Database Systems Final Exam 2023 with 100% correct answers

SQL is a domain-specific programming language designed for managing and communicating with data held in a relational database management system SQL is used for: -creating databases -adding, modifying and deleting database structures -inserting, deleting and modifying records in databases -querying databases Data Definition Language (DDL) used to create and modify the structure of the database example: CREATE ALTER or DROP Data Manipulation Language (DML) used to insert, modify, delete and retrieve data example: INSERT INTO UPDATE or DELETE Data Retrieval Language (DRL) used to query or retrieve data from a database example: SELECT Data Control Language (DCL) used for data access control Transaction Control Language used for managing database transactions Keywords These have a very specific meaning in the language. The statement must have at least one. These often define the operation that is performed Identifiers These refer to the names of the tables and columns that are called or manipulated Null Value is a marker for data that has not been entered or is missing, unknown, or inapplicable Not Null Constraint is only a column constraint and not a table constraint; if you don't specify a _____, the column will accept null values by default Unique Constraint forces each value of a column or table to be unique Check Constraint allows for limiting a particular column based on a particular value rules These include: minimum or maximum value specified value range of values ALTER table provides the ability to: -add/drop a column -alter a column's data type -rename a column -rename a table -add, alter or drop a column's default value or null ability constraint -add, alter or drop column or table constraints such as primary key, foreign key, unique and check constraint Select Statement is the basic building block of any data query request. It is command that pulls specific data from a particular table within the database highlighted