Generic SQL Commands
=> Database has been installed according to https://www.hemelix.com/sql/sql-server-installation/
=> Database has been tested by running some of the example we have provided https://www.hemelix.com/sql/sql-data-modeling/
We need to make sure that SQL Server has been installed properly and also tested properly.
SQL aliases are used to give a table, or a column in a table, a temporary name. These are often used to make column names more readable. It only exists for the duration of that query which is created with the AS keyword.
Alias for Columns Examples:
We can assign new column name to existing column name.
Example, CustomerID will be as ID and CustomerName will be as Customer
SELECT CustomerID AS ID, CustomerName AS Customer
Alias for Tables Example:
Aliases are used to address database tables with a shorter or more meaningful name within an SQL query. The basic syntax of a table alias is as follows.
SELECT column1, column2....
FROM table_name AS alias_name
SELECT C.ID, C.NAME, C.AGE, O.AMOUNT
FROM CUSTOMERS AS C, ORDERS AS O
WHERE C.ID = O.CUSTOMER_ID;
SQL Variables in Queries
To make query, we can use parameters.