How Can I Use SQL to Verify Exact Data Equivalence Between Two Tables?

Comparing Table Content for Exact Data Equivalence

When confronted with multiple tables containing identical column structures, it becomes imperative to validate their content similarity for data consistency purposes. This guide presents a comprehensive solution for comparing two tables, TableA and TableB, to determine if they contain precisely the same data values across all columns.

SQL Query for Exact Data Comparison

The following SQL query leverages the powerful "MINUS" or "EXCEPT" command to execute a comparative analysis between TableA and TableB:

select * from tableA
minus
select * from tableB

Logic of the Query

This query retrieves all rows from TableA and excludes any rows that match the corresponding rows in TableB. If no rows are returned, it indicates that both tables possess exactly the same data content for all columns.

Interpretation of Results

The absence of rows returned by the query confirms that TableA and TableB contain identical values in every column. Conversely, if any rows are returned, it indicates that the tables contain differing data and are not exact replicas. Implementing this method provides a reliable means of verifying data consistency and identifying potential discrepancies between tables.

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