×

SQL Commands

SQL commands are classified into four groups on the basis of their nature.
  • DDL (Data Definition Language)
  • DML (Data Manipulation Language)
  • DCL (Data Control Language)
  • DQL (Data Query Language)
NOTE: This symbol ‘[ ] ‘indicates optional. SQL is not a case sensitive language.

Related Topics

SQL SELECT SUM

The SQL Sum() function is an aggregate function in SQL that returns the total values of an expression. The expression may be numerical, or it may be an expression. Syntax: SELECT SUM(columnname)...

3 minutes read.

Codd’s Rules in SQL

Codd’s Rules Dr. Edgar F. Codd, in 1985, laid down 13 fundamental rules after doing large-scale research on the Relational Model of databases. According to him, every database must follow these...

3 minutes read.

SQL Formatter

As a beginner, one does not focus much on Formatting the queries while writing their code. This leads to a great confusion while referring the code in future. For a...

5 minutes read.

SQL Right Join

The SQL Right Join query displays all the table records and similar records from the left table. The query display zero records if it doesn’t find any similar records. If...

4 minutes read.

How to Add Comments in SQL?

How to Add Comments in SQL Comments are text notes that are incorporated into the program to make the code easier to understand. In SQL, commenting is used to explain various sections...

2 minutes read.

Drop vs Truncate in SQL

In this article, we will learn and understand the Drop and Truncate commands and the difference between these two commands. What is Drop Command? Drop is a Data Definition Language command in...

6 minutes read.

SQL Insert multiple rows

This article will deal with a new insertion method in SQL which inserts multiple rows at a time. Multiple records can be inserted at a time into a specific table with...

4 minutes read.

How to delete a row in SQL

Introduction To delete or remove the unused/unwanted rows from a table, DELETE command is used in SQL.DELETE command removes the entire record from a table.The DELETE statement can delete one or...

6 minutes read.

SQL Injection

SQL injection is a technique, this may destroy the database. It is one type of hacking technique. SQL IN WEB PAGES: Injection occurs when we ask for input like an id or...

3 minutes read.

SQL Aliases

SQL Aliases: These are used to give a temporary name for a column or table. These are used to make tables or columns more readable. These are used to rename the table...

2 minutes read.

Nth highest salary

The most common and important question asked in interviews that how we can find the Nth highest salary in a table (2nd highest salary, 3rd highest salary, or Nth highest...

6 minutes read.

SQL SELECT MAX

The SQL Max() function is an aggregate function in SQL. This function returns the values which are greater in the condition. The condition may be a number, or it may...

5 minutes read.

SQL COPY Table

In this tutorial, we will learn how to copy tables in SQL with the help of examples. Using the SELECT INTO statement in the SQL we can copy one table into...

4 minutes read.

SQL Alter Table

In Structured Query Language, if you want to add columns in an existing table, then modify the table, or delete columns from the table. All these operations are allowed only...

7 minutes read.

How to use COUNT in SQL?

How to use COUNT in SQL Introduction COUNT( ) is an aggregate function in SQL.This function counts the number of records in a table if the condition is not specified.If the condition...

4 minutes read.

SQL Scalar Functions

TEACHER Table LCASE() Function The LCASE() function is used to return lower case values of specified column. Syntax: Select Lcase(column_name) from table_name; Example: Select Lcase(teacher_name) from teacher; Syntax: Select Lcase(column_name) from table_name [where condition]; Example: Select Lcase(teacher_name) from teacher where teacher_id=1; UCASE() Function The UCASE()...

1 minute read.

SQL TABLE

SQL TABLE Structured Query Language (SQL) is a relational database (RDBMS) where data is stored in the form of tables, that is, in rows and columns. These tables are known as...

3 minutes read.

How to delete column in table

Introduction In SQL, sometimes it is required to delete a column of a table.The use of ALTER TABLE command with DROP COLUMN clause will serve the purpose to delete/remove a column...

4 minutes read.

SQL WHERE Multiple Conditions

In this topic, we will learn how to add multiple conditions using the WHERE clause. First, let's understand the concept of WHERE clause. WHERE clause is used to specify a condition while...

5 minutes read.

SQL GROUP BY CLAUSE

The GROUP BY clause is used to arrange similar records into the groups in the Structured Query Language queries. The records are arranged with the help of functions which is...

4 minutes read.