On my local machine, I am unable to drop a table because it doesn't exist or I don't have permission - sql-server

Question

I am going through college and I'm doing an database class where we're introduced to the SQL Server Management Studio, so I'm very new to all of this. That being said, I've been following along and keeping up, making sure to note his queries... However, I noticed something. In the queries I've been making while keeping notes of my class, I have the error "cannot drop table because it does not exist or you don't have permissions".
Now this is odd to me, as I am the only user of this laptop, I am basically the administrator, I've created the database and tables as per instructions and yet, this issue is popping up and I'm unable to run my queries to see how they work.
Here's a snippet of my code, though I'm not sure how much it'd help...
-- Dropping tables in case they already exist
drop table Movie
drop table Genre
drop table Theater
drop table MovieTheater
-- Create table
create table Movie
(
MovieID int not null constraint PK_Movie primary key,
Title varchar(200) not null,
Budget money null,
ReleaseDate date null,
GenreCode char(1) not null constraint FK_MovieToGenre references Genre(GenreCode),
Released bit not null,
MovieLength decimal(5,2) null
)
create table Genre
(
GenreCode char(1) not null constraint PK_Genre primary key,
GenreDescription varchar(30) not null
)
create table Theater
(
TheaterID int not null constraint PK_Theater primary key,
TheaterName varchar(100) not null,
Address varchar(50) not null,
City varchar(50) not null,
Province char(2) not null,
PostalCode char(7) not null,
PhoneNumber char(13) not null
)
create table MovieTheater
(
MovieID int not null,
TheaterID int not null,
StartDate date not null,
EndDate date null,
constraint PK_MovieTheater primary key (MovieID, TheaterID)
)
I attempted changing the permissions of the database but it wouldn't allow me. Other solutions I've looked up all assume that it's connecting to a database for other purposes (likely work related)

Answer 1

The error is pretty clear. cannot drop table because it does not exist. You can't DROP a table that doesn't exist, just as you can't CREATE a table that already exists.
In SQL Server 2016 and later you can use DROP TABLE IF EXISTS to drop a table if it exists. Since the oldest version in mainstream support is SQL Server 2019, you can reasonably expect that IF EXISTS will work on any new database
DROP TABLE IF EXISTS [dbo].[MyTable0];
In older, now unsupported, versions you had to check explicitly in an IF :
IF OBJECT_ID(N'dbo.MyTable0', N'U') IS NOT NULL
DROP TABLE [dbo].[MyTable0];
The SQL Server DROP TABLE IF EXISTS Examples shows all these options. Use DROP TABLE IF EXISTS unless you really need to work with an unsupported database version.

Answer 2

From your code, I think the problem is you tried to drop the tables before you created them
-- Dropping tables in case they already exist
drop table Movie
drop table Genre
drop table Theater
drop table MovieTheater
To drop the table if only it has already exist, you could try:
IF OBJECT_ID('tableName', 'U') IS NOT NULL
DROP TABLE tableName;
Explain:
The OBJECT_ID function returns the object ID of the specified table. If the table does not exist, it returns NULL. The 'U' parameter indicates that we are looking for a user-defined table.
The IF statement checks whether the table exists by checking the result of the OBJECT_ID function. Simple as that!