org.apache.pig.builtin
Class UPPER

java.lang.Object
  extended by org.apache.pig.EvalFunc<String>
      extended by org.apache.pig.builtin.UPPER

public class UPPER
extends EvalFunc<String>

UPPER implements eval function to convert a string to upper case Example: A = load 'mydata' as (name); B = foreach A generate UPPER(name);


Field Summary
 
Fields inherited from class org.apache.pig.EvalFunc
log, pigLogger, reporter, returnType
 
Constructor Summary
UPPER()
           
 
Method Summary
 String exec(Tuple input)
          Upper-cases an input string.
 List<FuncSpec> getArgToFuncMapping()
          Allow a UDF to specify type specific implementations of itself.
 Schema outputSchema(Schema input)
          This method gives a name to the column.
 
Methods inherited from class org.apache.pig.EvalFunc
finish, getCacheFiles, getLogger, getPigLogger, getReporter, getReturnType, getSchemaName, isAsynchronous, progress, setPigLogger, setReporter, warn
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

UPPER

public UPPER()
Method Detail

exec

public String exec(Tuple input)
            throws IOException
Upper-cases an input string.

Specified by:
exec in class EvalFunc<String>
Parameters:
input - tuple; first column is assumed to have the column to convert
Returns:
result, of type T.
Throws:
IOException

outputSchema

public Schema outputSchema(Schema input)
This method gives a name to the column.

Overrides:
outputSchema in class EvalFunc<String>
Parameters:
input - - schema of the input data
Returns:
schema of the input data

getArgToFuncMapping

public List<FuncSpec> getArgToFuncMapping()
                                   throws FrontendException
Description copied from class: EvalFunc
Allow a UDF to specify type specific implementations of itself. For example, an implementation of arithmetic sum might have int and float implementations, since integer arithmetic performs much better than floating point arithmetic. Pig's typechecker will call this method and using the returned list plus the schema of the function's input data, decide which implementation of the UDF to use.

Overrides:
getArgToFuncMapping in class EvalFunc<String>
Returns:
A List containing FuncSpec objects representing the EvalFunc class which can handle the inputs corresponding to the schema in the objects. Each FuncSpec should be constructed with a schema that describes the input for that implementation. For example, the sum function above would return two elements in its list:
  1. FuncSpec(this.getClass().getName(), new Schema(new Schema.FieldSchema(null, DataType.DOUBLE)))
  2. FuncSpec(IntSum.getClass().getName(), new Schema(new Schema.FieldSchema(null, DataType.INTEGER)))
This would indicate that the main implementation is used for doubles, and the special implementation IntSum is used for ints.
Throws:
FrontendException


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