Is there a risk of double-counting data when using the OR operator in the SQL query for multiple postal code ranges?

When using the OR operator in an SQL query for multiple postal code ranges, there is a risk of double-counting data if a record falls into more than one range. To solve this issue, you can use the BETWEEN operator instead of multiple OR conditions. This ensures that each record is only counted once based on its postal code falling within the specified range. 

// Define the postal code ranges
$postal_code_range_1 = '10000' and '19999';
$postal_code_range_2 = '20000' and '29999';

// SQL query using BETWEEN operator to avoid double-counting
$sql = "SELECT COUNT(*) FROM table_name WHERE postal_code BETWEEN $postal_code_range_1 AND $postal_code_range_2";

Keywords

PHP SQL OR operator data double-counting

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