#Create a table
Syntax: CREATE TABLE table_name (column1 datatype, column2 datatype,...);
Primary Keys
eg
CREATE TABLE Users (
UserID INT PRIMARY KEY,
FirstName VARCHAR(50),
LastName VARCHAR(50),
Email VARCHAR(100) UNIQUE,
Birthdate DATE
);
#Select from a table
SELECT column1, column2 FROM table_name WHERE condition;
eg
SELECT FirstName, LastName, Email
FROM Users
WHERE Birthdate >= '1990-01-01';
#Insert into
INSERT INTO table_name (column1, column2, ...) VALUES (value1, value2,...);
eg
INSERT INTO Users (FirstName, LastName, Email)
VALUES ('John', 'Doe', '[email protected]');
#Update table
UPDATE table_name SET column1 = value1, column2 = value2 WHERE condition;
eg
UPDATE Users
SET LastName = 'Smith', Email = '[email protected]'
WHERE UserID = 1;
#Delete table
DELETE FROM table_name WHERE condition;
eg
DELETE FROM Users WHERE UserId = 1;
#Table with Reference
CREATE TABLE Orders (
OrderID INT PRIMARY KEY,
ProductID INT,
-- Other order-related columns
FOREIGN KEY (ProductID) REFERENCES Products(ProductID)
);
#Creating an [[Indexes | Index]]
CREATE INDEX idx_LastName ON Employees(LastName);
#Creating a [[Transactions | Transaction]]
BEGIN TRANSACTION;
-- SQL statements here (INSERT, UPDATE, DELETE, etc.)
COMMIT;
Primary Keys