I show examples working in database with SQL. Here I gave information about both reading and creating a database. I explained each step with comment lines.
All aggregate functions are deterministic. In other words, aggregate functions return the same value each time that they are called, when called with a specific set of input values.
DML is short name of Data Manipulation Language which deals with data manipulation and includes most common SQL statements such SELECT, INSERT, UPDATE, DELETE, etc., and it is used to store, modify, retrieve, delete and update data in a database.
DDL is short name of Data Definition Language, which deals with database schemas and descriptions, of how the data should reside in the database.
JOINS in SQL are commands which are used to combine rows from two or more tables, based on a related column between those tables. There are predominantly used when a user is trying to extract data from tables which have one-to-many or many-to-many relationships between them.
SQL Server Functions are useful objects in SQL Server databases. A SQL Server function is a code snippet that can be executed on a SQL Server
SQL Server stored procedure is a batch of statements grouped as a logical unit and stored in the database. The stored procedure accepts the parameters and executes the T-SQL statements in the procedure, returns the result set if any.
A SQL trigger is a database object which fires when an event occurs in a database. We can execute a SQL query that will "do something" in a database when a change occurs on a database table such as a record is inserted or updated or deleted. For example, a trigger can be set on a record insert in a database table