??

• ?????
• MySQL? ??? ?????? ?? ???(RDBMS)???. ???? ???? ???? ???? ??? ? ?? ?? ??, ?? ???, ?? ??? ?????? ??????. ??? ?? ??(SQL)? ???? ???? ???? ?????.

MySQL? ?? ??:

• ????
• ??? ???
• ??? ??????: MySQL? ???(????? ?)? ???? ???? ??? ?????? ??? ???? ???.
• ???: ??? ????? ?? ??? ???? ????? ??? ? ????.
• ACID ??: MySQL? ACID(???, ???, ??, ???) ??? ???? ?????? ????? ????? ????? ???.
  • ???? ????? ??? ? ?? ?? ??? ????? ?????. ???? ?? ?? ??? ????? ????? ?? ?? ???? ????. ?, ????? ??????. ?, "?? ??? ??"???.
  • ???? ????? ??????? ??? ??? ???? ?? ??? ??? ????? ?????. ?? ? ?? ???? ??? ?? ??, ?? ?? ? ??? ????? ??? ??? ???? ???.
  • ??? ?? ????? ??? ?????? ?? ???? ?????. ? ????? ?? ??? ????? ??? ????? ?? ????? ??? ??? ? ????.
  • ???? ?? ??? ????? ???? ??? ?? ??? ??? ???? ???? ????? ?????. ?????? ?? ?? ??? ???? ???? ?? ??? ?????? ?????.
• ?? ??? ???: MySQL? ???? ??? ??? ?? ?? ?? ???? ??? ??????? ???? ? ????.

SQL ???

???

1. ?????? ??
   • CREATE DATABASE ??? ? ??????? ???? ? ?????. Mongoose??? ??????? ????? ??? ??? ????. ??????? ??? ? ???? ?????.

// DB is created if it doesn't exist
mongoose.connect('mongodb://localhost/my_database');

CREATE DATABASE my_database;

1. ?????? ??
   • USE DB_NAME? ??? ??????? ???? ? ?????. Mongoose??? ?? ???? ?? ?????.

mongoose.connect('mongodb://localhost/my_database');

USE my_database;

1. ??? ???
   • CREATE TABLE ??? ??????? ? ???? ???? ? ?????. Mongoose?? ?? ? ???? ??? ?? ?????.

// DB is created if it doesn't exist
mongoose.connect('mongodb://localhost/my_database');

CREATE DATABASE my_database;

1. ?? ??
   • CREATE INDEX ??? ?? ??? ????? ?? ???? ???? ???? ? ?????. MongoDB??? ?? ?????.

mongoose.connect('mongodb://localhost/my_database');

USE my_database;

????

• SQL?? ???? ??(?? ?, ??? ??, ?? ?? ?)? ?? ? ?????. ??? ?: MongoDB?? DESCRIBE? ????? ??? ?? ????. ??? ????? ???? ???? ??? ? ????.

mongoose.model('User', UserSchema);

CREATE TABLE Users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(100) NOT NULL,
    email VARCHAR(100) NOT NULL UNIQUE
);

?? ??

• INSERT INTO ??? ???? ? ?? ???? ? ?????. ?????? ???/(??)? ? ??? ?????.

UserSchema.index({ email: 1 }); // Unnamed Index
UserSchema.index({ email: 1 }, { name: 'idx_email' }); // Named Index

-- Syntax: CREATE INDEX index_name ON table_name (column_name);
CREATE INDEX idx_email ON Users (email); -- Named Index
CREATE INDEX ON Users (email); -- Unnamed Index

????

• SQL? SELECT ?? ???????? ???? ???? ? ?????. Mongoose?? ?? .find() ???? ???? ???? ???? ?? ?????.

console.log(UserSchema.paths);
// Outputs details about the schema fields and types

DESCRIBE Users;

????

• UPDATE ?? ???? ?? ???? ???? ? ?????. ?????? find ? update ?? .update()? ?????.

// In mongoose its equivalent to .save() or .create();
const newUser = new User({ name: 'John Doe', email: 'john@example.com' });
newUser.save()

INSERT INTO Users (name, email)
VALUES ('John Doe', 'john@example.com');

??

• DELETE ?? ???? ?? ???? ???? ? ?????. ?????? deleteOne, deleteMany ?? find ? delete? ?????.

const users = await User.find(); // Fetches all users
const { name, email } = await User.findById(1); // Fetches user with id = 1

SELECT * FROM Users; -- all users
SELECT name, email FROM Users WHERE id = 1; -- user of id 1

???

• SQL? ALTER TABLE ?? ?? ???? ??? ???? ? ?????(? ??, ? ?? ? ? ??). Mongoose?? ??? ??? ? ??? ????? ???? ??? ?? ??? ?? ?? ??? ?? ????? ???? ????.

// update all user of name kb
const query = { name: "kb" };
User.update(query, { name: "thekbbohara" })

-- update all user of name kb
UPDATE Users
SET name = "thekbbohara", email = "thekbbohara@gmail.com"
WHERE name = "kb";

????

• JOIN ?? ? ? ??? ??? ??? ?? ?? ???? ? ? ??? ??? ?? ???? ? ?????. MongoDB??? ??? ???????? ??? ????? ???? ????. ?? ??? ??? ?? ????? $lookup? ?? ?? ?????? ?????.

User.deleteOne({ _id: 1 })
// All users whose name is notKb will be deleted.
User.deleteMany({ name: "notKb" })

?? ??

• INNER JOIN ???? ? ??? ???? ???? ?? ?? ???? ?????.

DELETE FROM Users WHERE id = 1;
DELETE FROM Users WHERE name = "notKb"
-- All users whose name is notKb will be deleted.

?? ??

• LEFT JOIN ???? ?? ???(table1)? ?? ???? ???? ??? ???(table2)?? ???? ???(?? ??)? ?????.

// Update the UserSchema to add the 'age' field
const UserSchema = new mongoose.Schema({
    name: String,
    email: String,
    age: Number, // New field
});

?? ??

• RIGHT JOIN ???? ??? ???(table2)? ?? ???? ?? ???(table1)? ???? ???(?? ??)? ?????.

-- Adds an 'age' column to the Users table
ALTER TABLE Users ADD age INT;

-- Delete 'Email' column from Users table
ALTER TABLE Users DROP COLUMN email;

-- Makes 'id' column unsigned and auto-incrementing
ALTER TABLE Users MODIFY COLUMN id INT UNSIGNED AUTO_INCREMENT;

?? ??

• CROSS JOIN ???? ? ???(table1 ? table2)? ?? ???? ?????.

// DB is created if it doesn't exist
mongoose.connect('mongodb://localhost/my_database');

??? ??

MySQL?? ???, ??, ?? ? ??? ? ?? ?? ??? ??? ????. ??? MongoDB?? ??? ??? ??? ??? MySQL? ??? ???? ????. MongoDB? ??? ??? ?? ??? ???? BSON(Binary JSON)? ???? ???? ?????. ??? MySQL? MongoDB? ???? ??? ??? ??? ????.

??? ??? ??

?? ??? ??

?? ? ?? ??? ??

?? ??? ??

???? ??? ??

JSON/?? ??? ??

?? ??? ??

?? ?

• ???? ? ?? ?? ???? ??? ?????.

// DB is created if it doesn't exist
mongoose.connect('mongodb://localhost/my_database');

CREATE DATABASE my_database;

?? ?

• ?? ?? ?? ???? ?? ????? ?????.

mongoose.connect('mongodb://localhost/my_database');

USE my_database;

??? ??? ? ??

1. NULL? ??: ?? NULL ?? ?? ? ??? ???.

mongoose.model('User', UserSchema);

CREATE TABLE Users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(100) NOT NULL,
    email VARCHAR(100) NOT NULL UNIQUE
);

1. ???: ?? ?? ?? ???? ?????.

UserSchema.index({ email: 1 }); // Unnamed Index
UserSchema.index({ email: 1 }, { name: 'idx_email' }); // Named Index

-- Syntax: CREATE INDEX index_name ON table_name (column_name);
CREATE INDEX idx_email ON Users (email); -- Named Index
CREATE INDEX ON Users (email); -- Unnamed Index

1. ???: ?? ???? ??? ?? ???? ?????.

console.log(UserSchema.paths);
// Outputs details about the schema fields and types

DESCRIBE Users;

1. ??(MySQL 8.0): ?? ?? ??? ??? ????? ?????.

// In mongoose its equivalent to .save() or .create();
const newUser = new User({ name: 'John Doe', email: 'john@example.com' });
newUser.save()

INSERT INTO Users (name, email)
VALUES ('John Doe', 'john@example.com');

1. ?? ??: ?? ?? ?? ???? ?? ?? ?? ???? ?????.

const users = await User.find(); // Fetches all users
const { name, email } = await User.findById(1); // Fetches user with id = 1

SELECT * FROM Users; -- all users
SELECT name, email FROM Users WHERE id = 1; -- user of id 1

?? ????. ??? ????. ???? ???? ?????. thekbbohara

? ??? ???? ? ????.

?, ??? Mysql? ??? ??????
Docker ??? ?????.

// update all user of name kb
const query = { name: "kb" };
User.update(query, { name: "thekbbohara" })

-- update all user of name kb
UPDATE Users
SET name = "thekbbohara", email = "thekbbohara@gmail.com"
WHERE name = "kb";

? ??? ??? ???? ?? MySQL.? ?? ?????. ??? ??? PHP ??? ????? ?? ?? ??? ?????!