sql_basic_1.md

SQL Basics - 1 🚀👩‍🚀

- Data Manipulation Commands

• SELECT - used to retrieve data from a database example:

SELECT column1, column2, ...
FROM table_name;

• UPDATE - used to update existing data within a database example:

UPDATE table_name
SET column1 = value1, column2 = value2, ...
WHERE condition;

• DELETE - used to delete records from a database example:

DELETE FROM table_name
WHERE condition;

• INSERT INTO - used to insert new data into a database example:

INSERT INTO table_name (column1, column2, column3, ...)
VALUES (value1, value2, value3, ...);

• TRUNCATE TABLE - used to remove all records from a table, including all spaces allocated for the records are removed example:

TRUNCATE TABLE table_name;

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- Database Manipulation Commands

• CREATE DATABASE - used to create a new database example:

CREATE DATABASE database_name;

• ALTER DATABASE - used to modify a database example:

ALTER DATABASE database_name
MODIFY COLUMN column_name datatype;

• DROP DATABASE - used to delete a database example:

DROP DATABASE database_name;

• CREATE TABLE - used to create a new table example:

CREATE TABLE table_name (
    column1 datatype,
    column2 datatype,
    column3 datatype,
     ....
    );

• ALTER TABLE - used to modify a table example:

ALTER TABLE table_name
ADD column_name datatype;

• DROP TABLE - used to delete a table example:

DROP TABLE table_name;

• CREATE INDEX - used to create an index (search key) example:

CREATE INDEX index_name
ON table_name (column_name);

• DROP INDEX - used to delete an index example:

DROP INDEX index_name
ON table_name;

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