Here i will be explaining how we can create database in .net framework itself without using SQL Server database. For this please follow below written steps-
1. Right click on website/solution folder in solution explorer and select Add new item from that.
2.Select Database file from that and give some name. It will have extension as .mdf.
3.now your database has been created with the name (suppose abc.mdf).
4. Now open database explorer and there you will find the abc.mdf, open it and right click on table and add new table. Here you can create your table and save it. While saving it will ask for the table name give that and save.
5. Now create connection string as the below-
<add name="conn" connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\abc.mdf;Integrated Security=True;User Instance=True" providerName="System.Data.SqlClient"/>
6. Now you can do all the connection as you are doing in sql server.