ER diagram - Are the relations and cardinalities correct? - postgresql

Question

I'm building a diagram on LucidChart for a Brewery that sells and makes beer in 1 location. I watched some videos on how to design an ER model. Wondering if this is correct or if I made any mistakes. Also what exactly is "mapping" for when talking about ER models?
Here is my ER model:
Also Cardinality Legend I went off of from LucidChart:

Answer 1

what exactly is "mapping" for when talking about ER models?
Within the context of a data model, the term "mapping" is a name for the process of converting a data model into the SQL DDL that can then be used to create a database schema in a database management system such as MySQL, SQL Server, Oracle and so on.
To the best of my knowledge, you can't "map" with tools such as Visio and LucidChart because these tools are not designed for data modeling. They are designed to mechanise the process of drawing diagrams. (A proper data model contains a lot more than pictures)
As an example, I used your ER diagram to design an object-role model using the free NORMA tool.The following diagrams show:
The object-role model
The logical model (It took a few milliseconds to generate the logical model from the object-role model.)
The SQL DDL that I "mapped" from the object-role model (It took a few seconds to map the object-role model into SQL DDL.)
I use SQL Server Management Studio so I can copy and paste the T-SQL version of the DDL into the "New Query" window and generate the database tables in a few seconds.
This is the object-role model (split into pages)
This is the logical model (auto generated) Note that unlike your model, there is only one "Address" table in the logical model.
This is the SQL DDL for MySQL Server (auto generated)
CREATE TABLE Brewery
(
breweryNr INT NOT NULL,
addressNr INT NOT NULL,
breweryName CHAR(63) NOT NULL,
CONSTRAINT Brewery_PK PRIMARY KEY(breweryNr)
);
CREATE TABLE Address
(
addressNr INT NOT NULL,
country CHAR(63) NOT NULL,
street CHAR(63) NOT NULL,
town CHAR(63) NOT NULL,
zipCode CHAR(63) NOT NULL,
CONSTRAINT Address_PK PRIMARY KEY(addressNr)
);
CREATE TABLE Beer
(
beerType CHAR(63) NOT NULL,
alcoholPercent INT NOT NULL,
beerAmountLitres CHAR(63) NOT NULL,
beerID CHAR(63) NOT NULL,
beerPrice CHAR(63) NOT NULL,
kegNr INT NOT NULL,
CONSTRAINT Beer_PK PRIMARY KEY(beerType)
);
CREATE TABLE BreweryMakesBeer
(
beerType CHAR(63) NOT NULL,
breweryNr INT NOT NULL,
CONSTRAINT BreweryMakesBeer_PK PRIMARY KEY(breweryNr, beerType)
);
CREATE TABLE Keg
(
kegNr INT NOT NULL,
kegState CHAR(63) NOT NULL,
CONSTRAINT Keg_PK PRIMARY KEY(kegNr)
);
CREATE TABLE Employee
(
employeeNr INT NOT NULL,
addressNr INT NOT NULL,
birthDate INT NOT NULL,
breweryNr INT NOT NULL,
firstName CHAR(63) NOT NULL,
lastName CHAR(63) NOT NULL,
salary DECIMAL(6,4) NOT NULL,
SSN CHAR(63) NOT NULL,
middleInt CHAR(63),
CONSTRAINT Employee_PK PRIMARY KEY(employeeNr)
);
CREATE TABLE Distributor
(
distributorNr INT NOT NULL,
brewingIngredientNr INT NOT NULL,
CONSTRAINT Distributor_PK PRIMARY KEY(distributorNr)
);
CREATE TABLE BrewingIngredient
(
brewingIngredientNr INT NOT NULL,
ingredientName CHAR(63) NOT NULL,
CONSTRAINT BrewingIngredient_PK PRIMARY KEY(brewingIngredientNr)
);
CREATE TABLE IngredientSupplier
(
ingredientSupplierNr INT NOT NULL,
addressNr INT NOT NULL,
CONSTRAINT IngredientSupplier_PK PRIMARY KEY(ingredientSupplierNr)
);
CREATE TABLE IngredientSupply
(
brewingIngredientNr INT NOT NULL,
ingredientSupplierNr INT NOT NULL,
CONSTRAINT IngredientSupply_PK PRIMARY KEY(brewingIngredientNr, ingredientSupplierNr)
);
ALTER TABLE Brewery ADD CONSTRAINT Brewery_FK FOREIGN KEY (addressNr) REFERENCES Address (addressNr) ON DELETE RESTRICT ON UPDATE RESTRICT;
ALTER TABLE Beer ADD CONSTRAINT Beer_FK FOREIGN KEY (kegNr) REFERENCES Keg (kegNr) ON DELETE RESTRICT ON UPDATE RESTRICT;
ALTER TABLE BreweryMakesBeer ADD CONSTRAINT BreweryMakesBeer_FK1 FOREIGN KEY (breweryNr) REFERENCES Brewery (breweryNr) ON DELETE RESTRICT ON UPDATE RESTRICT;
ALTER TABLE BreweryMakesBeer ADD CONSTRAINT BreweryMakesBeer_FK2 FOREIGN KEY (beerType) REFERENCES Beer (beerType) ON DELETE RESTRICT ON UPDATE RESTRICT;
ALTER TABLE Employee ADD CONSTRAINT Employee_FK1 FOREIGN KEY (breweryNr) REFERENCES Brewery (breweryNr) ON DELETE RESTRICT ON UPDATE RESTRICT;
ALTER TABLE Employee ADD CONSTRAINT Employee_FK2 FOREIGN KEY (addressNr) REFERENCES Address (addressNr) ON DELETE RESTRICT ON UPDATE RESTRICT;
ALTER TABLE Distributor ADD CONSTRAINT Distributor_FK FOREIGN KEY (brewingIngredientNr) REFERENCES BrewingIngredient (brewingIngredientNr) ON DELETE RESTRICT ON UPDATE RESTRICT;
ALTER TABLE IngredientSupplier ADD CONSTRAINT IngredientSupplier_FK FOREIGN KEY (addressNr) REFERENCES Address (addressNr) ON DELETE RESTRICT ON UPDATE RESTRICT;
ALTER TABLE IngredientSupply ADD CONSTRAINT IngredientSupply_FK1 FOREIGN KEY (brewingIngredientNr) REFERENCES BrewingIngredient (brewingIngredientNr) ON DELETE RESTRICT ON UPDATE RESTRICT;
ALTER TABLE IngredientSupply ADD CONSTRAINT IngredientSupply_FK2 FOREIGN KEY (ingredientSupplierNr) REFERENCES IngredientSupplier (ingredientSupplierNr) ON DELETE RESTRICT ON UPDATE RESTRICT;