A is a structured collection of information stored in a computer system. It organizes and manages data, allowing users to retrieve and manipulate information efficiently. A database is used to communicate with a database management system (DBMS) and perform various operations.
() is a subset of the database language that specifically deals with creating, altering, and dropping database objects. It enables users to define the structure and organization of data within a database. A is a logical container within a database that defines the layout of tables, relationships, and s.
A is a basic building block of a table, representing a specific attribute or field. Constraints are rules that enforce data integrity and consistency in the database. is a constraint that uniquely identifies each record in a table. establishes a relationship between two tables, referencing the primary key of another table.
(Structured Query Language) is a widely-used language for interacting with databases. It encompasses both the DDL and (DML). DDL statements such as , , , and are used to define, modify, and remove database objects.
To add a new column to an existing table, the command is utilized. Conversely, to remove a column from a table, the statement is employed. Lastly, is a DDL statement used to change the name of an existing table.
Keywords
foreign key | create table | rename table | ddl | constraint | language | database | column | primary key | data manipulation language | sql | drop table | schema | database definition language | drop column | alter table | truncate table | add column |
