Knowledge Search

Find SQL tutorials, syntax, and reference posts.

What is T-SQL

Hi! Before diving into T-SQL, make sure to check our post on What is MSSQL? for a comprehensive overview. In this tutorial, we'll explore the essence of T-SQL, MS-S…

Download SQL Server

SQL Server, a powerful relational database management system (RDBMS) meticulously crafted by Microsoft, stands as a cornerstone in managing and organizing structure…

What is SQL

SQL is a powerful programming language utilized for managing and manipulating relational databases. This chapter will cover the fundamentals, exploring the concepts…

Download database

[AdventureWorks] is a sample database used for learning and testing that was originally created by Microsoft for demonstration purposes.

Restore database

Restoring an SQL database involves taking a backup of the database, and then restoring it into a SQL Server instance.

Install SQL Server

1. Download the SQL Server installer from the Microsoft website. You can choose between the Developer, Express, or Evaluation edition depending on your needs. After…

Download SQL Server Management Studio SSMS

SSMS is an integrated development environment (IDE) used to manage and administer Microsoft SQL Server, providing a variety of features and tools for developers and…

SQL Server Management Studio

SQL Server Management Studio (SSMS) is an integrated development environment (IDE) used to manage and administer Microsoft SQL Server, providing a variety of featur…

Backup database

Backing up a SQL database is an important task and is the process of creating a copy of data to ensure the availability and recoverability of data in case of system…

Attach database

SQL database attaching is the process of connecting an existing "database file" to SQL server database instance.

Detach database

SQL database detaching is the process of removing the database from the SQL Server instance without deleting the database files from the disk.

Create database

Creating SQL database refers to the the process of defining and adding a new database instance that is managed by a database management system (DBMS) using SQL comm…

Delete database

Deleting SQL database refers to the process of deleting/removing the entire database permanently from the database server and it can not be undone. "DROP DATABASE" …

Rename database

Renaming SQL database refers to the process of changing the name of an existing database to a new name. "ALTER DATABASE" command is used to change the properties of…

Select database

The "USE" command is a powerful tool that allows to switch to a specific database in order to use it to perform operations in SQL. You can easily navigate to a part…

Database offline

When SQL Server database is offline, it means the database is temporarily unavailable and cannot be accessed for use by any application or user until it is brought …

Database online

When SQL Server database is online, it means the database is available and can be accessed for use by any application or user unless it is taken to offline.

SQL Commands

Understanding SQL command is essential for working with databases. SQL command allows user to retrieve, manipulate, and manage data stored in the databases. It incl…

SQL Data Types

A data type is like a tag that tells the computer what kind of data/information it's dealing with. It helps computers to manage data effectively and in a structured…

SQL Comments

SQL comment is a text, added to the code to provide information about what the code is doing. Comment is ignored by the SQL engine when the code is run. The purpose…

SQL Tables

SQL table is a database object that organize and stores data in a structured manner. It uses rows and columns to organize data, where each row represents a unique r…

Create table

Creating an SQL table refers to the process of defining and adding a new table to an existing database instance. SQL table is made up of one or more columns, each o…

Rename table

Renaming SQL table refers to the process of changing the name of an existing table to a new name.

Select table

Selecting SQL table refers to the process of retrieving data from table(s). SQL stores data in a tabular format with rows and columns. You can use the "SELECT" stat…

Delete table

Deleting SQL table refers to the process of deleting/removing the entire table permanently, including its structure and any data it contains from the database and i…

SQL Database

Database is a collection of data that is organized and stored in a way that makes it easy to manage and manipulate. A database consists of one or more tables, which…

SQL Constraints

SQL constraint is a rule applied to the 'column(s)', that restricts the values that can be entered into that column(s).

SQL Joins

SQL join is a technique used to combine two or more tables data by using a common column or key. It allows you to retrieve data from multiple tables based on a rela…

SQL inner join

INNER JOIN(or JOIN) returns only the matching rows between two tables. By default 'JOIN' keyword is treated as 'INNER JOIN'.

SQL left join

LEFT JOIN (or LEFT OUTER JOIN) returns all the rows from the left table and the matching rows from the right table. If there is no match, the result will have null …

SQL right join

RIGHT JOIN (or RIGHT OUTER JOIN) returns all the rows from the right table and the matching rows from the left table. If there is no match, the result will have nul…

SQL full join

FULL JOIN (or FULL OUTER JOIN) returns all the rows from both tables, with null values for the columns that do not have a match in the other table.

SQL cross join

CROSS JOIN combines each row from one table with every row from another table. Typically, it is used to generate all possible combinations of rows from two or more …

SQL self join

SELF JOIN is the type of join, where a table is joined with itself as if it were two separate tables. It is useful where a table contains hierarchical data or when …

Truncate table

Truncating SQL table refers to the process of deleting all table data quickly without affecting the table structure and without logging individual deletions. "TRUNC…

INSERT INTO statement

To insert data into an existing SQL table, you can use "INSERT INTO" statement which insert new rows of data into an existing table.

Alter table

Altering SQL table refers to the process of modifying the structure of an existing table in the database.

INSERT INTO SELECT statement

You can use "INSERT INTO" with "SELECT" statement to copy or transfer data between SQL tables.

SQL Clauses

SQL clause is the specific part of a SQL statement which is used to perform various operations. It is used to filter, retrieve, group, sort, join and manipulate dat…

SELECT clause

SQL clause is the specific part of a SQL statement which is used to perform various operations. It can be combined to create more complex queries to retrieve and ma…

FROM clause

SQL clause is the specific part of a SQL statement which is used to perform various operations. It can be combined to create more complex queries to retrieve and ma…

WHERE clause

SQL clause is the specific part of a SQL statement which is used to perform various operations. It can be combined to create more complex queries to retrieve and ma…

GROUP BY clause

SQL clause is the specific part of a SQL statement which is used to perform various operations. It can be combined to create more complex queries to retrieve and ma…

HAVING clause

SQL clause is the specific part of a SQL statement which is used to perform various operations. It can be combined to create more complex queries to retrieve and ma…

ORDER BY clause

SQL clause is the specific part of a SQL statement which is used to perform various operations. It can be combined to create more complex queries to retrieve and ma…

JOIN clause

SQL clause is the specific part of a SQL statement which is used to perform various operations. It can be combined to create more complex queries to retrieve and ma…

UNION clause

SQL clause is the specific part of a SQL statement which is used to perform various operations. It can be combined to create more complex queries to retrieve and ma…

UNION ALL clause

SQL clause is the specific part of a SQL statement which is used to perform various operations. It can be combined to create more complex queries to retrieve and ma…

TOP clause

SQL clause is the specific part of a SQL statement which is used to perform various operations. It can be combined to create more complex queries to retrieve and ma…

DISTINCT clause

SQL clause is the specific part of a SQL statement which is used to perform various operations. It can be combined to create more complex queries to retrieve and ma…