Creating tables via dashboard in Supabase - Practice Exercises

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Table Creation Steps in Supabase Dashboard

Which of the following sequences correctly describes the steps to create a new table in the Supabase dashboard?

A Navigate to Database > Tables, click 'New Table', define columns, set primary key, then save.

B Go to Authentication > Users, click 'Add User', define user details, then save.

C Open Storage > Buckets, click 'New Bucket', set permissions, then save.

D Access SQL Editor, write CREATE TABLE statement, then run query.

💡 Hint

Focus on the dashboard section dedicated to tables and the typical steps to define a table.

Creating a table via the dashboard involves navigating to the Database section, selecting Tables, then using the 'New Table' button to define columns and keys before saving.

❓ dax_lod_result

intermediate

Result of a DAX Measure Using Table Created in Dashboard

Assume you created a table named Sales in Supabase dashboard with columns Product and Amount. You write this DAX measure in Power BI connected to Supabase:

 TotalSales = SUM(Sales[Amount]) 

What will TotalSales return if the table has rows: (Product: A, Amount: 100), (Product: B, Amount: 200)?

A Error: Table not found

B 100

C 200

D 300

💡 Hint

Think about what SUM does over the Amount column.

The SUM function adds all values in the Amount column. 100 + 200 = 300.

❓ visualization

advanced

Best Visualization for Newly Created Sales Table

You created a Sales table with columns Product and Amount. You want to show total sales per product in a dashboard. Which visualization type is best?

A Scatter plot of product vs amount

B Line chart showing sales over time

C Pie chart showing sales distribution by product

D Table showing raw data only

💡 Hint

Consider which chart best shows parts of a whole for categories.

A pie chart clearly shows how total sales are divided among products, making it easy to compare proportions.

❓ data_modeling

advanced

Modeling Relationships After Creating Tables

You created two tables via Supabase dashboard: Customers (CustomerID, Name) and Orders (OrderID, CustomerID, Amount). What is the best way to model their relationship in your BI tool?

A Create a one-to-many relationship from Customers.CustomerID to Orders.CustomerID

B Create a many-to-many relationship between Customers and Orders without keys

C Merge both tables into one flat table

D Do not create any relationship; use separate visuals

💡 Hint

Think about how orders relate to customers in real life.

Each customer can have many orders, so a one-to-many relationship from Customers to Orders on CustomerID is correct.

🔧 Debug

expert

Debugging Table Creation Error in Supabase Dashboard

You try to create a table named Sales with columns Product (text) and user (number). After saving, you get an error: 'Column name "user" conflicts with reserved keyword.' What should you do to fix this?

A Ignore the error and refresh the dashboard

B Rename the column from user to TotalAmount and save again

C Remove the Product column and save

D Change the data type of user to text and save

💡 Hint

Reserved keywords cannot be used as column names. Try renaming the column.

Renaming the column to a non-reserved name like TotalAmount avoids the conflict and allows saving.

Practice

1. What is the main purpose of creating tables via the Supabase dashboard?

easy

A. To deploy applications directly from the dashboard

B. To write complex SQL queries manually

C. To create user interface designs

D. To organize data with clear columns and constraints without coding

Solution

1. Step 1: Understand the dashboard's role

   The Supabase dashboard allows users to create tables visually without writing code.

2. Step 2: Identify the main benefit

   This method helps organize data clearly with columns and constraints easily set up.

3. Final Answer:

   To organize data with clear columns and constraints without coding -> Option D

4. Quick Check:

   Dashboard table creation = Organize data visually [OK]

Hint: Dashboard tables = visual data organization, no code needed [OK]

Common Mistakes:

• Confusing dashboard with SQL query writing
• Thinking dashboard creates app UI
• Assuming dashboard deploys apps

2. Which step is required to add a new column when creating a table in the Supabase dashboard?

easy

A. Run a database migration script

B. Write a SQL INSERT statement

C. Click 'Add Column' and define the column name and type

D. Upload a CSV file with column data

Solution

1. Step 1: Locate the column addition feature

   In the Supabase dashboard, you add columns by clicking the 'Add Column' button.

2. Step 2: Define column details

   After clicking, you specify the column name and data type to create it.

3. Final Answer:

   Click 'Add Column' and define the column name and type -> Option C

4. Quick Check:

   Add column = Click button + define name/type [OK]

Hint: Add columns by clicking 'Add Column' and setting details [OK]

Common Mistakes:

• Confusing column addition with data insertion
• Trying to upload data instead of defining structure
• Running scripts instead of using dashboard UI

3. After creating a table with columns id (integer, primary key) and name (text) via the Supabase dashboard, what will be the result of inserting {id: 1, name: 'Alice'} and then querying all rows?

medium

A. [{id: 1, name: 'Alice'}]

B. Error: Missing table schema

C. Empty result set

D. [{name: 'Alice'}]

Solution

1. Step 1: Understand table schema and insert

   The table has columns 'id' as primary key and 'name' as text. Inserting {id:1, name:'Alice'} matches schema.

2. Step 2: Query all rows after insert

   Querying all rows returns the inserted row as [{id: 1, name: 'Alice'}].

3. Final Answer:

   [{id: 1, name: 'Alice'}] -> Option A

4. Quick Check:

   Insert + query = inserted row returned [OK]

Hint: Insert matching schema, query returns inserted rows [OK]

Common Mistakes:

• Expecting error without schema mismatch
• Thinking query returns empty before insert
• Assuming partial row returned without id

4. You tried to create a table via the Supabase dashboard but received an error saying the column name is invalid. What is the most likely cause?

medium

A. Not selecting a data type for the column

B. Using spaces or special characters in the column name

C. Adding too many columns at once

D. Not clicking the 'Save' button after creation

Solution

1. Step 1: Identify invalid column name causes

   Column names cannot contain spaces or special characters in Supabase.

2. Step 2: Recognize common naming rules

   Valid names use letters, numbers, and underscores only.

3. Final Answer:

   Using spaces or special characters in the column name -> Option B

4. Quick Check:

   Invalid column name = spaces/special chars [OK]

Hint: Use only letters, numbers, underscores in column names [OK]

Common Mistakes:

• Ignoring naming rules and using spaces
• Forgetting to select data type (usually warned separately)
• Assuming too many columns cause naming errors

5. You want to create a table for customer orders with columns: order_id (primary key), customer_id, order_date, and total_amount. Which approach via the Supabase dashboard ensures data integrity and efficient queries?

hard

A. Set order_id as primary key, customer_id as foreign key, and choose appropriate data types

B. Create all columns as text type for flexibility

C. Skip primary key to allow duplicate orders

D. Add only order_id and total_amount columns

Solution

1. Step 1: Define primary key for uniqueness

   Setting order_id as primary key ensures each order is unique.

2. Step 2: Use foreign key and proper data types

   Defining customer_id as foreign key links orders to customers; choosing correct data types improves query efficiency.

3. Final Answer:

   Set order_id as primary key, customer_id as foreign key, and choose appropriate data types -> Option A

4. Quick Check:

   Primary + foreign keys + data types = data integrity [OK]

Hint: Use keys and correct types for integrity and speed [OK]

Common Mistakes:

• Using text for all columns losing type benefits
• Skipping primary key causing duplicates
• Ignoring foreign key relationships