About This Chapter
Managing Data in Databases - Chapter Summary
This chapter focuses on basic information you'll need to know to oversee data management responsibilities. You will have the opportunity to review SQL DROP commands for viewing, tables, columns and rows, as well as Data Definition Language (DDL) and Data Manipulation Language (DML) commands. Lessons also cover database triggers and SQL TRUNCATE commands.
These short text lessons are written by experienced instructors and can be printed for easy reference. Each lesson contains a self-assessment quiz that you can use to measure what you've learned and what you might need to further review. You can also contact instructors with any questions about lesson content.
How It Helps
Knowledge of data manipulation and commands is important in maintaining a company's crucial data, and your understanding of this material could help you advance in your career. Mastering these tools demonstrates your professionalism and dedication and could be a factor as you seek to begin or further your career in IT.
By the end of this chapter, you'll be able to:
- Describe the uses for Data Definition Language and Data Manipulation Language
Data Manipulation Language (DML)
- Correctly use SQL DROP commands for indexes, databases, temp tables and constraints
- Apply TRUNCATE string and table commands
- Explain the differences between DDL, DML and DCL in MySQL
- Understand basic DDL and DML commands
- Maintain information integrity with database triggers
1. Data Definition Language (DDL): Definition & Example
This lesson will cover data definition language (DDL), which is a concept that describes SQL tools used to manipulate database structures. You can create, change, and remove tables, table constraints, and other database objects.
2. Data Manipulation Language (DML): Definition & Example
Data Manipulation Language is actually a way to talk to databases that was first used by computers before being adapted by humans via SQL. Sound backwards? Read this lesson to find out more.
3. What are DDL, DML and DCL in MySQL?
Information comes us at from many directions. Databases help us make sense of the information in our world. In this lesson, we'll take a look at a specific example, MySQL, and the commands that can be employed to make sense of data.
4. Data Definition Language (DDL) Commands
Data definition language (DDL) is a unique set of SQL commands that lets you manipulate the structure of the database. In this lesson, we will explore these commands and see them in action.
5. Data Manipulation Language (DML) Commands
This lesson will cover data manipulation language (DML) commands in database management systems. These are commands that query, modify, and delete data in a database; they cannot modify the structure.
6. SQL DROP Columns & Rows: Tutorial
This lesson reviews the syntax for dropping columns and rows from a database using SQL. Deleting a column removes a data field; removing a row deletes a record of data.
7. SQL DROP Constraint: Tutorial & Overview
In this lesson, we will learn about the SQL drop constraint command, which is used to remove the constraint that limits the kind of data that can be saved in a database table.
8. SQL DROP Table: Tutorial & Explanation
How can you keep your database from being overrun with information? Make some space with DROP TABLE! This lesson will discuss the SQL process for dropping a table (DROP TABLE). The basic syntax will be discussed, as well as examples from two major database systems: Oracle and SQL Server.
9. SQL DROP Temp Table: Tutorial & Explanation
A temporary table should only be temporary: when it's no longer needed, drop it. This lesson covers how to drop a temporary table in SQL, including syntax and examples.
10. SQL DROP Index & DROP Database: Tutorial
We collect and organize information, lots of it. So it makes sense that we'll want to delete some of it at times. In this lesson, we'll take a look at SQL, indexes, databases, and how the DROP command affects them.
11. SQL DROP View: Tutorial & Overview
The SQL DROP command may be one that asks for caution, since it removes data. However, dropping a View does not delete the source data. This lesson will cover the DROP View command, providing an overview and examples.
12. SQL TRUNCATE String: Tutorial & Overview
SQL offers some nifty commands to manipulate and work with strings. In this lesson, we'll discuss three commands, each with their own uses, that can reduce strings to an appropriate size.
13. SQL TRUNCATE Table: Tutorial & Explanation
This lesson will cover the SQL TRUNCATE statement, providing a brief tutorial of the command and some code examples from various database management systems.
14. Database Triggers: Examples & Overview
Database triggers are small sets of code attached to database tables that can automate many database functions when activated by a single command. This lesson looks at common database trigger constructs and examples.
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