Update schema.sql

SQL/schema.sql

@@ -1,74 +1,76 @@
--- Exported from QuickDBD: https://www.quickdatabasediagrams.com/
+-- Exported from QuickDBD: https://www.quickdatabasediagrams.com/
 -- Link to schema: https://app.quickdatabasediagrams.com/#/d/s8Wnqm
 -- NOTE! If you have used non-SQL datatypes in your design, you will have to change these here.
 
---Card Holder
+-- Card Holder Table
 
 CREATE TABLE "card_holder" (
-    "id" SERIAL   NOT NULL,
-    "name" VARCHAR(50)   NOT NULL,
-    CONSTRAINT "pk_card_holder" PRIMARY KEY (
-        "id"
-     )
+    "id" SERIAL NOT NULL,
+    "name" VARCHAR(50) NOT NULL,
+    CONSTRAINT "pk_card_holder" PRIMARY KEY ("id")
 );
 
--- Credit Card
+-- Credit Card Table
 
 CREATE TABLE "credit_card" (
-    "card" VARCHAR(20)   NOT NULL,
-    "id_card_holder" INT   NOT NULL,
-    CONSTRAINT "pk_credit_card" PRIMARY KEY (
-        "card"
-     )
+    "card" VARCHAR(20) NOT NULL,
+    "id_card_holder" INT NOT NULL,
+    CONSTRAINT "pk_credit_card" PRIMARY KEY ("card")
 );
 
--- Merchant
+-- Merchant Table
 
 CREATE TABLE "merchant" (
-    "id" SERIAL   NOT NULL,
-    "name" VARCHAR(255)   NOT NULL,
-    "id_merchant_category" INT   NOT NULL,
-    CONSTRAINT "pk_merchant" PRIMARY KEY (
-        "id"
-     )
+    "id" SERIAL NOT NULL,
+    "name" VARCHAR(255) NOT NULL,
+    "id_merchant_category" INT NOT NULL,
+    CONSTRAINT "pk_merchant" PRIMARY KEY ("id")
 );
 
--- Merchant Category
+-- Merchant Category Table
 
 CREATE TABLE "merchant_category" (
-    "id" SERIAL   NOT NULL,
-    "name" VARCHAR(50)   NOT NULL,
-    CONSTRAINT "pk_merchant_category" PRIMARY KEY (
-        "id"
-     )
+    "id" SERIAL NOT NULL,
+    "name" VARCHAR(50) NOT NULL,
+    CONSTRAINT "pk_merchant_category" PRIMARY KEY ("id")
 );
 
--- Transaction
+-- Transaction Table
 
 CREATE TABLE "transaction" (
-    "id" INT   NOT NULL,
-    "date" TIMESTAMP   NOT NULL,
-    "amount" FLOAT   NOT NULL,
-    "card" VARCHAR(20)   NOT NULL,
-    "id_merchant" INT   NOT NULL,
-    CONSTRAINT "pk_transaction" PRIMARY KEY (
-        "id"
-     )
+    "id" INT NOT NULL,
+    "date" TIMESTAMP NOT NULL,
+    "amount" FLOAT NOT NULL,
+    "card" VARCHAR(20) NOT NULL,
+    "id_merchant" INT NOT NULL,
+    CONSTRAINT "pk_transaction" PRIMARY KEY ("id")
 );
 
-
-ALTER TABLE "credit_card" ADD CONSTRAINT "fk_credit_card_id_card_holder" FOREIGN KEY("id_card_holder")
+-- Add Foreign Key Constraint to Credit Card Table
+ALTER TABLE "credit_card" 
+ADD CONSTRAINT "fk_credit_card_id_card_holder" 
+FOREIGN KEY("id_card_holder") 
 REFERENCES "card_holder" ("id");
 
-ALTER TABLE "credit_card" ADD CONSTRAINT "check_credit_card_length"  CHECK (char_length("card") <= 20);
-
---ALTER TABLE "credit_card" DROP CONSTRAINT check_credit_card_length
+-- Add Check Constraint to Credit Card Table for Card Length
+ALTER TABLE "credit_card" 
+ADD CONSTRAINT "check_credit_card_length" 
+CHECK (char_length("card") <= 20);
 
-ALTER TABLE "merchant" ADD CONSTRAINT "fk_merchant_id_merchant_category" FOREIGN KEY("id_merchant_category")
+-- Add Foreign Key Constraint to Merchant Table
+ALTER TABLE "merchant" 
+ADD CONSTRAINT "fk_merchant_id_merchant_category" 
+FOREIGN KEY("id_merchant_category") 
 REFERENCES "merchant_category" ("id");
 
-ALTER TABLE "transaction" ADD CONSTRAINT "fk_transaction_card" FOREIGN KEY("card")
+-- Add Foreign Key Constraint to Transaction Table for Card
+ALTER TABLE "transaction" 
+ADD CONSTRAINT "fk_transaction_card" 
+FOREIGN KEY("card") 
 REFERENCES "credit_card" ("card");
 
-ALTER TABLE "transaction" ADD CONSTRAINT "fk_transaction_id_merchant" FOREIGN KEY("id_merchant")
-REFERENCES "merchant" ("id");
+-- Add Foreign Key Constraint to Transaction Table for Merchant
+ALTER TABLE "transaction" 
+ADD CONSTRAINT "fk_transaction_id_merchant" 
+FOREIGN KEY("id_merchant") 
+REFERENCES "merchant" ("id");