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SQL for Branch Performance
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SQL for Branch Performance

HardSQL · PostgreSQL

Problem

Write a SQL query to analyze operational performance by branch, joining transaction, customer, and exception tables to identify the highest-volume branches with the lowest error rates. Use all available rows and count a transaction with one or more exceptions as one errored transaction.

Output

  1. One row per branch with branch_name, total_transactions, exception_transactions, error_rate, volume_rank, and error_rate_rank.
  2. Include all branches, ordering by volume rank, error rate ascending, and branch name ascending for ties.

Schema

transactions
ColumnTypeDescription
transaction_idPKINTUnique transaction identifier
customer_idINTCustomer associated with the transaction
branch_nameVARCHAR(100)Branch that processed the transaction
transaction_dateDATEDate the transaction was processed
customers
ColumnTypeDescription
customer_idPKINTUnique customer identifier
customer_nameVARCHAR(120)Customer full name
customer_segmentVARCHAR(40)Customer classification
exceptions
ColumnTypeDescription
exception_idPKINTUnique exception identifier
transaction_idINTTransaction associated with the exception
exception_typeVARCHAR(80)Operational exception category
resolved_atDATEDate the exception was resolved
Tablestransactionscustomersexceptions
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