试试这个查询:

SELECT
    CASE WHEN CHARINDEX('?uniquecode=', SourcePageURL) > 0
         THEN SUBSTRING(SourcePageURL,
                        1,
                        CHARINDEX('?uniquecode=', SourcePageURL) - 1)
         ELSE SourcePageURL END AS new_source
FROM sql_test;

如果您想使用此逻辑更新示例中的源网址，您可以尝试以下操作:

If you instead wanted to update the source URLs in your example using this logic, you could try the following:

UPDATE sql_test
SET SourcePageURL = SUBSTRING(SourcePageURL,
                        1,
                        CHARINDEX('?uniquecode=', SourcePageURL) - 1)
WHERE SourcePageURL LIKE '%?uniquecode=%';