Remove Redundant Parentheses | Dataford Interview Questions

Explain how you would remove redundant parentheses from an expression.

The expressions are stored as text. For this task, parentheses are redundant only when they directly enclose a single identifier or integer operand. Preserve parentheses around compound expressions and exclude inactive or null expressions.

Output

One row per eligible expression, with expression_group, expression_id, and cleaned_expression
Sort by expression_group ascending, then expression_id ascending

Schema

expression_groups

Column	Type	Description
group_idPK	INT	Unique group identifier
expression_group	VARCHAR(50)	Display name for the expression group

expressions

Column	Type	Description
expression_idPK	INT	Unique expression identifier
group_id	INT	Associated expression group
expression_text	TEXT	Expression stored as text
is_active	BOOLEAN	Whether the expression should be processed

Your question is Remove Redundant Parentheses. Start with the requirements and the two tables in the Question tab.

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