A primary key in MySQL is a unique identifier for each row in a table. It is used to identify a particular row in a table and ensure that each row is distinct from all other rows. It is typically a single column, but can also be composed of multiple columns.
For example, if you have a table of customers, you could use the customer ID as the primary key. This way, each customer will have a unique ID that can be used to identify them.
To delete data from a table in SQLite, you can use the DELETE statement.
For example, if you wanted to delete a row from the “Customers” table with the CustomerID of ‘123’, you could use the following SQL statement:
DELETE FROM Customers WHERE CustomerID = ‘123’;
You can update data in a SQLite table using the UPDATE statement.
For example, if you wanted to update the name of a customer in the “customers” table, you could execute the following SQL statement:
UPDATE customers
SET name = ‘John Smith’
WHERE customer_id = 123;
To insert data into a table in SQLite, you use the INSERT INTO statement.
For example, if you have a table called “customers” with the columns “name”, “address”, and “phone_number”, you can insert a new row into the table with the following statement:
INSERT INTO customers (name, address, phone_number) VALUES (‘John Doe’, ‘123 Main Street’, ‘555-123-4567’);
Vaibhav Kothia