SQL Fundamentals Vocabulary

Flashcards for SQL Fundamentals

Query

A specific request for data manipulation issued by the end-user or the application to the DBMS.

SQL

Stands for Structured Query Language; consists of commands that create database and table structures, perform data manipulation, and query the database.

CREATE DATABASE

SQL command used to create a new database. Syntax: CREATE DATABASE database_name;

DROP DATABASE

SQL command used to delete an existing database. Syntax: DROP DATABASE database_name;

CREATE TABLE

SQL command used to create a new table in a database. Syntax: CREATE TABLE table_name (column1 datatype, …);

DROP TABLE

SQL command used to delete an existing table. Syntax: DROP TABLE table_name;

TRUNCATE TABLE

SQL command used to delete only the data within a table. Syntax: TRUNCATE TABLE table_name;

ALTER TABLE

SQL command used to add, delete, or modify columns in an existing table.

NOT NULL constraint

Ensures that a column cannot have a NULL value.

UNIQUE constraint

Ensures that all values in a column are different.

PRIMARY KEY constraint

Uniquely identifies each row in a table.

FOREIGN KEY constraint

Uniquely identifies a row in another table, establishing a link between two tables.

CHECK constraint

Ensures that all values in a column satisfy a specific condition.

DEFAULT constraint

Sets a default value for a column when no value is specified during insertion.

SQL Data Types

Categories include: Exact numeric, Approximate numeric, Date and time, Character strings, Unicode character strings, Binary strings, and other data types.

SQL Operators

Categories include: Arithmetic, Comparison, Compound, and Logical operators.