Question: I tried to solve this with logarithm rules:

O(n^2) = 2^O(log(n^2)) 

c\*n^2 = 2^log(n^2c)

Im not sure that is true?

Answer: 
Try with this Connectionstring:

```
<connectionStrings>
  <add name="DefaultConnection" connectionString="Data Source=(LocalDb)\v11.0;AttachDbFilename=D:\USERS\USERNAME\DOCUMENTS\TestDatabase\testdb.MDF;Initial Catalog=testdb;Integrated Security=True" providerName="System.Data.SqlClient" />
</connectionStrings>

```
```
PM>Update-Database

```

error and solution which I did today in 4 hours.
I am very much new in .net coding, but yes in PHP I have 10+ years experience.
It took me 4 hours to solve this.
1.My `first Mistake:` I was not having Microsoft SQL Server 2019 in my laptop locally I was having this through AZURE which is not works for localhost, so I installed this locally after download, it took around 2 Hours.
2.Second changed mistake=

```
 "DevConnection": "Server=localhost;Database=PaymentDetailDB;Trusted_Connection=True;MultipleActiveResultSets=True;"

```

then it works for me

[![Error](https://i.stack.imgur.com/o27EE.png)](https://i.stack.imgur.com/o27EE.png)

[![Error solution](https://i.stack.imgur.com/BUu02.png)](https://i.stack.imgur.com/BUu02.png)

[![Error solved](https://i.stack.imgur.com/AZNnU.png)](https://i.stack.imgur.com/AZNnU.png)
[![After error solved database](https://i.stack.imgur.com/eJzul.png)](https://i.stack.imgur.com/eJzul.png)