SQL keys are essential for keeping databases organized and accurate! They ensure unique records, link tables, and maintain data integrity. Here’s a quick breakdown of the main types of SQL keys and why they matter. 🧵👇 #SQL #DataIntegrity #INDvSA #DataAnalytics

1.🔑 What are Keys in SQL? Keys in SQL are essential constraints used to uniquely identify rows in a table and establish relationships between tables. Think of them as anchors that maintain data accuracy and integrity across databases. #SQL #DataIntegrity

2. 🔑 Primary Key The Primary Key is a unique identifier for each record in a table. It ensures no duplicate entries. A table can only have one Primary Key, but it can be composed of multiple columns (composite key). #Database #PrimaryKey

3. 🔑 Composite Key A Composite Key is a Primary Key made up of two or more columns. This is useful when a single column can't uniquely identify rows. #SQLCompositeKey

4.🔑 Unique Key A Unique Key constraint ensures all values in a column or group of columns are unique (similar to Primary Key). But a table can have multiple Unique Keys, unlike the Primary Key. #SQLUniqueKey

5. 🔑 Foreign Key A Foreign Key links two tables together. It refers to the Primary Key of another table, creating a relationship that enforces referential integrity. Foreign Keys help prevent orphaned records. #ForeignKey #SQLRelationships

6. 🔑 Composite Foreign Key Like a Composite Key, a Composite Foreign Key uses multiple columns to create a relationship between tables. This is valuable when unique identification requires multiple columns. #SQLCompositeForeignKey

7. 🔑 Candidate Key A Candidate Key is a column (or set of columns) that can uniquely identify rows. Every table can have multiple Candidate Keys, but only one can be the Primary Key. #CandidateKey #DatabaseDesign