1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
|
/** @file sql-example.c
* @breif Example program showing SQL to perform query over objects.
* @author Copyright (c) 2003, 2004 Linas Vepstas <linas@linas.org>
*
* This example program shows how to configure an arbitrary
* programmer-defined oject "MyObj" so that the Query routines
* can be used on it. It consists of four basic peices:
* -- The object definition, showing how to hook into the query system.
* (this part is in the "my-object.c" file)
* -- Generic application intialization, including the creation of
* a number of instances of MyObj.
* -- QOF intialization, required before QOF can be used.
* -- The definition and running of a query, and a printout of the
* results.
*/
#include <glib.h>
#include <qof/qof.h>
#include "my-object.h"
/* ===================================================== */
QofBook *
my_app_init (void)
{
QofBook *book;
/* Perform the application object registeration */
myObjRegister ();
/* Create a new top-level object container */
book = qof_book_new();
return book;
}
void
my_app_shutdown (QofBook *book)
{
/* Terminate our storage. This prevents the system from
* being used any further. */
qof_book_destroy (book);
}
void
my_app_create_data (QofBook *book)
{
MyObj *m;
/* Pretend our app has some objects; we will perform
* the search over these objects */
m = my_obj_new (book);
m->a = 1;
m->b = 1;
m->memo = "Hiho Silver!";
m = my_obj_new (book);
m->a = 1;
m->b = 42;
m->memo = "The Answer to the Question";
m = my_obj_new (book);
m->a = 99;
m->b = 1;
m->memo = "M M M My Sharona";
}
/* ===================================================== */
/* A routine that will build an actual query, run it, and
* print the results.
*/
void
my_app_run_query (QofSqlQuery *q, char *sql_str)
{
GList *results, *n;
/* Run the query */
results = qof_sql_query_run (q, sql_str);
printf ("------------------------------------------\n");
printf ("Query string is: %s\n", sql_str);
printf ("Query returned %d results:\n", g_list_length(results));
for (n=results; n; n=n->next)
{
MyObj *m = n->data;
printf ("Found a matching object, a=%d b=%d memo=\"%s\"\n",
m->a, m->b, m->memo);
}
printf ("\n");
}
void
my_app_do_some_queries (QofBook *book)
{
QofSqlQuery *q;
GList *n;
/* Print out the baseline: all of the instances in the system */
printf ("\n");
printf ("My Object collection contains the following objects:\n");
QofCollection *coll = qof_book_get_collection (book, MYOBJ_ID);
GList *all_my_objs = qof_collection_get_data (coll);
for (n=all_my_objs; n; n=n->next)
{
MyObj *m = n->data;
printf (" a=%d b=%d memo=\"%s\"\n",
m->a, m->b, m->memo);
}
printf ("\n");
/* Create a new query */
q = qof_sql_query_new ();
/* Set the book to be searched */
qof_sql_query_set_book(q, book);
/* Describe the query to be performed.
* We want to find all objects whose "memo" field matches
* a particular string, or all objects whose "b" field is 42.
*/
char * str = "SELECT * FROM " MYOBJ_ID
" WHERE (" MYOBJ_MEMO " = 'M M M My Sharona') OR "
" (" MYOBJ_B " = 42);";
my_app_run_query (q, str);
/* Do some more */
my_app_run_query (q, "SELECT * FROM MyObj WHERE MyObj_a = 1;");
my_app_run_query (q, "SELECT * FROM MyObj WHERE (MyObj_a = 1) AND (MyObj_b=42);");
my_app_run_query (q, "SELECT * FROM MyObj WHERE (MyObj_a = 3);");
my_app_run_query (q, "SELECT * FROM MyObj;");
my_app_run_query (q, "SELECT * FROM MyObj ORDER BY MyObj_a DESC;");
my_app_run_query (q, "SELECT * FROM MyObj ORDER BY MyObj_b DESC;");
my_app_run_query (q, "SELECT * FROM MyObj WHERE MyObj_a = 1 ORDER BY MyObj_b DESC;");
/* The query isn't needed any more; discard it */
qof_sql_query_destroy (q);
}
/* ===================================================== */
int
main (int argc, char *argv[])
{
QofBook *book;
/* Initialize the QOF framework */
gnc_engine_get_string_cache();
guid_init();
qof_object_initialize ();
qof_query_init ();
qof_book_register ();
/* Do application-specific things */
book = my_app_init();
my_app_create_data(book);
my_app_do_some_queries (book);
my_app_shutdown (book);
/* Perform a clean shutdown */
qof_query_shutdown ();
qof_object_shutdown ();
guid_shutdown ();
gnc_engine_string_cache_destroy ();
}
/* =================== END OF FILE ===================== */
|
