A primary key is a column in a database table that uniquely identifies each row. Each table can have only ONE primary key, and it can’t be left empty.
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Learn SQL faster with a free SQL client that shows your database visually in an ER diagram. See tables, relationships, query results, and edit data easily.
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The easiest way to create a new user in your MySQL database and grant privileges
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Generate interactive database documentation in HTML5, PDF, or Markdown using DbSchema. Add diagrams, comments, and sync everything with Git.
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A foreign key links one table to another by matching values, usually to a primary key. It keeps data accurate and prevents invalid references.
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Discover an ER diagram tool for IBM Db2 that simplifies schema modeling, database management, querying, Git integration, and documentation. Try it free for 30 days.
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Visual guide for Apache Derby: create diagrams, edit schema, sync changes, generate docs, and explore data. No SQL required. Try DbSchema free.
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Create or explore ER diagrams for your SQLite database using a free modeling tool. Visual design, schema sync, Git support, and interactive documentation.
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Understand MongoDB aggregation pipelines with clear examples. Learn how to filter, group, sort, and transform data step by step in this beginner-friendly guide.
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In this article, you are going to find the default username and password for mysql and how to reset the password.
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