SPI_getargcount
Name
SPI_getargcount -- return the number of arguments needed by a statement
  prepared by 
SPI_prepareSynopsis
int SPI_getargcount(SPIPlanPtr plan)
描述
   SPI_getargcount returns the number of arguments needed
   to execute a statement prepared by SPI_prepare.
  
参数
- SPIPlanPtr plan
-       prepared statement (returned by - SPI_prepare)
 
返回值
    The count of expected arguments for the plan.
    If the plan is NULL or invalid,
    SPI_result is set to SPI_ERROR_ARGUMENT
    and -1 is returned.