{"id":139,"date":"2022-02-11T13:37:16","date_gmt":"2022-02-11T13:37:16","guid":{"rendered":"https:\/\/openquery.com\/?p=139"},"modified":"2022-02-28T13:57:43","modified_gmt":"2022-02-28T13:57:43","slug":"what-is-ddl","status":"publish","type":"post","link":"https:\/\/openquery.com\/what-is-ddl\/","title":{"rendered":"What Is DDL?"},"content":{"rendered":"\n

If you\u2019re dealing with databases, it\u2019s only a matter of time before you come across the term DDL, which is an abbreviation of Data Definition Language, three words capable of striking fear in the heart of almost anyone without a computer science degree.<\/p>\n\n\n\n

Don\u2019t worry, though, it\u2019s nothing to be scared of. In fact, the sole purpose of DDL is to make your life easier. <\/p>\n\n\n\n

Using this nifty database tool, you can make crucial changes to your database objects in a matter of seconds \u2014 sounds pretty good, right?<\/p>\n\n\n\n

So, let\u2019s dig a little deeper into DDL and set out in plain English exactly what it is!<\/p>\n\n\n\n

\"What<\/figure><\/div>\n\n\n\n

Terminology Surrounding DDL<\/strong><\/h2>\n\n\n\n

The problem people face when trying to understand DDL is that it\u2019s surrounded by other forms of impenetrable techie jargon, so let\u2019s address those first.<\/p>\n\n\n\n

Database<\/strong><\/h3>\n\n\n\n

Let\u2019s start simple. DDL is used in database management. A database is simply any digital location that holds multiple pieces of data in a logical and easy-to-understand manner. <\/p>\n\n\n\n

Databases are made up of database objects.<\/p>\n\n\n\n

Database Objects<\/strong><\/h3>\n\n\n\n

Database objects are any structures used within the database as a whole to store and display data. <\/p>\n\n\n\n

For example, the most common and simple database object is a table. Another example of a database object would be an index or sequence. Make sense?<\/p>\n\n\n\n

It may help to think of databases, database objects, and data as a grocery store\u2026<\/p>\n\n\n\n

The database is the building. <\/p>\n\n\n\n

Once you arrive at and enter the building, the database objects are like the shelves, fridges, and freezers, and the data is like the produce held in or on all these modes of presentation \u2014 simple, huh?<\/p>\n\n\n\n

SQL<\/strong><\/h3>\n\n\n\n

Another scary abbreviation, SQL stands<\/a> for Structured Query Language, and it\u2019s essentially an umbrella term for database languages DDL and DML. <\/p>\n\n\n\n

You can kind of think of DDL and DML as different regional dialects of the same language, that language being SQL.<\/p>\n\n\n\n

\u2026 and with those definitions taken care of, we can finally dig into DDL \u2014 hooray!<\/p>\n\n\n\n

Just What The Heck Is DDL?<\/strong><\/h2>\n\n\n\n

DDL is a database programming language, and it\u2019s used specifically for modifying and creating database objects. <\/p>\n\n\n\n

Now, just to refresh your memory, database objects were the shelves, fridges, and freezers in our metaphorical grocery store.<\/p>\n\n\n\n

Remember the days of My Space and furiously typing HTML to make your profile super cool? <\/p>\n\n\n\n

Well, in a way, DDL is kind of like a very specific and simple form of HTML designed to be as efficient as possible in order to streamline database management.<\/p>\n\n\n\n

As a subset of SQL which uses standard English as opposed to the more code-like structure of HTML, DDL is mostly composed of imperative verbs\u2026 it\u2019s got sort of a bossy caveman vibe to it. <\/p>\n\n\n\n

But that\u2019s exactly what you need for whipping a database into shape in record time.<\/p>\n\n\n\n

In some contexts, you may hear that DDL stands for Data Description Language, as it also describes the metrics of a database, i.e. what sort of data is being displayed.<\/p>\n\n\n\n

Okay, But How Is DDL Different From DML?<\/strong><\/h2>\n\n\n\n
\"Okay,<\/figure><\/div>\n\n\n\n

In both subsets of SQL, people often get confused about how DDL and DML differ, and, granted, they do seem quite similar to the laymen, but in actual fact, they are very, very different. Let\u2019s explore how\u2026<\/p>\n\n\n\n

Heading back to our metaphorical grocery store, we have the shelves (database objects), and we have the produce on the shelves (data). <\/p>\n\n\n\n

DDL is the tool we\u2019d use to add more shelves, take shelves away, or modify existing shelves. DML (Data Modification Language), on the other hand, would be used to modify the produce sitting on the shelves.<\/p>\n\n\n\n

DML can be used to alter large amounts of data in one fell swoop, saving some poor souls from having to edit each individual piece of data manually. <\/p>\n\n\n\n

DDL is used to structure said data efficiently, so the same poor soul doesn\u2019t have to create all the database objects themselves on a spreadsheet.<\/p>\n\n\n\n

Examples Of DDL<\/p>\n\n\n\n

Possibly the best way to come to terms with DDL is to take a look at a few commonly used examples. The ones we\u2019ll discuss briefly today include:<\/p>\n\n\n\n