Solution:Step 1: Understand CROSS JOIN outputEach row in A pairs with every row in B, so 2 rows in A x 2 rows in B = 4 rows total.Step 2: List all combinationsPairs are (Alice, X), (Alice, Y), (Bob, X), (Bob, Y) in that order.Final Answer:[('Alice', 'X'), ('Alice', 'Y'), ('Bob', 'X'), ('Bob', 'Y')]

[Solved] Given two tables:Table A:id | name1 | Alice2 | BobTable B:codeXYWhat is the result of:SELECT A.name, B.code FROM A CROSS JOIN B; | PostgreSQL

PostgreSQL - Joins in PostgreSQL

Given two tables:
Table A:
id | name
1 | Alice
2 | Bob

Table B:
code
X
Y

What is the result of:
SELECT A.name, B.code FROM A CROSS JOIN B;

A[('Alice', 'X'), ('Bob', 'Y')]

B[('Alice', 'X'), ('Alice', 'Y'), ('Bob', 'X'), ('Bob', 'Y')]

C[('Alice', 'X'), ('Bob', 'X'), ('Alice', 'Y'), ('Bob', 'Y')]

D[('Alice', 'X'), ('Bob', 'X')]

Step-by-Step Solution

Solution:

Step 1: Understand CROSS JOIN output
Each row in A pairs with every row in B, so 2 rows in A x 2 rows in B = 4 rows total.
Step 2: List all combinations
Pairs are (Alice, X), (Alice, Y), (Bob, X), (Bob, Y) in that order.
Final Answer:
[('Alice', 'X'), ('Alice', 'Y'), ('Bob', 'X'), ('Bob', 'Y')] -> Option B
Quick Check:
2 x 2 = 4 rows [OK]

Quick Trick: Multiply row counts of both tables for CROSS JOIN result size [OK]

Common Mistakes:

Assuming CROSS JOIN filters rows
Mixing order of pairs incorrectly
Counting only matching rows instead of all combinations

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Given two tables:

Step 1: Understand CROSS JOIN output

Step 2: List all combinations

Final Answer:

Quick Check:

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