ER to relational mapping

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Q2

how to compares two dates and returns the difference in apex?!

using booking table

you have 3 tables call

booking - cars - cars_category

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Q1)

create table call RENT and select car regestration number and category number from Cars table

and select cost per day from cars category number

make cars category join cars table

On cars category.cat_number = cars.cat_number

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Q2)

create table call Results and

select car regestration number from booking

and display the cost per day from Rent table to compare the diffrent from two dates (booking date, return date)

Table: CARS (?) \begin{tabular}{|l|l|l|l|l|l|} \hline \multicolumn{1}{|c|}{ Column } & Data Type & Length & Precision & Scale & Nullable \\ \hline CAR_REGESTRATION_NUM & NUMBER & 22 & & & No \\ \hline C_TYPE & VARCHAR2 & 30 & & & Yes \\ \hline MODEL_YEAR & NUMBER & 22 & & & No \\ \hline BRAND_NAME & VARCHAR2 & 20 & & & No \\ \hline MILEAGE & NUMBER & 22 & & & No \\ \hline CAT_NUM & NUMBER & 22 & & & Yes \\ \hline \end{tabular} Table: CARS (?) \begin{tabular}{|l|l|l|l|l|l|} \hline \multicolumn{1}{|c|}{ Column } & Data Type & Length & Precision & Scale & Nullable \\ \hline CAR_REGESTRATION_NUM & NUMBER & 22 & & & No \\ \hline C_TYPE & VARCHAR2 & 30 & & & Yes \\ \hline MODEL_YEAR & NUMBER & 22 & & & No \\ \hline BRAND_NAME & VARCHAR2 & 20 & & & No \\ \hline MILEAGE & NUMBER & 22 & & & No \\ \hline CAT_NUM & NUMBER & 22 & & & Yes \\ \hline \end{tabular} Table: CARS (?) \begin{tabular}{|l|l|l|l|l|l|} \hline \multicolumn{1}{|c|}{ Column } & Data Type & Length & Precision & Scale & Nullable \\ \hline CAR_REGESTRATION_NUM & NUMBER & 22 & & & No \\ \hline C_TYPE & VARCHAR2 & 30 & & & Yes \\ \hline MODEL_YEAR & NUMBER & 22 & & & No \\ \hline BRAND_NAME & VARCHAR2 & 20 & & & No \\ \hline MILEAGE & NUMBER & 22 & & & No \\ \hline CAT_NUM & NUMBER & 22 & & & Yes \\ \hline \end{tabular} Table: CARS (?) \begin{tabular}{|l|l|l|l|l|l|} \hline \multicolumn{1}{|c|}{ Column } & Data Type & Length & Precision & Scale & Nullable \\ \hline CAR_REGESTRATION_NUM & NUMBER & 22 & & & No \\ \hline C_TYPE & VARCHAR2 & 30 & & & Yes \\ \hline MODEL_YEAR & NUMBER & 22 & & & No \\ \hline BRAND_NAME & VARCHAR2 & 20 & & & No \\ \hline MILEAGE & NUMBER & 22 & & & No \\ \hline CAT_NUM & NUMBER & 22 & & & Yes \\ \hline \end{tabular}