Objectives of SQL

   
1).Ideally, database language should allow user to:-create the database and relation structures;perform insertion, modification, deletion of data from relations; perform simple and complex queries.

2).Must perform these tasks with minimal user effort and command structure/syntax must be easy to learn.

3).It must be portable.

4) SQL is a transform-oriented language with 2 major components:

•        DDL for defining database structure.
•        DML for retrieving and updating data.

   5).Until SQL3, SQL did not contain flow of control commands. These had to be implemented using a programming or jobcontrol language, or interactively by the decisions of user.

6).SQL is relatively easy to learn: it is non-procedural - you specify what information you require, rather than how to get it; it is essentially free-format.

   7).Consists of standard English words

•        CREATE TABLE Staff(staffNo VARCHAR(5), lName VARCHAR(15), salary DECIMAL(7,2));
     
•        INSERT INTO Staff VALUES (‘SG16Â’, ‘BrownÂ’, 8300);
       
•        SELECT staffNo, lName, salary FROM Staff WHERE salary > 10000;

   8).Can be used by range of users including DBAs, management, application developers, and other types of end users.

   9).An ISO standard now exists for SQL, making it both the formal and de facto standard language for relational databases.

Helpful link to know more about SQL : https://www.outsystems.com/evaluation-guide/using-sql-to-access-data/ 

https://success.outsystems.com/Documentation/11/Developing_an_Application/Use_Data/Query_Data/SQL_Queries  - outsystem Doc. link it will clearly explain about your query 

I hope this will help to you .............