How to Retrieve Specific Records by SQL Database: SQL Server

By-default when user fire a query on the sql database it provides all the columns in the output, the table have. Database developer can change the no. of columns, to be displayed in the output. Sql Server Management Studio provides some special features explained in the article.

Retrieving Specific Attributes

While retrieving data from tables, you can display one or more columns. For example, the Adventure Works database stores the department details, such as Name and GroupName in the Department table. Users might want to view single column such as Name. Programmer can retrieve the required data from the database tables by using the SELECT statement.

The SELECT statement is used for accessing and retrieving data from a database. The syntax of the SELECT statement is:

SELECT [ALL | DISTINCT] select_column_list
[INTO [new_table_name]]
[FROM {table_name |view_name}
[WHERE search condition]

 

Where
  • ALL: represented with an (*) asterisk symbol and displays all the columns of the table.
  • Select_column_list: name of the table from which data is to be retrieved.
Note:
The SELECT statement can contains some more arguments such as WHERE, GROUP BY, COMPUTE, and ORDER BY that will be explained in later articles. All the examples in this SQL related articles are based on the Adventure Works Database, and can be download from here.
Consider the department table stored in the HumanResources schema of the Adventure Works database. To display all the detail of employees, you can use the following query:
 

SELECT * FROM HumanResources.Department
 

Execute the query and SQL Server will display the output of the query, as shown in the following figure.

How to Retrieve Specific Records by SQL Database: SQL Server 
The result set displays the records in the order in which they are stored in the table. In other words the records are sorted in ascending order of DepartmentId that is primary key of the department table.
   
Note:

The number of rows in the output window may vary depending on the modifications done on the database.
If you need to retrieve specific columns, you can specify the column names in the SELECT statement. For example, to view specific details, such as only Name of the employees of AdventureWorks, you can specify the column names in the SELECT statement, as shown in the following SQL query:
   
SELECT DepartmentId, Name FROM HumanResources.Department

The SQL Server will display the output of the query, as shown in the following figure.


How to Retrieve Specific Records by SQL Database: SQL Server 
In the output, the result set shows the column names the way they are present in the table definition. You can customize these column names, if required. As same as in above sql query you can specify some more columns as per the requirements.

Customizing and Concatening display in SQL Server

0 comments:

Post a Comment