc\uac00 \uc0c9\uc0c1\uc73c\ub85c \uac15\uc870\ub41c \uc77c\ub7ec\uc2a4\ud2b8\">\n<\/header>\n\n<div class=\"container\">\n<article>\n\n<p>SQL \uc758 90% \ub294 4\uac00\uc9c0 \ub3d9\uc0ac\ub85c \ub05d\ub0a9\ub2c8\ub2e4 \u2014 <strong>INSERT(\ub123\uae30)\u00b7SELECT(\uc77d\uae30)\u00b7UPDATE(\ubc14\uafb8\uae30)\u00b7DELETE(\uc9c0\uc6b0\uae30)<\/strong>. \ud569\uccd0\uc11c CRUD(Create\u00b7Read\u00b7Update\u00b7Delete). 5\ud3b8\uc740 \uc785\ubb38 \ud30c\ud2b8\uc758 \ub9c8\uc9c0\ub9c9\uc73c\ub85c, \uc774 4\uac00\uc9c0\ub97c \ud55c \ud654\uba74\uc5d0 \uc775\ud799\ub2c8\ub2e4.<\/p>\n\n<p>\uc2e4\uc2b5 \ud14c\uc774\ube14\uc740 3\ud3b8\uc758 <code>users<\/code> \ub97c \uadf8\ub300\ub85c \uc501\ub2c8\ub2e4.<\/p>\n\n<pre><code>CREATE TABLE users (\n  id     BIGSERIAL PRIMARY KEY,\n  name   TEXT NOT NULL,\n  email  TEXT UNIQUE,\n  age    INTEGER CHECK (age &gt;= 0),\n  active BOOLEAN NOT NULL DEFAULT TRUE,\n  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()\n);<\/code><\/pre>\n\n<h2>INSERT \u2014 \ub370\uc774\ud130 \ub123\uae30<\/h2>\n\n<pre><code>-- \ud55c \ud589\nINSERT INTO users (name, email, age)\nVALUES ('\uc900\uc131', 'jspark1st@gmail.com', 39);\n\n-- \uc5ec\ub7ec \ud589 (\ud55c \ubc88\uc5d0)\nINSERT INTO users (name, email, age) VALUES\n  ('\ud64d\uae38\ub3d9', 'hong@x.com',  30),\n  ('\uae40\uc790\ubc14', 'kim@x.com',   25),\n  ('\ubc15\ud30c\uc774', 'park@x.com',  45);\n\n-- \uacb0\uacfc \ubc1b\uc544\uc624\uae30 (INSERT ... RETURNING)\nINSERT INTO users (name, email, age)\nVALUES ('\uc774\ud0c0\uc785', 'lee@x.com', 28)\nRETURNING id, created_at;\n--  id |          created_at\n-- ----+-------------------------------\n--   5 | 2026-05-17 00:25:00.123+09<\/code><\/pre>\n\n<div class=\"databox\">\n  <p><strong>RETURNING \uc758 \uac00\uce58.<\/strong> \ubc29\uae08 \ub9cc\ub4e0 \ud589\uc758 \uc790\ub3d9 \uc0dd\uc131\ub41c PK(id), \uc2dc\uac01(created_at) \uc744 \uc989\uc2dc \ubc1b\uc2b5\ub2c8\ub2e4. \uc560\ud50c\ub9ac\ucf00\uc774\uc158 \ucf54\ub4dc\uc5d0\uc11c &#8220;INSERT \ud55c \ub2e4\uc74c \ub2e4\uc2dc SELECT&#8221; \uac19\uc740 \ub450 \ubc88 \uc655\ubcf5\uc744 \ud55c \ubc88\uc73c\ub85c \uc904\uc785\ub2c8\ub2e4. UPDATE\u00b7DELETE \uc5d0\ub3c4 \ub3d9\uc77c\ud558\uac8c \ubd99\uc77c \uc218 \uc788\uc5b4\uc694.<\/p>\n<\/div>\n\n<h2>SELECT \u2014 \ub370\uc774\ud130 \uc77d\uae30<\/h2>\n\n<pre><code>-- \uc804\ubd80 (\uc791\uc744 \ub54c\ub9cc, \ubcf4\ud1b5\uc740 \uceec\ub7fc \uc9c0\uc815 \uad8c\uc7a5)\nSELECT * FROM users;\n\n-- \uceec\ub7fc \uc9c0\uc815 + \ubcc4\uce6d\nSELECT id AS user_id, name, age\nFROM   users;\n\n-- WHERE \uc870\uac74\nSELECT name, email\nFROM   users\nWHERE  active = true AND age &gt;= 30;\n\n-- \uc815\ub82c\u00b7\uac2f\uc218 \uc81c\ud55c\nSELECT name, age FROM users\nWHERE  active\nORDER BY age DESC\nLIMIT 5;\n\n-- \ud568\uc218\u00b7\ud45c\ud604\uc2dd\nSELECT name,\n       age + 1                   AS next_age,\n       upper(email)              AS email_upper,\n       extract(year from created_at) AS year_joined\nFROM users;<\/code><\/pre>\n\n<p><code>SELECT *<\/code> \ub294 \ud559\uc2b5\u00b7\ub514\ubc84\uadf8\uc6a9\uc73c\ub85c\ub9cc, \uc6b4\uc601 \ucf54\ub4dc\uc5d0\uc11c\ub294 \uac70\uc758 \ud56d\uc0c1 \uceec\ub7fc \uba85\uc2dc. <strong>\uc774\uc720<\/strong>: \uc2a4\ud0a4\ub9c8\uac00 \ubc14\ub00c\uc5b4\ub3c4 \ucf54\ub4dc\uac00 \uc601\ud5a5 \uc548 \ubc1b\uace0, \ub124\ud2b8\uc6cc\ud06c\/\uba54\ubaa8\ub9ac\ub3c4 \uc544\ub08d\ub2c8\ub2e4. WHERE\u00b7ORDER BY\u00b7LIMIT \uc758 \ubcf8\uaca9\uc801\uc778 \uc0ac\uc6a9\ubc95\uc740 6\u00b77\ud3b8\uc5d0\uc11c.<\/p>\n\n<h2>UPDATE \u2014 \ub370\uc774\ud130 \ubc14\uafb8\uae30<\/h2>\n\n<pre><code>-- \ud55c \ud589\nUPDATE users\nSET    age = 40\nWHERE  id = 1;\n\n-- \uc5ec\ub7ec \uceec\ub7fc\nUPDATE users\nSET    age = age + 1,\n       active = true\nWHERE  email = 'lee@x.com';\n\n-- \ud45c\ud604\uc2dd\nUPDATE users\nSET    name = upper(name)\nWHERE  active;\n\n-- RETURNING \uc73c\ub85c \ubcc0\uacbd \uacb0\uacfc \ud655\uc778\nUPDATE users\nSET    age = age + 1\nWHERE  id = 1\nRETURNING id, name, age;<\/code><\/pre>\n\n<h2>DELETE \u2014 \ub370\uc774\ud130 \uc9c0\uc6b0\uae30<\/h2>\n\n<pre><code>-- \ud55c \ud589\nDELETE FROM users WHERE id = 5;\n\n-- \uc870\uac74\uc5d0 \ub9de\ub294 \ubaa8\ub450\nDELETE FROM users WHERE active = false AND created_at &lt; NOW() - INTERVAL '1 year';\n\n-- \uc804\ubd80 (\uc870\uc2ec!)\nDELETE FROM users;\nTRUNCATE users;       -- \ub354 \ube60\ub984, \uc2dc\ud000\uc2a4\ub3c4 \ub9ac\uc14b(RESTART IDENTITY \uc635\uc158)<\/code><\/pre>\n\n<h2>UPDATE\/DELETE \uc758 \ub2e8 \ud558\ub098\uc758 \uc548\uc804 \uaddc\uce59<\/h2>\n\n<div class=\"warnbox\">\n  <p><strong>&#8220;UPDATE \/ DELETE \ub97c \uce60 \ub54c \uba3c\uc800 \uac19\uc740 WHERE \ub85c SELECT \ub97c \uce5c\ub2e4.&#8221;<\/strong><\/p>\n  <p>\uc6b4\uc601 DB \uc5d0\uc11c \uac00\uc7a5 \ud754\ud55c \uc0ac\uace0\uac00 <strong>WHERE \ub97c \ube7c\uba39\uc740 UPDATE\/DELETE<\/strong>\uc785\ub2c8\ub2e4. \ud55c \ud589\uc744 \ubc14\uafb8\ub824\ub2e4 100\ub9cc \ud589\uc744 \ub0a0\ub9bd\ub2c8\ub2e4. \ub2e4\uc74c \ub450 \uc904 \ud328\ud134\uc744 \ubab8\uc5d0 \uc0c8\uae30\uc138\uc694.<\/p>\n<\/div>\n\n<pre><code>-- 1\ub2e8\uacc4: \uc601\ud5a5 \ubc1b\uc744 \ud589\uc744 \uba3c\uc800 \ud655\uc778\nSELECT id, name, email FROM users WHERE id = 5;\n-- \uacb0\uacfc 1\uac74 \u2192 \uc758\ub3c4\uc640 \ub9de\uc74c \ud655\uc778\n\n-- 2\ub2e8\uacc4: \uac19\uc740 WHERE \ub85c \uc2e4\uc81c \ubcc0\uacbd\nDELETE FROM users WHERE id = 5;<\/code><\/pre>\n\n<p>\ub610 \ud558\ub098\uc758 \uc548\uc804\ub9dd: \uc791\uc5c5 \uc804\uc5d0 \ud2b8\ub79c\uc7ad\uc158\uc744 \uc5f4\uc5b4\ub450\uae30.<\/p>\n\n<pre><code>BEGIN;\nDELETE FROM users WHERE active = false;\n-- \uc601\ud5a5 \ud589 \uc218 \ucd9c\ub825\ub428: \uc608) DELETE 7\n-- \uc798\ubabb \ub410\uc73c\uba74:\nROLLBACK;\n-- \ub9de\uc73c\uba74:\nCOMMIT;<\/code><\/pre>\n\n<p>\ud2b8\ub79c\uc7ad\uc158\uc740 14\ud3b8\uc5d0\uc11c \uae4a\uac8c \ub2e4\ub8f9\ub2c8\ub2e4. \uc785\ubb38 \ub2e8\uacc4\uc5d0\uc11c\ub3c4 &#8220;\uc6b4\uc601 DB \uc5d0\uc120 \ubb34\uc870\uac74 BEGIN\/COMMIT \uc0ac\uc774\uc5d0&#8221; \ub77c\ub294 \uc2b5\uad00\ub9cc \ub4e4\uc774\uc138\uc694.<\/p>\n\n<h2>\uc2e4\uc804 \ud328\ud134 \u2014 UPSERT \ud55c \uc904<\/h2>\n\n<pre><code>-- \"\uc788\uc73c\uba74 \uc5c5\ub370\uc774\ud2b8, \uc5c6\uc73c\uba74 \uc0bd\uc785\" \u2014 PostgreSQL \uc815\ud1b5 \ubc29\uc2dd\nINSERT INTO users (id, name, email, age)\nVALUES (1, '\uc900\uc131', 'jspark1st@gmail.com', 39)\nON CONFLICT (id) DO UPDATE\n  SET name  = EXCLUDED.name,\n      email = EXCLUDED.email,\n      age   = EXCLUDED.age;<\/code><\/pre>\n\n<p><code>ON CONFLICT<\/code> \ub294 \ucda9\ub3cc(PK\/UNIQUE) \uc2dc \ub3d9\uc791\uc744 \uc815\ud569\ub2c8\ub2e4. <code>DO NOTHING<\/code> \uc73c\ub85c \ubb34\uc2dc\ub3c4 \uac00\ub2a5. \uc2e4\ubb34\uc5d0\uc11c \ub3d9\uae30\ud654\u00b7\uc7ac\uc2dc\ub3c4\uc5d0 \ub9e4\uc6b0 \uc790\uc8fc \uc4f0\ub294 \ud328\ud134\uc774\uc5d0\uc694.<\/p>\n\n<div class=\"cta\">\n  <h3>6\ud3b8 \u2014 WHERE \uc808 \uc804\ubb38\uac00 (\uae30\ucd08 \uc2dc\uc791)<\/h3>\n  <p>\ube44\uad50\u00b7BETWEEN\u00b7IN\u00b7LIKE\u00b7NULL \u2014 \uc870\uac74 \ud45c\ud604\uc758 \uc815\uc11d\uacfc NULL 3\uac12 \ub17c\ub9ac\uc758 \ud568\uc815.<\/p>\n<\/div>\n\n<div class=\"series-nav\">\n  <strong>\ud83d\udcda PostgreSQL \ubc30\uc6b0\uae30 \uad50\uc7ac<\/strong><br>\n  \uc774\uc804: 4\ud3b8 \ub370\uc774\ud130 \ud0c0\uc785 \u00b7 \ud604\uc7ac: <strong>5\ud3b8 (\uc785\ubb38 \ub9c8\uc9c0\ub9c9)<\/strong> \u00b7 \ub2e4\uc74c \u2192 6\ud3b8 WHERE (SQL \uae30\ucd08 \uc2dc\uc791) \u00b7 \uc9c4\ud589: <strong>5\/24<\/strong>\n<\/div>\n\n<\/article>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>\uccab CRUD 4\uc885 + UPDATE\/DELETE \uc758 \ud55c \uac00\uc9c0 \uc548\uc804 \uaddc\uce59. 24\ud3b8 \uad50\uc7ac 5\ud3b8.<\/p>\n","protected":false},"author":1,"featured_media":268,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[19],"tags":[],"class_list":["post-487","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-postgresql"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/junai.ai\/blog\/wp-json\/wp\/v2\/posts\/487","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/junai.ai\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/junai.ai\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/junai.ai\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/junai.ai\/blog\/wp-json\/wp\/v2\/comments?post=487"}],"version-history":[{"count":0,"href":"https:\/\/junai.ai\/blog\/wp-json\/wp\/v2\/posts\/487\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/junai.ai\/blog\/wp-json\/wp\/v2\/media\/268"}],"wp:attachment":[{"href":"https:\/\/junai.ai\/blog\/wp-json\/wp\/v2\/media?parent=487"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/junai.ai\/blog\/wp-json\/wp\/v2\/categories?post=487"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/junai.ai\/blog\/wp-json\/wp\/v2\/tags?post=487"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}