PHP Course For Beginners > MY SQL with PHP

SQL constraints

51.2k

SQL constraints are rules that a table's data must follow. The type of data that can be entered into a table is limited by constraints. This ensures that the data in the table is accurate and reliable. The action is cancelled if there is a conflict between the constraint and the data action.

When no value is supplied for a column, the DEFAULT Constraint provides a default value. UNIQUE Constraint ensures that every value in a column is unique. Each row/record in a database table is uniquely identified by the PRIMARY Key. FOREIGN KEY identifies a row/record in any database table in a unique way.

A constraint is defined as something that imposes a limit or restriction on something or prohibits something from happening. The fact that there are only so many hours in a day to complete something is an example of a restriction. A check is a device that restricts, limits, or regulates something.

Constraints are required for developing respect for other people's opinions and beliefs. It is required for the development of a society. Absence of restraint would result in the imposition of stronger groups' views and ideas, eventually leading to war. Controlling violence and resolving conflicts necessitates the use of constraints.

Constraints are used to ensure data integrity when updating, deleting, or inserting data into a table. If any operation in the database does not follow the rules stated by the constraint after it is placed, the operation is aborted.

Learner's Ratings

4.2

Overall Rating

  • 63%
  • 21%
  • 7%
  • 5%
  • 4%

Reviews

P
Pranoy Acharyya
4

Increase the sound and stop repeating

M
Mr SURYAVANSHI
5

very bad lecture bahut bekar class de raha hai, bar bar right right karke kan paka diya hai confidence nhi hai class dene ka khud hi phle class karke trend ho jao itna bor kar diya inhone.

B
Boobalan A
5

I want this course for english. Classes are superb. but not understand few places, because I don't know hindi.

A
abhay
5

best course

A
Anish Narang
5

Best Course in Market till now

N
Nitish Kumar Sharma
4

Meet Shah is the worst teacher i have found in learnvern platform please replace his video with some other teacher he is unable to explain concept properly and sometimes he explain concept incorrect.

S
Sonu sonu
5

very good

I
Islam Web
5

Nice

R
Ravi Ranjan Tiwari
5

I am very happy that I am studying from LearnVern.

M
Muhammad Talha
5

help full.

Show More
Recommended Courses
Course Content

  1. Introduction to PHP
    10m 23s
  2. Understanding SDLC Process
    13m 58s
  3. How to use LearnVern
    3m 20s
  4. Client Server Architecture
    5m 18s
  5. How to set up PHP Environment?
    18m 6s

  1. What is Data
    8m 57s
  2. What is Database
    3m 25s
  3. What is DBMS
    14m 25s
  4. SQL Queries and its types
    16m 57s
  5. Data Types in SQL - from 16
    22m 41s
  6. SQL constraints
    10m 52s
  7. Create, Drop & Show Database
    13m 40s
  8. SQL Create Table
    13m 53s
  9. SQL Insert & Select Statement
    26m 56s
  10. Operators in SQL
    6m 47s
  11. In & NOt in Condition
    7m 4s
  12. Null & Not Null Condition
    4m 55s
  13. Clauses in SQL
    9m 46s
  14. Understanding Having, Distinct & Group by
    21m 54s
  15. Update & Delete in SQL
    12m
  16. Alter table command in SQL
    15m 29s
  17. MySQL Rename truncate Drop
    6m 34s
  18. Understanding Foreign key
    15m 37s
  19. MySQL joins
    22m 56s
  20. MySQL views
    18m 23s
  21. MySQL Function
    21m 39s
  22. MySQL Procedure
    15m 33s
  23. MySQL Trigger
    16m 15s
  24. Normalization
    16m 9s
  25. Assignment : MYSQL
    8m 56s

  1. Understanding HTTP Methods
    33m 26s

  1. Understanding PHP Program structure Comments in PHP
    13m 7s

  1. Variables in PHP
    11m 46s

  1. Arithmetic & Assignment Operators in PHP
    24m 28s
  2. Comparison & Logical Operators in PHP
    33m 17s
  3. Ternary Operator in PHP
    14m 38s
  4. Assignment : Operators
    1m 22s

  1. Super Global Variable in PHP
    19m 30s
  2. GET & POST Variable in PHP
    12m 21s
  3. $_FILES & $_ENV in PHP
    15m 24s
  4. Assignment : Super Global Variables
    2m 16s

  1. If-else in PHP
    26m 25s
  2. switch case in PHP
    15m 2s
  3. Assignment : Conditional Statements
    2m 28s

  1. Functions in PHP
    39m 46s
  2. Call by value vs Call by reference in PHP
    17m 28s
  3. Assignment : Functions
    5m 25s

  1. Array Functions in PHP
    44m 28s
  2. Array in PHP
    19m 35s
  3. Assignment : Array
    7m 18s

  1. String and its Functions in PHP
    27m 53s
  2. Assignment : String
    3m 44s

  1. Loops in PHP
    19m 28s
  2. More examples on Loops in PHP
    17m 20s
  3. Assignment : Loops
    8m 32s

  1. Cookies in PHP
    15m 45s
  2. Session in PHP
    35m 42s

  1. Header Function in PHP
    17m 11s
  2. Assignment : Header Functions
    1m 57s

  1. Date and Time functions in PHP
    36m 14s
  2. Assignment : Date Time Functions
    4m 29s

  1. Include & Require Statement in PHP
    13m 52s

  1. Error Handling in PHP
    15m 18s

  1. File Upload in PHP
    42m 55s

  1. Database Connection in PHP Part 1
    29m 17s
  2. Database Connection in PHP Part 2
    32m

  1. SQL Injection in PHP
    30m 33s

  1. Crud - Registration and DB connection Part 1
    31m 31s
  2. Crud - Registration and DB connection Part 2
    24m 2s
  3. Log in Operation
    27m 24s
  4. Read Operation
    30m 27s
  5. Update Operation Part 1
    12m 53s
  6. Update Operation Part 2
    27m 17s
  7. Log out Operation
    9m 29s

  1. MySQL Interview Question 1
    33m 7s
  2. MySQL Interview Question 2
    25m 23s
  3. MySQL Interview Question 3
    24m 27s
Enroll For Free