Geografic-Information-System/db/drivers/postgres/fetch.c

/* TODO: implement time zone handling */

#include <stdlib.h>
#include <string.h>
#include <grass/dbmi.h>
#include "globals.h"
#include "proto.h" 
#include <grass/glocale.h>

int
db__driver_fetch (dbCursor *cn, int position, int *more)

{
    cursor     *c;
    dbToken    token;    
    dbTable    *table;
    int        i;

    /* get cursor token */
    token = db_get_cursor_token(cn);

    /* get the cursor by its token */
    if (!(c = (cursor *) db_find_token(token))) {
	append_error ("Cursor not found");
	report_error();
	return DB_FAILED;
    }

    /* fetch on position */
    switch (position)
    { 
    case DB_NEXT:
	c->row++;
	break;
    case DB_CURRENT:
	break;
    case DB_PREVIOUS:
	c->row--;
    	break;
    case DB_FIRST:
	c->row = 0;
	break;
    case DB_LAST:
	c->row = c->nrows - 1;
	break;
    };

    G_debug ( 3, "row = %d nrows = %d", c->row, c->nrows );
    if ( c->row < 0 || c->row >= c->nrows ) {
	*more = 0;
	return DB_OK;
    }

    *more = 1;

    /* get the data out of the descriptor into the table */
    table = db_get_cursor_table(cn);

    for (i = 0; i < c->ncols; i++) {
	int col, gpgtype, sqltype;
	dbColumn   *column;
	dbValue    *value;

	col = c->cols[i]; /* known cols */
 		
	column = db_get_table_column (table, i);
	gpgtype  = db_get_column_host_type(column);
	sqltype = db_get_column_sqltype(column);

	value  = db_get_column_value (column);
	db_zero_string (&value->s);
	
	/* Is null? */
	if ( PQgetisnull(c->res, c->row, col ) ) {
	    value->isNull = 1;
	    continue;
	} else {
	    value->isNull = 0;
	}

	G_debug (3, "row %d, col %d, gpgtype %d, sqltype %d: val = '%s'", 
		    c->row, col, gpgtype, sqltype, PQgetvalue(c->res, c->row, col) );
	
	switch (gpgtype) {
	    int ns, tz;
	    
	    case PG_TYPE_CHAR:
	    case PG_TYPE_BPCHAR:
	    case PG_TYPE_VARCHAR:
	    case PG_TYPE_TEXT:
		db_set_string ( &(value->s),  PQgetvalue(c->res, c->row, col) );
		break;

	    case PG_TYPE_BIT:
	    case PG_TYPE_INT2:
	    case PG_TYPE_INT4:
	    case PG_TYPE_INT8:
	    case PG_TYPE_SERIAL:
	    case PG_TYPE_OID:
	    	value->i = atoi ( PQgetvalue(c->res, c->row, col) );
		break;
		
	    case PG_TYPE_FLOAT4:
	    case PG_TYPE_FLOAT8:
	    case PG_TYPE_NUMERIC:
	    	value->d = atof ( PQgetvalue(c->res, c->row, col) );
		break;
		
 	    /* Note: we have set DATESTYLE TO ISO in db_driver_open_select_cursor() so datetime
	     *       format should be ISO */

	    case PG_TYPE_DATE:
		/* Example: '1999-01-25' */
		ns = sscanf( PQgetvalue(c->res, c->row, col), "%4d-%2d-%2d",
			     &(value->t.year), &(value->t.month), &(value->t.day) ); 

		if ( ns != 3 ) {
		    append_error ( "Cannot scan date:");
		    append_error ( PQgetvalue(c->res, c->row, col) );
		    report_error();
		    return DB_FAILED;
		}
		value->t.hour = 0;
		value->t.minute = 0;
		value->t.seconds = 0.0;
		break;

	    case PG_TYPE_TIME:
		/* Example: '04:05:06.25', '04:05:06' */
		ns = sscanf( PQgetvalue(c->res, c->row, col), "%2d:%2d:%lf",
			     &(value->t.hour), &(value->t.minute), &(value->t.seconds) );

		if ( ns != 3 ) {
		    append_error ( "Cannot scan time:");
		    append_error ( PQgetvalue(c->res, c->row, col) );
		    report_error();
		    return DB_FAILED;
		}
		value->t.year = 0;
		value->t.month = 0;
		value->t.day = 0;
		break;

	    case PG_TYPE_TIMESTAMP:
		/* Example: '1999-01-25 04:05:06.25+01', '1999-01-25 04:05:06' */
		ns = sscanf( PQgetvalue(c->res, c->row, col), "%4d-%2d-%2d %2d:%2d:%lf%3d",
			     &(value->t.year), &(value->t.month), &(value->t.day), 
			     &(value->t.hour), &(value->t.minute), &(value->t.seconds), &tz );

		if ( ns == 7 ) {
		    append_error ( "Cannot scan timestamp (no idea how to process time zone):");
		    append_error ( PQgetvalue(c->res, c->row, col) );
		    report_error();
		    return DB_FAILED;
		} else if ( ns < 6 ) {
		    append_error ( "Cannot scan timestamp (not enough arguments):");
		    append_error ( PQgetvalue(c->res, c->row, col) );
		    report_error();
		    return DB_FAILED;
		}
		break;

	    case PG_TYPE_BOOL:
		if ( strcmp ( PQgetvalue(c->res, c->row, col), "t") == 0 )
		    db_set_string ( &(value->s), "1");
		else if ( strcmp ( PQgetvalue(c->res, c->row, col), "f") == 0 )
		    db_set_string ( &(value->s), "0" );
		else
		    G_warning (_("Cannot recognize boolean value"));
		break;
	}
    }
    G_debug (3, "Row fetched" );
    return DB_OK;
}

int
db__driver_get_num_rows  (dbCursor *cn)

{
    cursor     *c;
    dbToken    token;

    /* get cursor token */
    token = db_get_cursor_token(cn);

    /* get the cursor by its token */
    if (!(c = (cursor *) db_find_token(token))) {
       append_error("Cursor not found");
       report_error();
       return DB_FAILED;
    }

    return ( c->nrows );
}