[{"data":1,"prerenderedAt":133},["ShallowReactive",2],{"term-o\u002Fone-to-many":3,"related-o\u002Fone-to-many":115},{"id":4,"title":5,"acronym":6,"body":7,"category":95,"description":96,"difficulty":97,"extension":98,"letter":99,"meta":100,"navigation":101,"path":102,"related":103,"seo":109,"sitemap":110,"stem":113,"subcategory":6,"__hash__":114},"terms\u002Fterms\u002Fo\u002Fone-to-many.md","One-to-Many",null,{"type":8,"value":9,"toc":89},"minimark",[10,15,19,23,26,30,78,82,85],[11,12,14],"h2",{"id":13},"eli5-the-vibe-check","ELI5 — The Vibe Check",[16,17,18],"p",{},"One-to-Many means one row in Table A can relate to many rows in Table B. One user can have many orders. One post can have many comments. It is the most common relationship in databases and is implemented with a foreign key on the 'many' side.",[11,20,22],{"id":21},"real-talk","Real Talk",[16,24,25],{},"A one-to-many relationship means that one record in the parent table can be referenced by multiple records in the child table. The child table holds the foreign key pointing to the parent's primary key. It is the most fundamental relationship in relational database design.",[11,27,29],{"id":28},"show-me-the-code","Show Me The Code",[31,32,37],"pre",{"className":33,"code":34,"language":35,"meta":36,"style":36},"language-sql shiki shiki-themes material-theme-lighter material-theme material-theme-palenight","-- One user, many orders\nCREATE TABLE orders (\n  id SERIAL PRIMARY KEY,\n  user_id INT REFERENCES users(id),  -- many side\n  total DECIMAL\n);\n","sql","",[38,39,40,48,54,60,66,72],"code",{"__ignoreMap":36},[41,42,45],"span",{"class":43,"line":44},"line",1,[41,46,47],{},"-- One user, many orders\n",[41,49,51],{"class":43,"line":50},2,[41,52,53],{},"CREATE TABLE orders (\n",[41,55,57],{"class":43,"line":56},3,[41,58,59],{},"  id SERIAL PRIMARY KEY,\n",[41,61,63],{"class":43,"line":62},4,[41,64,65],{},"  user_id INT REFERENCES users(id),  -- many side\n",[41,67,69],{"class":43,"line":68},5,[41,70,71],{},"  total DECIMAL\n",[41,73,75],{"class":43,"line":74},6,[41,76,77],{},");\n",[11,79,81],{"id":80},"when-youll-hear-this","When You'll Hear This",[16,83,84],{},"\"A user has a one-to-many relationship with orders.\" \u002F \"Put the foreign key on the 'many' side.\"",[86,87,88],"style",{},"html .light .shiki span {color: var(--shiki-light);background: var(--shiki-light-bg);font-style: var(--shiki-light-font-style);font-weight: var(--shiki-light-font-weight);text-decoration: var(--shiki-light-text-decoration);}html.light .shiki span {color: var(--shiki-light);background: var(--shiki-light-bg);font-style: var(--shiki-light-font-style);font-weight: var(--shiki-light-font-weight);text-decoration: var(--shiki-light-text-decoration);}html .default .shiki span {color: var(--shiki-default);background: var(--shiki-default-bg);font-style: var(--shiki-default-font-style);font-weight: var(--shiki-default-font-weight);text-decoration: var(--shiki-default-text-decoration);}html .shiki span {color: var(--shiki-default);background: var(--shiki-default-bg);font-style: var(--shiki-default-font-style);font-weight: var(--shiki-default-font-weight);text-decoration: var(--shiki-default-text-decoration);}html .dark .shiki span {color: var(--shiki-dark);background: var(--shiki-dark-bg);font-style: var(--shiki-dark-font-style);font-weight: var(--shiki-dark-font-weight);text-decoration: var(--shiki-dark-text-decoration);}html.dark .shiki span {color: var(--shiki-dark);background: var(--shiki-dark-bg);font-style: var(--shiki-dark-font-style);font-weight: var(--shiki-dark-font-weight);text-decoration: var(--shiki-dark-text-decoration);}",{"title":36,"searchDepth":50,"depth":50,"links":90},[91,92,93,94],{"id":13,"depth":50,"text":14},{"id":21,"depth":50,"text":22},{"id":28,"depth":50,"text":29},{"id":80,"depth":50,"text":81},"database","One-to-Many means one row in Table A can relate to many rows in Table B. One user can have many orders. One post can have many comments.","beginner","md","o",{},true,"\u002Fterms\u002Fo\u002Fone-to-many",[104,105,106,107,108],"One-to-One","Many-to-Many","Foreign Key","ERD","Junction Table",{"title":5,"description":96},{"changefreq":111,"priority":112},"weekly",0.7,"terms\u002Fo\u002Fone-to-many","kT4owkgi4XrJpSynKudDwDEmod4sTlHwiQroeRSVOfQ",[116,121,124,127,130],{"title":107,"path":117,"acronym":118,"category":95,"difficulty":119,"description":120},"\u002Fterms\u002Fe\u002Ferd","Entity Relationship Diagram","intermediate","An ERD is a visual map of your database — boxes for tables, lines showing how they connect.",{"title":106,"path":122,"acronym":6,"category":95,"difficulty":97,"description":123},"\u002Fterms\u002Ff\u002Fforeign-key","A foreign key is how you link two tables together. If an 'orders' table has a 'user_id' column pointing to the 'users' table, that is a foreign key.",{"title":108,"path":125,"acronym":6,"category":95,"difficulty":119,"description":126},"\u002Fterms\u002Fj\u002Fjunction-table","A junction table (also called a join table) is the middle table you create to represent a many-to-many relationship.",{"title":105,"path":128,"acronym":6,"category":95,"difficulty":119,"description":129},"\u002Fterms\u002Fm\u002Fmany-to-many","Many-to-Many means rows on both sides can relate to many rows on the other side. Students can enroll in many courses, and courses can have many students.",{"title":104,"path":131,"acronym":6,"category":95,"difficulty":97,"description":132},"\u002Fterms\u002Fo\u002Fone-to-one","One-to-One is a relationship where one row in Table A corresponds to exactly one row in Table B. Like a user and their profile — one user, one profile.",1776518299190]