Database diagram support objects cannot be installed because this database does not have a valid owner. To continue, first use the Files page of the Database Properties dialog box or the ALTER AUTHORIZATION statement to set the database owner to a valid login, then add the database diagram support objects.

When I right click on the database diagrams folder in SSMS to create new diagram. Following popup window open with error.

Solutions:

From the Message you can clearly see that the database does not have a valid user. We can have a valid user by running a query or through SSMS.

Query:
ALTER AUTHORIZATION ON DATABASE::TestDB TO sa
GO

Change Database name to your database in query.

SSMS:
Go to properties of a Database by right clicking the Database and then select File.
Change the owner by clicking the dotted button in highlighted part in the image below.

Attach Database “Operating System Error 5 (Access is denied)” MSSQL Server 2012.

When I try to attach mdf file I got following error below.

Solution:

There are multiple solutions to this

1    1.    Move .mdf and .ldf to SQLServer install directory \Data\ folder (eg C:\Program Files (x86)\Microsoft SQL Server\MSSQL10.SQLEXPRESS\MSSQL\DATA) and then attach.
2    2. Give SQL SERVER SERVICE account full access to folder where mdf and ldf files are located.
3       3. Run as Administrator as in Below screens.

Run SSMS as admin as shown in screen below

Create Database Error "operating system error 112(There is not enough space on the disk.)"

I try to create database by generating script of another database, which was a huge Database. When I run the script below

USE [master]

GO

CREATE DATABASE [YourDB] ON  PRIMARY

( NAME = N'YourDB_1', FILENAME = N'G:\Data\YourDB.mdf' , SIZE = 230683968KB , MAXSIZE = UNLIMITED, FILEGROWTH = 10%),

 FILEGROUP [DWINDEX]

( NAME = N'YourDB_1_index', FILENAME = N'G:\Data\YourDB_1.ndf' , SIZE = 86941440KB , MAXSIZE = UNLIMITED, FILEGROWTH = 10%)

LOG ON

( NAME = N'YourDB_1_log', FILENAME = N'F:\Logs\SQL\YourDB_2.ldf' , SIZE = 2568128KB , MAXSIZE = 2048GB , FILEGROWTH = 10%),

( NAME = N'YourDB_2_log', FILENAME = N'F:\Logs\SQL\YourDB_3.ldf' , SIZE = 32256KB , MAXSIZE = 2048GB , FILEGROWTH = 1024KB ),

( NAME = N'YourDB_3_log', FILENAME = N'F:\Logs\SQL\YourDB_4.ldf' , SIZE = 19520KB , MAXSIZE = 2048GB , FILEGROWTH = 1024KB ),

( NAME = N'YourDB_31_log', FILENAME = N'F:\Logs\SQL\YourDB_5.ldf' , SIZE = 79488KB , MAXSIZE = 2048GB , FILEGROWTH = 10%)

GO

It  runs for almost half hour and return following error.

Error

Msg 5149, Level 16, State 3, Line 3

MODIFY FILE encountered operating system error 112(There is not enough space on the disk.) while attempting to expand the physical

file 'G:\Data\YourDB_1.ndf'.

Msg 1802, Level 16, State 4, Line 3

CREATE DATABASE failed. Some file names listed could not be created. Check related errors.

Solution:

When we create script of big Database, it goes to claim space at hard disk given in Size property of File and query took lot of time. Solution of the above query is quite simple, always set size property of mdf file to 4000KB and LDF file property to 1024KB to create new Database.