Creating‚ dropping‚ and altering tables in SQLite In this part of the SQLite tutorial‚ we will cover the data definition language (DDL) of the SQLite database. The DDL consists of SQL statements that define the database schema. The schema is the database structure described in a formal language. In relational databases‚ the schema defines the tables‚ views‚ indexes‚ relationships‚ or triggers. The SQLite supports the following three DDL statements: CREATE ALTER TABLE DROP In SQLite‚ the CREATE statement
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reference: http://www.tutorialspoint.com/sql important: constrains: SQL constraints are used to specify rules for the data in a table. If there is any violation between the constraint and the data action‚ the action is aborted by the constraint. In SQL‚ we have the following constraints: NOT NULL - Indicates that a column cannot store NULL value UNIQUE - Ensures that each rows for a column must have a unique value PRIMARY KEY - A combination of a NOT NULL and UNIQUE. Ensures that
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Delta Initiative Guide to SQL Injection Introduction SQL injection is a hacking technique used to exploit weaknesses in applications. When programs are written‚ some parameters used in the creation of the application code can leave weaknesses in the program. The purpose of SQL injection is to convince the application to run SQL code that was not intended. SQL injection is a hacking method used to attack SQL databases; it’s usually delivered via a user input field. The input field is where
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Exam Name: Exam Type: Exam Code: Oracle Database: SQL Fundamentals Oracle 1Z0-051 Total Questions 114 Question: 1 Which statement is true regarding the INTERSECT operator? A. It ignores NULL values. B. Reversing the order of the intersected tables alters the result. C. The names of columns in all SELECT statements must be identical. D. The number of columns and data types must be identical for all SELECT statements in the query. Answer: D Question: 2 Which three statements
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The SQL CREATE TABLE Statement The CREATE TABLE statement is used to create a table in a database. Tables are organized into rows and columns; and each table must have a name. SQL CREATE TABLE Syntax CREATE TABLE table_name ( column_name1 data_type(size)‚ column_name2 data_type(size)‚ column_name3 data_type(size)‚ .... ); The column_name parameters specify the names of the columns of the table. The data_type parameter specifies what type of data the column can hold (e.g. varchar‚ integer‚ decimal
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threats and what can be done to prevent them. SQL Injection Attacks SQL injection is an attack on databases through the use of websites. This is done through the insertion of malicious code that is then passed into an instance of SQL Server for execution. The SQL injection follows the path of user-input in order to access the system through the loopholes that have been inadvertently left by developers in the input validation areas of the database. SQL injection takes advantage of the lack of checks
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PT2520 Instructor: Mounir Berrada Assignment 2 Unit 2 True/False Questions Indicate whether the following statements are true or false on the student answer sheet. 1) A requirement is something a database needs to do in order to fulfill its purpose. True 2) You only need to include the most important stakeholders in the database discussions. False 3) Forms are used for gathering input. True 4) A transaction database is optimized to track transactions in real time
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Assignment 3: SQL commands Thomas Edison State College Author Note This paper was prepared for CIS 311 Database Management taught by Mr. Bob O ’Brien Abstract SQL commands are lines of SQL code that ask the SQL application to perform simple tasks with data inside of a database. Often we refer to commands as query statements or scripts; all of these terms are synonymous. Most of the commands and statements are fairly standard and will work across multiple database applications. SQL commands are
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2 9. Which of the following is not a valid SELECT statement? a. SELECT cost-retail FROM books; b. SELECT retail+cost FROM books; c. SELECT retail * retail * retail FROM books; d. SELECT retail^3 from books; Week 3 3. Which of the following SQL statements is valid? a. SELECT order# FROM orders WHERE shipdate = NULL; b. SELECT order# FROM orders WHERE shipdate = ’NULL’; c. SELECT order# FROM orders WHERE shipdate = "NULL"; d. None of the statements are valid. 9. Which of the following
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U05A1 RELATIONAL DATABASE SYSTEM – SQL TUTORIAL IT2230 Introductions to Databases u05a1 Relational Database System – SQL Tutorial Assignment Overview of Lesson Assignments Table of Contents Overview of Lesson Assignments 2 LESSON 3 3 Exercise 1 3 Exercise 3 3 Exercise 5 4 Summary of Lesson 3 4 LESSON 4 5 Create Table Exercise 5 Summary of Lesson 4 5 LESSON 5 6
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