SELECT CASE WHEN THEN ELSE END AS

方法一：
SELECT CASE WHEN SUBSTRING(timerange, LENGTH(timerange)) < "5"
THEN CONCAT(SUBSTRING(timerange, 1, LENGTH(timerange) - 1), "0")
ELSE CONCAT(SUBSTRING(timerange, 1, LENGTH(timerange) - 1), "5")
END AS timerange
FROM Employee;
方法二：

import org.apache.hadoop.hive.ql.exec.UDFArgumentException;
import org.apache.hadoop.hive.ql.exec.UDFArgumentLengthException;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.ql.udf.generic.GenericUDF;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorUtils;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.IntObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory;
import org.apache.hadoop.hive.serde2.objectinspector.primitive.StringObjectInspector;

public class TimeRangeConverter GenericUDF {

@Override
public ObjectInspector initialize(ObjectInspector[] arguments) throws UDFArgumentException {
if (arguments.length != 1) {
throw new UDFArgumentLengthException("The function time_range_converter(time_rage) requires 1 argument.");
}

ObjectInspector timeRangeVal = arguments[0];

if (!(timeRangeVal instanceof StringObjectInspector)) {
throw new UDFArgumentException("First argument must be of type String (time_range as String)");
}
return PrimitiveObjectInspectorFactory.writableStringObjectInspector;
}

@Override
public Object evaluate(DeferredObject[] arguments) throws HiveException {
String timeRangeVal = (String) ObjectInspectorUtils.copyToStandardJavaObject(arguments[0].get(),
PrimitiveObjectInspectorFactory.javaStringObjectInspector);

char[] characters = timeRangeVal.toCharArray();

if (characters[characters.length - 1] > '5') {
characters[characters.length - 1] = '5';
} else {
characters[characters.length - 1] = '0';
}

return String.valueOf(characters);
}

@Override
public String getDisplayString(String[] arguments) {
assert (arguments.length == 1);
return "time_range_converter(" + arguments[0] + ")";
}
}
Call the Hive update statement like:
CREATE TEMPORARY FUNCTION time_range_converterAS 'TimeRangeConverter';

UPDATE
Employee
SET
timerange = time_range_converter(timerange);