v.what: new option to select columns (OSGeo#2458)

vector/v.what/main.c

@@ -37,7 +37,7 @@ int main(int argc, char **argv)
 	struct Flag *print, *topo, *shell, *json, *multiple;
     } flag;
     struct {
-	struct Option *map, *field, *coords, *maxdist, *type;
+	struct Option *map, *field, *coords, *maxdist, *type, *cols;
     } opt;
     struct Cell_head window;
     struct GModule *module;
@@ -49,6 +49,7 @@ int main(int argc, char **argv)
     char buf[2000];
     int i, level, ret, type;
     int *field;
+    char *columns;
     double xval, yval, xres, yres, maxd, x;
     double EW_DIST1, EW_DIST2, NS_DIST1, NS_DIST2;
     char nsres[30], ewres[30];
@@ -85,6 +86,10 @@ int main(int argc, char **argv)
     opt.maxdist->description = _("Query threshold distance");
     opt.maxdist->guisection = _("Threshold");
 
+    opt.cols = G_define_standard_option(G_OPT_DB_COLUMNS);
+    opt.cols->label = _("Name of attribute column(s)");
+    opt.cols->description = _("Default: all columns");
+
     flag.topo = G_define_flag();
     flag.topo->key = 'd';
     flag.topo->description = _("Print topological information (debugging)");
@@ -126,6 +131,27 @@ int main(int argc, char **argv)
     else
 	G_fatal_error(_("No input vector maps!"));
 
+    /* get specified column names */
+    if (opt.cols->answers && opt.cols->answers[0]) {
+	int col_alloc;
+	int new_len;
+
+	col_alloc = 1024;
+	columns = (char *)G_calloc(col_alloc, sizeof(char));
+	for (i = 0; opt.cols->answers[i]; i++) {
+	    new_len = strlen(columns) + strlen(opt.cols->answers[i]) + 1;
+	    if (new_len >= col_alloc) {
+		col_alloc = new_len + 1024;
+		columns = G_realloc(columns, col_alloc);
+	    }
+	    if (i > 0)
+		strcat(columns, ",");
+	    strcat(columns, opt.cols->answers[i]);
+	}
+    }
+    else
+	columns = "*";
+
     maxd = atof(opt.maxdist->answer);
     type = Vect_option_to_types(opt.type);
     output = flag.shell->answer ? OUTPUT_SCRIPT :
@@ -196,7 +222,7 @@ int main(int argc, char **argv)
 	    if (ret == 3 && (ch == ',' || ch == ' ' || ch == '\t')) {
 		what(Map, nvects, vect, xval, yval, maxd, type,
 		     flag.topo->answer, flag.print->answer, output,
-		     flag.multiple->answer, field);
+		     flag.multiple->answer, field, columns);
 	    }
 	    else {
 		G_warning(_("Unknown input format, skipping: '%s'"), buf);
@@ -210,7 +236,7 @@ int main(int argc, char **argv)
 	    xval = atof(opt.coords->answers[i]);
 	    yval = atof(opt.coords->answers[i + 1]);
 	    what(Map, nvects, vect, xval, yval, maxd, type, flag.topo->answer,
-		 flag.print->answer, output, flag.multiple->answer, field);
+		 flag.print->answer, output, flag.multiple->answer, field, columns);
 	}
     }
 

vector/v.what/what.c

@@ -17,7 +17,7 @@ static int nlines = 50;
 
 static void F_generate(const char *drvname, const char *dbname,
 		       const char *tblname, const char *key, int keyval,
-		       int output, char **form)
+		       int output, char **form, char *columns)
 {
     int col, ncols, sqltype, more;
     char buf[5000];
@@ -59,7 +59,7 @@ static void F_generate(const char *drvname, const char *dbname,
      * application before F_generate() is called, because it may be correct
      * (connection defined in DB but table does not exist) */
 
-    sprintf(buf, "select * from %s where %s = %d", tblname, key, keyval);
+    sprintf(buf, "select %s from %s where %s = %d", columns, tblname, key, keyval);
     G_debug(2, "%s", buf);
     db_set_string(&sql, buf);
     if (db_open_select_cursor(driver, &sql, &cursor, DB_SEQUENTIAL) != DB_OK)
@@ -145,7 +145,7 @@ void coord2bbox(double east, double north, double maxdist,
 }
 
 void write_cats(struct Map_info *Map, int field, struct line_cats *Cats,
-		int showextra, int output)
+		int showextra, int output, char *columns)
 {
     int i, j;
     char *formbuf1;
@@ -204,7 +204,7 @@ void write_cats(struct Map_info *Map, int field, struct line_cats *Cats,
 		    break;
 		}
 		F_generate(Fi->driver, Fi->database, Fi->table,
-			   Fi->key, Cats->cat[i], output, &form);
+			   Fi->key, Cats->cat[i], output, &form, columns);
 
 		switch (output) {
 		case OUTPUT_SCRIPT:
@@ -232,7 +232,7 @@ void write_cats(struct Map_info *Map, int field, struct line_cats *Cats,
 
 void what(struct Map_info *Map, int nvects, char **vect, double east,
 	  double north, double maxdist, int qtype, int topo, int showextra,
-	  int output, int multiple, int *field)
+	  int output, int multiple, int *field, char *columns)
 {
     struct line_pnts *Points;
     struct line_cats *Cats;
@@ -625,7 +625,7 @@ void what(struct Map_info *Map, int nvects, char **vect, double east,
 		}
 	    }			/* if height */
 
-	    write_cats(&Map[i], field[i], Cats, showextra, output);
+	    write_cats(&Map[i], field[i], Cats, showextra, output, columns);
 
 	    if (output == OUTPUT_JSON && multiple)
 		fprintf(stdout, "}");
@@ -770,7 +770,7 @@ void what(struct Map_info *Map, int nvects, char **vect, double east,
 	    if (centroid > 0)
 		Vect_read_line(&Map[i], Points, Cats, centroid);
 
-	    write_cats(&Map[i], field[i], Cats, showextra, output);
+	    write_cats(&Map[i], field[i], Cats, showextra, output, columns);
 
 	    if (output == OUTPUT_JSON && multiple)
 		fprintf(stdout, "}");

vector/v.what/what.h

@@ -7,6 +7,6 @@
 
 /* what.c */
 void what(struct Map_info *, int, char **,
-	  double, double, double, int, int, int, int, int, int *);
+	  double, double, double, int, int, int, int, int, int *, char *);
 
 #endif