kettle--组件（2）--计算器

组件如下：

对计算类型的说明如下：

The table below contains descriptions associated with the calculator step:

Function	Description	Required fields
Set field to constant A	Create a field with a constant value.	A
Create a copy of field A	Create a copy of a field with the given field value.	A
A + B	A plus B.	A and B
A - B	A minus B.	A and B
A * B	A multiplied by B.	A and B
A / B	A divided by B.	A and B
A * A	The square of A.	A
SQRT( A )	The square root of A.	A
100 * A / B	Percentage of A in B.	A and B
A - ( A * B / 100 )	Subtract B% of A.	A and B
A + ( A * B / 100 )	Add B% to A.	A and B
A + B *C	Add A and B times C.	A, B and C
SQRT( A*A + B*B )	Calculate ?(A2+B2).	A and B
ROUND( A )	Returns the closest Integer to the argument. The result is rounded to an Integer by adding 1/2, taking the floor of the result, and casting the result to type int. In other words, the result is equal to the value of the expression: floor (a + 0.5). In case you need the rounding method "Round half to even", use the following method ROUND( A, B ) with no decimals (B=0).	A
ROUND( A, B )	Round A to the nearest even number with B decimals. The used rounding method is "Round half to even", it is also called unbiased rounding, convergent rounding, statistician's rounding, Dutch rounding, Gaussian rounding, odd-even rounding, bankers' rounding or broken rounding, and is widely used in bookkeeping. This is the default rounding mode used in IEEE 754 computing functions and operators. In Germany it is often called "Mathematisches Runden".	A and B
STDROUND( A )	Round A to the nearest integer. The used rounding method is "Round half away from zero", it is also called standard or common rounding. In Germany it is known as "kaufmännische Rundung" (and defined in DIN 1333).	A
STDROUND( A, B )	Same rounding method used as in STDROUND (A) but with B decimals.	A and B
CEIL( A )	The ceiling function map a number to the smallest following integer.	A
FLOOR( A )	The floor function map a number to the largest previous integer.	A
NVL( A, B )	If A is not NULL, return A, else B. Note that sometimes your variable won't be null but an empty string.	A and B
Date A + B days	Add B days to Date field A.	A and B
Year of date A	Calculate the year of date A.	A
Month of date A	Calculate number the month of date A.	A
Day of year of date	A Calculate the day of year (1-365).	A
Day of month of date A	Calculate the day of month (1-31).	A
Day of week of date A	Calculate the day of week (1-7).	A
Week of year of date A	Calculate the week of year (1-54).	A
ISO8601 Week of year of date A	Calculate the week of the year ISO8601 style (1-53).	A
ISO8601 Year of date A	Calculate the year ISO8601 style.	A
Byte to hex encode of string A	Encode bytes in a string to a hexadecimal representation.	A
Hex encode of string A	Encode a string in its own hexadecimal representation.	A
Char to hex encode of string A	Encode characters in a string to a hexadecimal representation.	A
Hex decode of string A	Decode a string from its hexadecimal representation (add a leading 0 when A is of odd length).	A
Checksum of a file A using CRC-32	Calculate the checksum of a file using CRC-32.	A
Checksum of a file A using Adler-32	Calculate the checksum of a file using Adler-32.	A
Checksum of a file A using MD5	Calculate the checksum of a file using MD5.	A
Checksum of a file A using SHA-1	Calculate the checksum of a file using SHA-1.	A
Levenshtein Distance (Source A and Target B)	Calculates the Levenshtein Distance: http://en.wikipedia.org/wiki/Levenshtein_distance	A and B
Metaphone of A (Phonetics)	Calculates the metaphone of A:  http://en.wikipedia.org/wiki/Metaphone	A
Double metaphone of A	Calculates the double metaphone of A: http://en.wikipedia.org/wiki/Double_Metaphone	A
Absolute value ABS(A)	Calculates the Absolute value of A.	A
Remove time from a date A	Removes time value of A.	A
Date A - Date B (in days)	Calculates difference, in days, between A date field and B date field.	A and B
A + B + C	A plus B plus C.	A, B, and C
First letter of each word of a string A in capital	Transforms the first letter of each word within a string.	A
UpperCase of a string A	Transforms a string to uppercase.	A
LowerCase of a string A	Transforms a string to lowercase.	A
Mask XML content from string A	Escape XML content; replace characters with &values.	A
Protect (CDATA) XML content from string A	Indicates an XML string is general character data, rather than non-character data or character data with a more specific, limited structure. The given string will be enclosed into <![CDATA[String]]>.	A
Remove CR from a string A	Removes carriage returns from a string.	A
Remove LF from a string A	Removes linefeeds from a string.	A
Remove CRLF from a string A	Removes carriage returns/linefeeds from a string.	A
Remove TAB from a string A	Removes tab characters from a string.	A
Return only digits from string A	Outputs only Outputs only digits (0-9) from a string from a string.	A
Remove digits from string A	Removes all digits (0-9) from a string.	A
Return the length of a string A	Returns the length of the string.	A
Load file content in binary	Loads the content of the given file (in field A) to a binary data type (e.g. pictures).	A
Add time B to date A	Add the time to a date, returns date and time as one value.	A and B
Quarter of date A	Returns the quarter (1 to 4) of the date.	A
variable substitution in string A	Substitute variables within a string.	A
Unescape XML content	Unescape XML content from the string.	A
Escape HTML content	Escape HTML within the string.	A
Unescape HTML content	Unescape HTML within the string.	A
Escape SQL content	Escapes the characters in a String to be suitable to pass to an SQL query.	A
Date A - Date B (working days)	Calculates the difference between Date field A and Date field B (only working days Mon-Fri).	A and B
Date A + B Months	Add B months to Date field A.	A
Check if an XML file A is well formed	Validates XML file input.	A
Check if an XML string A is well formed	Validates XML string input.	A
Get encoding of file A	Guess the best encoding (UTF-8) for the given file.	A
Dameraulevenshtein distance between String A and String B	Calculates Dameraulevenshtein distance between strings: http://en.wikipedia.org/wiki/Damerau%E2%80%93Levenshtein_distance	A and B
NeedlemanWunsch distance between String A and String B	Calculates NeedlemanWunsch distance between strings: http://en.wikipedia.org/wiki/Needleman%E2%80%93Wunsch_algorithm	A and B
Jaro similitude between String A and String B	Returns the Jaro similarity coefficient between two strings.	A and B
JaroWinkler similitude between String A and String B	Returns the Jaro similarity coefficient between two string: http://en.wikipedia.org/wiki/Jaro%E2%80%93Winkler_distance	A and B
SoundEx of String A	Encodes a string into a Soundex value.	A
RefinedSoundEx of String A	Retrieves the Refined Soundex code for a given string object	A
Date A + B Hours	Add B hours to Date field A	A and B
Date A + B Minutes	Add B minutes to Date field A	A and B
Date A - Date B (milliseconds)	Subtract B milliseconds from Date field A	A and B
Date A - Date B (seconds)	Subtract B seconds from Date field A	A and B
Date A - Date B (minutes)	Subtract B minutes from Date field A	A and B
Date A - Date B (hours)	Subtract B hours from Date field A	A and B
Hour of Day of Date A	Extract the hour part of the given date	A
Minute of Hour of Date A	Extract the minute part of the given date	A
Second of Hour of Date A	Extract the second part of a given date	A

 

 

个人理解：

自己再处理单列加常量数值的使用用到这里，可以组件里定义一个常量数值，然后第二行引用，做进一步运算。