What is the full form of DML?
The Full Form of DML is Data Manipulation Language.
Data Manipulation Language (DML) is a programming language, also a category of SQL, applying useful table format and formulas for exchanging information, with the data limited to a point in the database, using SQL. However, a time might occur when data interactions that are fairly complicated are required. In this instance, Data Manipulation Language is applicable.
With the help of DML, we can easily tell the database how it should respond. For this, the way of communication adapted has been created to understand from the beginning. It also delivers a very convenient method to interact with the existing data by adding, deleting or transferring data.
Meanwhile, the Database Management System sets the framework of features or languages to alter or change the data, known as the Data Manipulation Language (DML). It becomes possible to manipulate data by entering SQL queries or via a typical Query-by-Example (QBE) graphical interface. One can also alter the tabulated data, with the help of these declarations, which also function on results. You cannot find any link to the table structure for statements such as these. Manipulation of data also enables the introduction of tables, resulting in modification of the information in the table and removing it.
For DML statements, control over the transaction is needed. The alteration that DML statement does to the database is called a transaction. Thus, if any adjustment is made via DML statement, then it will be managed by Transaction Control Language(TCL) statements. It is also SQL statements’ subset that can go on to modify the data in tables. It also chiefly focuses on performance of the database, while it makes use of the append-only feature of the Hadoop Distributed File System(HDFS) storage.
Data Manipulation Language (DML) Types
There are two types of DML, divided into the High-Level or Non-Procedural DML and the Low-level or Procedural DML.
- High-Level or Non-Procedural DML
- It is set for a particular time or is highly series oriented
- Only applied to determine very complex operations within the database
- Prescriptive by nature
- Specify the data that is required
- Does not state how or when to avail the data
- For example, Every SQL statement is a prescriptive command issued.
- Low-level or Procedural DML
- Called track-at-a-time DML
- Consolidated as a programming language for general purpose
- Necessary in nature
- Clearly state which data to access and how
- Example: DB2’s SQL PL, Oracle’s PL/SQL
Features of DML
- Runs only data interpretation queries
- Used in database schema to recall or manipulate data
Meanwhile, DML commands are given below:
Step 1: Select Command- start by giving a command, which is applied to get information out of the database. This also allows the database users to get the crucial data they require from an OS, while also transferring a track result established from one or more of the tables.
See below for example of a command:
Step 2: INSERT Command –This is used to submit the information or values into a row. With the help of this instruction, we would be able to connect a single or multiple records to one table within a repository. This is often used to fix an unused tag to the document.
INSERT INTO <table_name> (‘column_name1’ <datatype>, ‘column_name
VALUES (‘value1’, ‘value2’);
Step 3: Update Command- used to modify the existing table records. It changes the data from one or more records in a table, thus it is used to modify data within a table.
SET <column_name = value>
Step 4: Delete/Erase Command- used to delete a few or the entire data from the earlier table. If the “where” condition is not input, then all the rows would be eliminated.
DELETE FROM <table_name>
Advantages of DML
- Modify the data stored within the database
- Deliver effective human contact with the machine
- Could determine what data is needed
- DML offer several varieties and operations between the vendors that deliver the database
Disadvantages of DML
- Cannot be used to modify the database’s structure
- Restrict the table view, that is, DML could hide some table columns
- Access data without storing it in the device
- Should not be used to create or delete sections or lists
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