SPI_fnumber
SPI_fnumber — determine the column number for the specified column name
Synopsis
int SPI_fnumber(TupleDescrowdesc, const char *colname)
Description
SPI_fnumber returns the column number for the column with the specified name. 
 If colname refers to a system column (e.g., oid) then the appropriate negative column number will be returned. The caller should be careful to test the return value for exact equality to SPI_ERROR_NOATTRIBUTE to detect an error; testing the result for less than or equal to 0 is not correct unless system columns should be rejected. 
Arguments
- TupleDesc- rowdesc
- input row description 
- const char *- colname
- column name 
Return Value
 Column number (count starts at 1), or SPI_ERROR_NOATTRIBUTE if the named column was not found.