Primary Key
A column or set of columns that uniquely identifies each row in a database table.
In Depth
A primary key is a constraint that uniquely identifies each record in a database table. It must contain unique values and cannot contain NULL values. A table can have only one primary key, which may consist of a single column (simple key) or multiple columns (composite key). Primary keys serve as the main reference point for a record and are used by foreign keys in other tables to establish relationships. Common primary key strategies include auto-incrementing integers, UUIDs (Universally Unique Identifiers), and natural keys (meaningful values like email or ISBN). The choice of primary key impacts performance, scalability, and data distribution.
How AI for Database Helps
AI for Database recognizes primary keys in your schema to correctly identify records and construct accurate queries.
Related Terms
Foreign Key
A column in one table that references the primary key of another table, establishing a link between them.
Index
A database structure that speeds up data retrieval by creating an optimized lookup path for specific columns.
Relational Database
A database that organizes data into structured tables with rows and columns, linked by defined relationships.
Schema
The structural blueprint of a database that defines tables, columns, data types, relationships, and constraints.
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