Editing SQL (section)

== <span style="color: #FFFFFF;">Remembering</span> ==
Key terms:

* '''Database''' � an organized collection of structured data stored electronically.
* '''Relational database''' � a database that organizes data into tables with defined relationships between them.
* '''Table''' � a grid of rows and columns, similar to a spreadsheet, representing one type of entity (e.g., users, orders).
* '''Row (record)''' � a single entry in a table.
* '''Column (field)''' � a named attribute shared by all rows in a table (e.g., "email", "created_at").
* '''Primary key''' � a column (or combination) that uniquely identifies each row.
* '''Foreign key''' � a column that references the primary key of another table, linking them.
* '''Query''' � a request for data, written in SQL.
* '''Schema''' � the blueprint describing a database's tables, columns, and relationships.
* '''Index''' � a data structure that speeds up lookups on a column at the cost of extra storage.
* '''NULL''' � the absence of a value; distinct from zero or empty string.

Core SQL statement categories:
* '''SELECT''' � retrieve data
* '''INSERT''' � add new rows
* '''UPDATE''' � modify existing rows
* '''DELETE''' � remove rows
* '''CREATE / DROP / ALTER''' � define or change the schema (DDL � Data Definition Language)
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