SQL query questions and answers for practice

SQL Server is an interface that helps you communicate with the system’s database through queries. In this article, I will explain the ten best SQL queries. SQL queries are the mechanism of SQL to communicate with the database to result in the desired output.

Note: If you’re new here, we’ll start with these SQL articles first.

  1. How to download SQL server management studio 
  2. How to create a database in SQL
  3. How to create a table in SQL

Now we will start taking the most used 10 queries one by one.

1. INSERT INTO QUERY

We use the Insert Query or Command to insert data into a database table. The SQL INSERT INTO statement is used to include new database rows in the database table.

The syntax for the INSERT statement when inserting a single record with the VALUES keyword in SQL Server is.

The word VALUES is a keyword in SQL that is used to get the values of the columns. And the INSERT INTO is to insert the gated data into the database table.

Example:

In this example, I will show you how to add new customer data in the database.

After running this query, our table will look like this.

2. SELECT QUERY

The SQL SELECT statement is used to retrieve the data from a database table which returns this data in the form of a result table. These result tables are called results.

The basic syntax of the SQL SELECT statement is as follows:

Here are column1, column2 … the fields of a table whose values you want to retrieve. If you want to fetch all the available fields in the field, you can use the following syntax.

Example:

In this example, I will show you want to fetch all the fields of the STUDENT table, then you should use the following query.

The result of this query is a version of all rows in the table.

3. Update Records in a Table

The UPDATE statement is used to changes existing data in one or more rows in a table. The following represent
the syntax of the UPDATE statement.

The basic syntax of UPDATE query with WHERE member is as follows:

Example:

In this example, I will update the student name and age.

After running this query, our table will look like this.

4. Deleting Records From a Table

The SQL DELETE query is used to remove existing records from a table.

You can use the WHERE bypass with a DELETE query to delete the selected rows, otherwise all records will be deleted.

The basic syntax of the SQL DELETE query with the WHERE specifications as follows:

Example:

In this example, I will show you to Delete the one student Record in the database table.

After running this query, our table will look like this.

Thanks for reading! Share this article if you enjoyed it.

Leave a Reply