Find Mismatches Between Tables | Dataford Interview Questions

How would you write a SQL query using joins to compare records between two tables and find mismatches?

Use the provided employee record tables. Return records that are missing from either table or have different values in any compared attribute.

Output

One row per mismatched employee record
Include employee_id, source and target values for name, status, hourly rate, and department, plus mismatch_type
Sort by employee_id ascending

source_employee_records

Column	Type	Description
employee_idPK	INT	Employee identifier in the source table
employee_name	VARCHAR(100)	Employee name
employment_status	VARCHAR(20)	Current employment status
hourly_rate	NUMERIC(10,2)	Hourly pay rate
department	VARCHAR(50)	Employee department

target_employee_records

Column	Type	Description
employee_idPK	INT	Employee identifier in the target table
employee_name	VARCHAR(100)	Employee name
employment_status	VARCHAR(20)	Current employment status
hourly_rate	NUMERIC(10,2)	Hourly pay rate
department	VARCHAR(50)	Employee department

Your question is Find Mismatches Between Tables. Start with the requirements and the two tables in the Question tab.

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