4. The computer-implemented method of claim 3 , wherein the groups of query conditions are connected using a logical “AND” operator based on relationships between the plurality of underlying tables in the relational database, wherein the plurality of query conditions includes: (i) multiple query conditions pertaining to a first-name attribute and each specifying a different first name; (ii) multiple query conditions pertaining to a last-name attribute and each specifying a different last name; (iii) multiple query conditions pertaining to a zone improvement plan (ZIP)-code attribute and each specifying a different ZIP code; and (iv) multiple query conditions pertaining to a phone-area-code attribute and each specifying a different phone area code.
5. The computer-implemented method of claim 4 , wherein the first and second specified operators are distinct operators, wherein each of: (i) different query conditions within each group and (ii) different groups of query conditions are connected with a respective one of the first and second specified operators, even in absence of user input explicitly specifying any logical operator, wherein the proposed database query is modified by, in respective instances: (i) removing at least one condition from one of the groups of query conditions; (ii) moving at least one condition from a first one of the groups to a second one of the groups; (iii) changing one of the logical “OR” operators to a logical “AND” operator; and (iv) changing one of the logical “AND” operators to a logical “OR” operator.