SQL queries are the most common and essential SQL operations. Through an SQL query, you can search the database for a required information.
SQL Queries are executed with the “SELECT” statement. An SQL query can be more specific with the help of many clauses:
FROM- Indicates this table where it will be searched on.
WHERE – This is used to define rows, which will be searched in. All the rows for which WHERE clause is not true will be excluded.
ORDER BY – This is the only way to sort the result in SQL otherwise, they will return to a random order.
example of sql
SELECT * FROM
ORDER BY LastNme, FirstNme
Some of the most important SQL commands-
SELECT – extract data from the database.
UPDATE – Updates the data in the database.
DELETE – Deletes data from the database.
INSERT INTO – Injects new data to the database.
CREATE DATABASE – Creates a new database.
ALTER DATABASE – Modifies the database.
CREATE TABLE – Creates a new table.
ALTER TABLE – Tables modification
DROP TABLE – Deletes the table.
CREATE INDEX – creates an index (search key)
DROP INDEX – Deletes the index.