Essential SQL Commands: Query, Modify, and Manage Data

Posted by on Feb 27, 2025 in Computers | 0 comments

Frequently Used SQL Commands

DROP (Delete a Table)

DROP TABLE table_name;

DROP TABLE IF EXISTS table_name; (Checks if the table exists before deleting)

DELETE (Delete Records)

DELETE FROM table_name WHERE field_name = "value";

Example: DELETE FROM table_name WHERE field_name = "delete to juan:";

WHERE Clause

SELECT * FROM table_name WHERE field_name > 1000;

AND and OR Operators

SELECT * FROM table_name WHERE field_name > 1000 OR (field < 500 AND field > 275);

BETWEEN Operator

SELECT * FROM table_

Read More

Data Types, Variables, Operators, and Structures in BASIC

Posted by on Feb 26, 2025 in Computers | 0 comments

Data Behavior in a Program

Data can behave in two different ways in a program:

  • Constants: Their value never changes during the program’s execution.
  • Variables: Their value can vary as often as necessary.

Naming Conventions

When naming a variable, keep in mind the following rules:

  • Any alphanumeric character can be used, but it must always begin with a letter.
  • Spaces are not allowed; it is common to use the underscore character (_) for compound names.
  • The name length may not exceed 32 characters.
  • Dots or other
Read More

Object-Oriented Design: Subsystems, Architecture, and MVC Pattern

Posted by on Feb 26, 2025 in Computers | 0 comments

Object-Oriented Design Steps

In object-oriented design, two major steps are needed to begin the design phase. These steps involve organizing the problem domain and subdividing it into packages with defined stereotypes.

When approaching the problem domain, the initial step is to partition the analysis model. This involves defining cohesive collections of classes, relationships, and behaviors, bundling them into packages or subsystems.

Important Considerations for Subsystems:

  • A subsystem must have a well-
Read More

Dart Streams and SQLite Database Management in Flutter

Posted by on Feb 26, 2025 in Computers | 0 comments

1. Single Subscription vs. Broadcast Streams

Single Subscription Streams

  • Allows only one listener at a time.
  • Ideal for sequential or one-time data processing, such as reading a file or fetching data from an API.
  • Example: File I/O operations or HTTP requests.

Broadcast Streams

  • Allows multiple listeners simultaneously.
  • Best for scenarios involving real-time data or event broadcasting, such as WebSocket updates or UI events.
  • Example: Button clicks or live data updates.

Code Example:

import 'dart:async';

void
Read More

Understanding Deadlock, Virtual Memory, and Disk Management

Posted by on Feb 25, 2025 in Computers | 0 comments

Deadlock Characterization

  • Mutual Exclusion: Only one process at a time can use a resource.
  • Hold and Wait: A process holding at least one resource is waiting to acquire additional resources held by other processes.
  • No Preemption: A resource can be released only voluntarily by the process holding it, after that process has completed its task.
  • Circular Wait: There exists a set {P0, P1, …, Pn} of waiting processes such that P0 is waiting for a resource that is held by P1, P1 is waiting for a resource
Read More

Machine and Assembly Language Differences

Posted by on Feb 25, 2025 in Computers | 0 comments

1)मशीनी भाषा एवं असेंबली भाषा में विभेद कीजिए।

=

मशीनी भाषा और असेंबली भाषा में विभेद

मशीनी भाषा और असेंबली भाषा दोनों ही कंप्यूटर प्रोग्रामिंग की निम्न-
स्तरीय भाषाएँ हैं, लेकिन उनमें कुछ महत्वपूर्ण

Read More