Plain string

The Plain string channel is designed for scenarios where R code must be embedded in SQL. The default running mode is run; however, it can be overridden by setting the MODE environment variable. The code is passed as the value of the CODE_PLAIN environment variable. An additional environment variable, SHAPER_LIST, can be used to pass also the output signature.

The SQL query is presented in the example. Note that backslash signs denote a line continuation and should be omitted when pasting to nzsql:

SELECT * FROM TABLE WITH FINAL(nzr..r_udtf('CODE_PLAIN=\
"getNext();setOutput(0,''output value'');outputResult()"'))

The result matches previous examples from other sections:

COLUMNID | VALUE
----------+--------------
0 | output value
(1 row)

The following example specifies the output signature:

SELECT * FROM TABLE WITH FINAL(nzr..r_udtf('CODE_PLAIN=
"getNext();setOutput(0,''output value'');outputResult()",
SHAPER_LIST="value=list(NZ.VARIABLE,32)"'))

which results in the same output as previous examples:

value
--------------
output value
(1 row)

The SHAPER_LIST environment variable should contain the comma-separated entries in the form column name=data type. For character columns (variable and fixed), the data type must take the following form: list(NZ.DATATYPE,length). For other data types it is the data type identifier only.