SQL, which stands forStructured Query Language, is a powerful language used for managing and manipulating relational databases. In this comprehensive guide, we will delve into SQL commands, their types, syntax, and practical examples to empower you with the knowledge to interact with databases effect...
Syntax Select * from Table_Name; Example Select * from Student; SQL Copy DML(Data Manipulation Language) Command in SQL DML or Data Manipulation Language is to manipulate the data inside the database. With the help of DML commands, we can insert, delete, and change the data inside the ...
In this section, we will be discussing types of SQL commands. SQL Commands are divided into five broad categories – DDL, DML, DCL, TCL, and DQL. Each category is further explained below: 1. Data Definition Language(DDL): The Data Definition Language is made up of SQL commands that can ...
Data Definition Language (DDL) commands are used for defining the database structure or schema. Let's look at some DDL commands with a simple example for each command. i. CREATE In SQL, theCREATE TABLEcommand is used to create a new table in the database. For example, CREATETABLEProducts...
Following is commit command's syntax,COMMIT;ROLLBACK commandThis command restores the database to last commited state. It is also used with SAVEPOINT command to jump to a savepoint in an ongoing transaction.If we have used the UPDATE command to make some changes into the database, and ...
Syntax: TRUNCATE TABLE table_name; Example:Deletes all the rows from the tableEmployees. TRUNCATE TABLE EMPLOYEES; 2. DML (Data Manipulation Language) SQL commands that deals with the manipulation of data comes under DML category. The popular commands that come under DML are: ...
Learn the basic syntax of TCL programming language. Understand commands, variables, and control structures effectively.
You can see in the previous namespace examples, we use a lot of scope resolution operator and it's more complex to use. We can avoid this by importing and exporting namespaces. An example is given below −Open Compiler #!/usr/bin/tclsh namespace eval MyMath { # Create a variable ...
applications, such as variables and loops and procedures. Furthermore, Tcl is embeddable: its interpreter is implemented as a library of C procedures that can easily be incorporated into applications, and each application can extend the core Tcl features with additional commands specific to that ...
The two grep commands might have been combined into one, but in this case I decided it would be easier to reuse and adapt the previous pipeline. There’s no shame in being pragmatic in order to get the job done! 5.3.3 Replacing and Deleting Values You can use the command-line tool ...