sqlserver求小数取位

SELECT BALANCE_AMT_TC
FROM PAYABLE_OBJECT
WHERE SUBSTRING(CAST(CONVERT(DECIMAL(18, 5), ROUND(BALANCE_AMT_TC, 5)) AS VARCHAR(50)),
CHARINDEX('.',
REVERSE(CAST(CONVERT(DECIMAL(18, 5), ROUND(BALANCE_AMT_TC,
5)) AS VARCHAR(50))))
+ 5, 3) <> ''
AND CAST(SUBSTRING(CAST(CONVERT(DECIMAL(18, 5), ROUND(BALANCE_AMT_TC,
5)) AS VARCHAR(50)),
CHARINDEX('.',
REVERSE(CAST(CONVERT(DECIMAL(18, 5), ROUND(BALANCE_AMT_TC,
5)) AS VARCHAR(50))))
+ 5, 3) AS DECIMAL(18, 6)) > 0;