What is a DDL script and why is it so crucial for systems that use relational databases?
DDL scripts are widely used in creating, documenting, and migrating systems that use relational databases. They can be designed for simple tasks, such as migrating a database from one server to another, or for more complex tasks.
DDL scripts are read sequentially and are written in SQL with commands specific for defining data structures (
DROP). This article presents the concept behind these scripts and how to use them successfully.
Before we explain why you’d need a DDL SCRIPT, it is essential for you to understand what it is. DDL stands for Data Definition Language. This is a set of SQL commands used for creating, modifying, and removing database objects; its primary commands are
TRUNCATE. These instructions allow us to create, modify, and delete any object in an SQL database.
CREATE command creates database object structures, such as a new database, table, or index. This command also serves a variety of other purposes. Creating tables is one of the most frequent uses of the
CREATE command; the structure is as follows:
This example uses the
CREATE command to create a table called
Product. As you might guess, it stores product information. You start by calling
CREATE TABLE (indicating that you want to create a table). Then you open the parentheses and place the desired fields and their definitions inside, separating each new field with a comma. You end the command by closing the parentheses and adding a semicolon.
ALTER is used to change database object structures; you can use it to edit an existing object in your database. This would include adding or deleting a column from a table or updating a table to include a primary key. Here’s an example of an
ALTER statement used on our
In these three commands, you can see the versatility of the
ALTER command. In the first line, it is used to change the table and make the
id_product field a primary key. Next, this same command is used to insert a field called
vl_tax, which will be used to store the value of the tax on that product.
ALTER command is used to remove the
vl_price_sell column, which represents a product's sales value.
However, you need another command to delete objects. The
DROP command removes objects and even entire databases; it is how the deletion of tables, users, databases, and other structures is done. Here are two examples:
The syntax is simple but very efficient: You use the
DROP command followed by the type of element you want to destroy and the element’s name. In the snippet above,
DROP removes the table
Product (first line) and then the database
Store (second line).
TRUNCATE command immediately deletes all records from a table (but not the table itself or its structure). It is much faster than
DELETE because it does not write the data being removed to the transaction log. To remove all records from a table, you’d write:
It is important to note that since all data is not being written to transaction logs, it is impossible to use transactional control (
ROLLBACK, for example) to recover the deletion performed by the
TRUNCATE command. In other words, truncated data is permanently removed.
A DDL script can contain a lot of information that a database administrator, data analyst, or data engineer needs. Just a slight knowledge of SQL can help you decipher it. The comments are written in green and preceded by double hyphens (-). They are essential for mapping the script and recording what is being done during execution.
The menu on the right presents several functions that you can use to make your script even more specific to your needs. For example, you can define the database type. (Despite being a standard, DDL/SQL scripts have slight differences from one database to another, such as the way the data type is represented.)
Along with your script, you can run additional SQL scripts that allow you to perform actions before or after the
DROP commands. You can choose from dozens of script validation checks in Model Validation Settings (all selected by pattern) or choose the format in which your script will print. You can also change minor details like reference notations, table schemas, column details, primary keys, foreign keys, alternatives, and checks. Thus, the Vertabelo parameter configuration feature allows your script generation to be even more suited to your needs.
To generate your DDL script, click on the SQL item in the top bar; it will take you to the next screen, GENERATE SQL SCRIPT. Once there, indicate whether it is a
DROP DDL script (one serves to create the tables, the other to destroy them).
Next, select which elements you want to export (tables, references, sequences, etc.). Finally, choose if you will export only the selected elements or the entire database. Once this process is complete, click Generate.
Once your DDL script is finished, just download it or keep it saved in the Vertabelo drive, where it can be edited if necessary.
REVERSE ENGINEERING analyzes a system, object, or device (e.g. a database, a machine or a machine part, etc.) with the goal of understanding how it works. During this process, it examines structures, functions, and operations. In other words, it reworks the entire development to its initial design.
A great example of reverse engineering is disassembling a machine to analyze its parts and find out how it works. When applied to the database, reverse engineering is defined as redoing the whole development process using methodologies to return to the initial design from the actual physical structure. Database reverse engineering creates a document that maps the properties of the database and makes it easier to understand.
In incorrectly modeled and LEGACY SYSTEMS (years-old systems that no longer offer access to the original team/documentation), understanding the database can be a challenge: mapping the numerous tables, the correlations between them, their cardinalities, and even the type of data that exists in each field can be an arduous and extensive task.
Vertabelo facilitates this process, as it can GENERATE DDL SCRIPTS from a physical model. You can also build a new model by importing a DDL script, allowing entire databases to be quickly ported to an easy-to-understand environment and shared with other contributors who will help decipher the original purpose of that structure.
And if reverse engineering is not enough, you can also use DDL to generate migration scripts.
A system can have several versions, and its development can continue once a version is delivered. Therefore, it is common that a database is changed and its tables are modified after it is in use. Vertabelo allows a script to be generated from the new database version (as compared with the old one) and its updates to be applied. This kind of feature is precious for a company that needs to ensure the integrity of its production operation and wants to mitigate the damage that data loss might cause.
It is easy to understand the advantage of using Vertabelo for developing models and documenting legacy systems through the extraction and import of DDL scripts. These resources are very versatile. Even better, they allow more people to share the imported model, speeding up group work and system documentation.
Original article source at: https://www.vertabelo.com/
Hey peeps, Hope you all are safe & going well
Many entrepreneurs & startups are interested to start a crypto exchange platform by using a cryptocurrency exchange script, you know why??? Let me explain. Before that, you need to know what is a cryptocurrency exchange script???
Cryptocurrency Exchange Script is an upgrade version of all exchange platforms, it is also called ready-made script or software. By using the crypto exchange script you can launch your crypto trading platform instantly. It is one of the easiest and fastest ways to start your crypto exchange business. Also, it helps to launch your exchange platform within 7 days.
The More Important one is “Where to get the best bitcoin exchange script?”
No one couldn’t answer the question directly because a lot of software/script providers are available in the crypto market. Among them, finding the best script provider is not an easy task. You don’t worry about that. I will help you. I did some technical inspection to find the best bitcoin exchange script provider in the techie world. Speaking of which, one software provider, Coinsclone got my attention. They have successfully delivered 100+ secured bitcoin exchanges, wallets & payment gateways to their global clients. No doubt that their exchange software is 100% bug-free and it is tightly secured. They consider customer satisfaction as their priority and they are always ready to customize your exchange based on your desired business needs.
Of course, it kindles your business interest; but before leaping, you can check their free live demo at Bitcoin Exchange Script.
Are you interested in business with them, then connect their business experts directly via
#bitcoin exchange script #cryptocurrency exchange script #crypto exchange script #bitcoin exchange script #bitcoin exchange clone script #crypto exchange clone script
Are you wanting to be an Entrepreneur? A Business using cryptocurrency? Then this article is for you.
As a beginner, always one prefers fair play. But to the least, initiating business in the streams of cryptocurrency carries a varying degree of risks. We all know that, Every business packs the profit only if we are ready to take risks. But flabbergast is, you can avoid unnecessary risk, If you choose our Twisted HYIP Investment script. You don’t need to play poker with your hard-earned Money.
Using minimal investment, You can start a beneficial business.
Craze for cryptocurrency is now seeming to be unlimited, Using the Twisted HYIP platform you will get funds for running the lending business- this is the one line of the process.
First, let me make plain, How our traditional HYIP works?
You can create a number of investment plans with attractive and promising Rate of interest. Investors will invest in those plans and get their interest periodically.
How you will provide them interest? You have to collect the investments and use them for your own project, Trading, Stock marketing and so on.
What if you don’t find a right platform to grow your investor’s funds. You will lack in processing their interest, and it will be filthy, right?
How it works?
So this Twisted HYIP platform clear this shady cloud and brings you the best place to grow your investors’ funds. With our platform you can run Investment as well as lending platform together. You will run a traditional HYIP script for your investors stating the fixed Rate of interest with validity for processing their principle back.
Instead of using the crowded funds in different platform, You can use it for lending to borrowers in your platform at an interest rate higher than promised to your investors. Now you can pay back the investors as well as you will get a constant flow of income for you.
Instead of generating promised interest rate daily or monthly, You can also make it as a doubler with long term duration. So you can use the investors fund as well as lenders repay again and again.
Every investor can monitor their investment growth in their dashboard. They will get back their invested amount plus additional ROI only when their investment gets matures. But they can see, how their wallet is loaded with profits without any risk.
Possibility of being a Profitable business
Crucial bits of Twisted HYIP
Cryptocurrency market is blooming one, as per the voices of many financial expertise, prediction for end of digital currency is a blue moon. This twisted HYIP will create its own market as a perception for profit is getting increased every day among the people.
Now are you ready to launch your own lending platform? then Connect with KIR HYIP to know more interesting features about the platform. There is always space to add your ideas.
Under a short span of time, launch your own turnkey based lending platform. The World is running behind Profit, what are you waiting for? Join the club now and get the free HYIP software demo!
#hyip script #hyip investment script #bitcoin hyip script #buy hyip script #best hyip script #hyip investment script
HYIP projects are one of the growth trends of the internet and many investors are involved in it.
One of the quickest ways to get rich today is because so many people want to join this network.
Hyip concept is often referred to as a high-yield investment plan or scheme, while the main difference between this and other types of investments is high-yield and low-yield.
There are many HYIPs with different investment plans. Those are, Short and long term.
Start your own investment site by hand with the best HYIP script.
Explore every part of our software packaged with responsive design, multiple projects, and multiple currency support features. They provide quality products associated with efficient product endeavors that make our product shine in every aspect.
Sign in to the HYIP script demo now for free and explore its features and installation process.
Initial Coin Offering Projects:
In Today’s trend, ICO script also created a vast impact on collecting funds and gaining benefits valuable operations. The cost for building an ICO website is made easy as it is based on customers’ specifications of features.
Look into the constructive features as it holds the top graded properties and it supplies essential tokens needed for crowdfunding campaigns. The best software provider KIR HYIP presents a prodigious product.
The ICO Script is coordinated with corresponding lending and affiliate programs that actually work in a format of allowing investors to purchase tokens during a crowd sale and then provides right to get a guaranteed interest return in accordance with the amount of tokens purchased over a period of time.
The product is furnished with more attractive and essential features that support
Also, the script supports various cryptocurrencies in order to collect funds in an effective method. It is a combination for making investment and donation. The uncertainty over secure transactions is cleared out with strong security mechanism.
In comparison with the features the software comes up with the quality assured price. Check the demo here: ICO Script Demo
#hyip script #hyip software #bitcoin hyip script #buy hyip script #best hyip script #ico script
Are you interested in starting a cryptocurrency exchange??? Congrats, you’ve chosen the right business idea at the right time!!! Because cryptocurrency is gonna boom in the upcoming days. Recently, many governments are legalizing cryptocurrency in their countries. And more importantly, the pride of cryptocurrencies “Bitcoin crossed more than $50K”. So this is the right time to originate your crypto exchange business. Now you will have a question like this “How to start a bitcoin exchange in a safe & secure way?” For your unanswered question. I suggest a simple solution, that is “Bitcoin Exchange Clone Script”. But there are lots of crypto exchange clone scripts in the crypto market. Here I listed the Top 10 Cryptocurrency Exchange Scripts check it out below.
Top 10 Cryptocurrency Exchange Scripts:
Among these clone scripts many cryptopreneurs & enthusiasts most commonly use only 3 cryptocurrency exchange scripts.
These are 3 cryptocurrency exchange clone scripts that are widely used in the crypto space. “Who Provides these cryptocurrency exchange scripts???” That’s really hard to find because many crypto exchange clone script firms are available in the crypto market. So, finding the best one will be a kind of complicated task. Don’t worry; I will help you. I’ve done some technical aspects to identify & find the best crypto exchange clone script provider, as the end of the result one script/software provider (Coinsclone) cleared all my technical & non-technical hurdles. Coinsclone is one of the professional crypto exchange clone script providers. Their software/script is 100% secured & bug-free because their primary motto is client stratification. So that they have clients from all over the world. Till now they have successfully delivered 100+ crypto projects (Crypto exchange, Wallets & Payment gateway) for their clients.
If you are interested, you can check their free live demo @ Bitcoin Exchange Script demo.
Or else, you want to speak with their business experts directly. You can touch their experts via,
Whatsapp / Telegram @ +919500575285
#bitcoin exchange script #coinbase clone script #localbitcoins clone script #binance clone script #bitcoin exchange clone script #crypto exchange clone script
We studied that Crypto exchanges are highly proving to be major hit that users are actually returning to integrate in quality ways. Also it’s one I suggest checking out if you wish to unwind major benefits but have best strategies at the same time. Moreover the global users are actually surprised hearing Best Cryptocurrency Website Scripts raking in millions of dollars daily.
AppStoc - Start Your Own Bitcoin Exchange is as simple where AppStoc helps in all perspective. Why searches like how to start your own bitcoin exchange, bitcoin trading script, Bitcoin Exchange Script, cryptocurrency website scripts, bitcoin clone script, cryptocurrency exchange script, hyip script, hyip manager script, phphyipmanagerscript, hyiplisterscript, icosoftware are so valuable. AppStoc gives perfect answers for all these business modules.
It is also mentioned that the top 10 Crypto exchanges are highly generating as much $3 million in fees a day or heading for more than $1 billion per year. Are you wondering how? Yes. They are professionally making this through the highly complex development involved beyond their prosperous income.
This reputed firm AppStoc duly helps to find out people needs in finding steps to start your own bitcoin exchange, bitcoin trading script, Bitcoin Exchange Script, cryptocurrency website scripts, bitcoin clone script, cryptocurrency exchange script, hyip script, hyip manager script, phphyipmanagerscript, hyiplisterscript, icosoftware.
Amazingly it is enumerated that the exchanges and transaction processors are the huge winners in the space since they’re permitting global users to transact and participate in this burgeoning sector. Even the massive revenue estimates are conveying that the boom might exactly influence institutional sectors to invest in exchanges.
People search in for and wonder how to start your own bitcoin exchange, bitcoin trading script, Bitcoin Exchange Script, cryptocurrency website scripts, bitcoin clone script, cryptocurrency exchange script, hyip script, hyip manager script, phphyipmanagerscript, hyiplisterscript, icosoftware. For all these searches AppStoc has absolute answer in finding them right solution for global users.
AppStoc helps how to start your own bitcoin exchange. It also supplies bitcoin trading script, Bitcoin Exchange Script, cryptocurrency website scripts, bitcoin clone script, cryptocurrency exchange script for users.
Buy Bitcoin Exchange Script / Bitcoin Trading Script / Bitcoin Clone Script / Cryptocurrency website scripts / Cryptocurrency exchange script and Start Your Own Bitcoin Exchange from AppStoc
#cryptocurrency website scripts #bitcoin exchange script #cryptocurrency exchange script #bitcoin trading script #start your own bitcoin exchange #bitcoin clone script