func()

in internal/database/postgres/postgres.go [181:225]

• 36 lines of code
• 6 McCabe index (conditional complexity)

func (h postgresHandler) GetColumnMetadata(db *database.DB, tableName string, columnName string) (map[string]interface{}, error) {
	// Quote table and column names to handle special characters and spaces
	quotedTable := h.QuoteIdentifier(tableName) // Use handler's QuoteIdentifier
	quotedColumn := h.QuoteIdentifier(columnName)

	// Get distinct count
	distinctQuery := fmt.Sprintf("SELECT COUNT(DISTINCT %s::text) FROM %s", quotedColumn, quotedTable)
	var distinctCount int
	err := db.QueryRow(distinctQuery).Scan(&distinctCount)
	if err != nil {
		return nil, fmt.Errorf("failed to get distinct count: %w", err)
	}

	// Get null count
	nullQuery := fmt.Sprintf("SELECT COUNT(*) FROM %s WHERE %s IS NULL", quotedTable, quotedColumn)
	var nullCount int
	err = db.QueryRow(nullQuery).Scan(&nullCount)
	if err != nil {
		return nil, fmt.Errorf("failed to get null count: %w", err)
	}

	// Get example values (top 3)
	exampleQuery := fmt.Sprintf("SELECT DISTINCT %s::text FROM %s WHERE %s IS NOT NULL LIMIT 3",
		quotedColumn, quotedTable, quotedColumn)
	rows, err := db.Query(exampleQuery)
	if err != nil {
		return nil, fmt.Errorf("failed to get example values: %w", err)
	}
	defer rows.Close()

	var examples []string
	for rows.Next() {
		var value string
		if err := rows.Scan(&value); err != nil {
			return nil, fmt.Errorf("error scanning example value: %w", err)
		}
		examples = append(examples, value)
	}

	return map[string]interface{}{
		"DistinctCount": distinctCount,
		"NullCount":     nullCount,
		"ExampleValues": examples,
	}, nil
}