Category: SQL
34 posts
How to insert multiple rows in SQL ?
To insert multiple rows in SQL we can follow the below syntax:
INSERT INTO table_name (column1, column2,column3...)
VALUES
(value1, value2, value3…..),
(value1, value2, value3….),
... Read Mores
Prathmesh Yelne
16-Dec-2021 16:49:13
What is a Trigger in SQL?
A trigger in SQL is a special kind of stored procedure that automatically executes (or "fires") when specific actions occur in a database. Triggers are typically used to enforce business rules, data i... Read Mores
Prathmesh Yelne
04-Jul-2024 21:24:34
September 11, 2020
2.2 K Views
GCP Cloud Engineer
21 hours ago
What is SQL injection ?
SQL injection is a hacking technique which is widely used by black-hat hackers to steal data from your tables or databases. Let’s say, if you go to a website and give in your user information and pa... Read Mores
Prathmesh Yelne
04-Mar-2023 13:02:40
What is a unique key in SQL ?
Unique Key is a constraint in SQL. So, before understanding what exactly is a primary key, let’s understand what exactly is a constraint in SQL. Constraints are the rules enforced on data columns on... Read Mores
Prathmesh Yelne
16-Dec-2021 16:40:54
September 11, 2020
2.2 K Views
GCP Cloud Engineer
21 hours ago
How to delete a column in SQL ?
To delete a column in SQL we will be using DROP COLUMN method:
ALTER TABLE employees
DROP COLUMN age;
We will start off by giving the keywords ALTER TABLE, then we will give the name of the tab... Read Mores
Prathmesh Yelne
16-Dec-2021 16:39:14
What is a schema in SQL ?
Our database comprises of a lot of different entities such as tables, stored procedures, functions, database owners and so on. To make sense of how all these different entities interact, we would need... Read Mores
Prathmesh Yelne
16-Dec-2021 16:35:48
September 11, 2020
2.2 K Views
GCP Cloud Engineer
21 hours ago
What is OLTP ?
OLTP stands for Online Transaction Processing. And is a class of software applications capable of supporting transaction-oriented programs. An essential attribute of an OLTP system is its ability to m... Read Mores
Prathmesh Yelne
16-Dec-2021 16:30:58
What are Nested Triggers ?
Triggers may implement DML by using INSERT, UPDATE, and DELETE statements. These triggers that contain DML and find other triggers for data modification are called Nested Triggers.... Read Mores
Prathmesh Yelne
16-Dec-2021 16:29:11
September 11, 2020
2.2 K Views
GCP Cloud Engineer
21 hours ago
What are the types of SQL Queries ?
We have four types of SQL Queries:
DDL (Data Definition Language): the creation of objects
DML (Data Manipulation Language): manipulation of data
DCL (Data Control Language): assignment ... Read Mores
Prathmesh Yelne
19-Dec-2021 16:56:21
How can I see all tables in SQL?
Different database management systems have different queries to see all the tables.
To see all the tables in MYSQL, we would have to use this query:
show tables;
This is how we can see all t... Read Mores
Prathmesh Yelne
14-Dec-2021 17:13:39
September 11, 2020
2.2 K Views
GCP Cloud Engineer
21 hours ago