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Diffstat (limited to 'src/third_party/wiredtiger/examples/c/ex_call_center.c')
| -rw-r--r-- | src/third_party/wiredtiger/examples/c/ex_call_center.c | 249 |
1 files changed, 249 insertions, 0 deletions
diff --git a/src/third_party/wiredtiger/examples/c/ex_call_center.c b/src/third_party/wiredtiger/examples/c/ex_call_center.c new file mode 100644 index 00000000000..d401507d165 --- /dev/null +++ b/src/third_party/wiredtiger/examples/c/ex_call_center.c @@ -0,0 +1,249 @@ +/*- + * Public Domain 2014-2016 MongoDB, Inc. + * Public Domain 2008-2014 WiredTiger, Inc. + * + * This is free and unencumbered software released into the public domain. + * + * Anyone is free to copy, modify, publish, use, compile, sell, or + * distribute this software, either in source code form or as a compiled + * binary, for any purpose, commercial or non-commercial, and by any + * means. + * + * In jurisdictions that recognize copyright laws, the author or authors + * of this software dedicate any and all copyright interest in the + * software to the public domain. We make this dedication for the benefit + * of the public at large and to the detriment of our heirs and + * successors. We intend this dedication to be an overt act of + * relinquishment in perpetuity of all present and future rights to this + * software under copyright law. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. + * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR + * OTHER DEALINGS IN THE SOFTWARE. + * + * ex_call_center.c + * This is an example application that demonstrates how to map a + * moderately complex SQL application into WiredTiger. + */ + +#include <inttypes.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include <wiredtiger.h> + +static const char *home; + +/*! [call-center decl] */ +/* + * In SQL, the tables are described as follows: + * + * CREATE TABLE Customers(id INTEGER PRIMARY KEY, + * name VARCHAR(30), address VARCHAR(50), phone VARCHAR(15)) + * CREATE INDEX CustomersPhone ON Customers(phone) + * + * CREATE TABLE Calls(id INTEGER PRIMARY KEY, call_date DATE, + * cust_id INTEGER, emp_id INTEGER, call_type VARCHAR(12), + * notes VARCHAR(25)) + * CREATE INDEX CallsCustDate ON Calls(cust_id, call_date) + * + * In this example, both tables will use record numbers for their IDs, which + * will be the key. The C structs for the records are as follows. + */ + +/* Customer records. */ +typedef struct { + uint64_t id; + const char *name; + const char *address; + const char *phone; +} CUSTOMER; + +/* Call records. */ +typedef struct { + uint64_t id; + uint64_t call_date; + uint64_t cust_id; + uint64_t emp_id; + const char *call_type; + const char *notes; +} CALL; +/*! [call-center decl] */ + +int +main(void) +{ + int count, exact, ret; + WT_CONNECTION *conn; + WT_SESSION *session; + WT_CURSOR *cursor; + CUSTOMER cust, *custp, cust_sample[] = { + { 0, "Professor Oak", "LeafGreen Avenue", "123-456-7890" }, + { 0, "Lorelei", "Sevii Islands", "098-765-4321" }, + { 0, NULL, NULL, NULL } + }; + CALL call, *callp, call_sample[] = { + { 0, 32, 1, 2, "billing", "unavailable" }, + { 0, 33, 1, 2, "billing", "available" }, + { 0, 34, 1, 2, "reminder", "unavailable" }, + { 0, 35, 1, 2, "reminder", "available" }, + { 0, 0, 0, 0, NULL, NULL } + }; + + /* + * Create a clean test directory for this run of the test program if the + * environment variable isn't already set (as is done by make check). + */ + if (getenv("WIREDTIGER_HOME") == NULL) { + home = "WT_HOME"; + ret = system("rm -rf WT_HOME && mkdir WT_HOME"); + } else + home = NULL; + + if ((ret = wiredtiger_open(home, NULL, "create", &conn)) != 0) { + fprintf(stderr, "Error connecting to %s: %s\n", + home, wiredtiger_strerror(ret)); + return (1); + } + /* Note: further error checking omitted for clarity. */ + + /*! [call-center work] */ + ret = conn->open_session(conn, NULL, NULL, &session); + + /* + * Create the customers table, give names and types to the columns. + * The columns will be stored in two groups: "main" and "address", + * created below. + */ + ret = session->create(session, "table:customers", + "key_format=r," + "value_format=SSS," + "columns=(id,name,address,phone)," + "colgroups=(main,address)"); + + /* Create the main column group with value columns except address. */ + ret = session->create(session, + "colgroup:customers:main", "columns=(name,phone)"); + + /* Create the address column group with just the address. */ + ret = session->create(session, + "colgroup:customers:address", "columns=(address)"); + + /* Create an index on the customer table by phone number. */ + ret = session->create(session, + "index:customers:phone", "columns=(phone)"); + + /* Populate the customers table with some data. */ + ret = session->open_cursor( + session, "table:customers", NULL, "append", &cursor); + for (custp = cust_sample; custp->name != NULL; custp++) { + cursor->set_value(cursor, + custp->name, custp->address, custp->phone); + ret = cursor->insert(cursor); + } + ret = cursor->close(cursor); + + /* + * Create the calls table, give names and types to the columns. All the + * columns will be stored together, so no column groups are declared. + */ + ret = session->create(session, "table:calls", + "key_format=r," + "value_format=qrrSS," + "columns=(id,call_date,cust_id,emp_id,call_type,notes)"); + + /* + * Create an index on the calls table with a composite key of cust_id + * and call_date. + */ + ret = session->create(session, "index:calls:cust_date", + "columns=(cust_id,call_date)"); + + /* Populate the calls table with some data. */ + ret = session->open_cursor( + session, "table:calls", NULL, "append", &cursor); + for (callp = call_sample; callp->call_type != NULL; callp++) { + cursor->set_value(cursor, callp->call_date, callp->cust_id, + callp->emp_id, callp->call_type, callp->notes); + ret = cursor->insert(cursor); + } + ret = cursor->close(cursor); + + /* + * First query: a call arrives. In SQL: + * + * SELECT id, name FROM Customers WHERE phone=? + * + * Use the cust_phone index, lookup by phone number to fill the + * customer record. The cursor will have a key format of "S" for a + * string because the cust_phone index has a single column ("phone"), + * which is of type "S". + * + * Specify the columns we want: the customer ID and the name. This + * means the cursor's value format will be "rS". + */ + ret = session->open_cursor(session, + "index:customers:phone(id,name)", NULL, NULL, &cursor); + cursor->set_key(cursor, "123-456-7890"); + ret = cursor->search(cursor); + if (ret == 0) { + ret = cursor->get_value(cursor, &cust.id, &cust.name); + printf("Read customer record for %s (ID %" PRIu64 ")\n", + cust.name, cust.id); + } + ret = cursor->close(cursor); + + /* + * Next query: get the recent order history. In SQL: + * + * SELECT * FROM Calls WHERE cust_id=? ORDER BY call_date DESC LIMIT 3 + * + * Use the call_cust_date index to find the matching calls. Since it is + * is in increasing order by date for a given customer, we want to start + * with the last record for the customer and work backwards. + * + * Specify a subset of columns to be returned. (Note that if these were + * all covered by the index, the primary would not have to be accessed.) + * Stop after getting 3 records. + */ + ret = session->open_cursor(session, + "index:calls:cust_date(cust_id,call_type,notes)", + NULL, NULL, &cursor); + + /* + * The keys in the index are (cust_id,call_date) -- we want the largest + * call date for a given cust_id. Search for (cust_id+1,0), then work + * backwards. + */ + cust.id = 1; + cursor->set_key(cursor, cust.id + 1, 0); + ret = cursor->search_near(cursor, &exact); + + /* + * If the table is empty, search_near will return WT_NOTFOUND, else the + * cursor will be positioned on a matching key if one exists, or an + * adjacent key if one does not. If the positioned key is equal to or + * larger than the search key, go back one. + */ + if (ret == 0 && exact >= 0) + ret = cursor->prev(cursor); + for (count = 0; ret == 0 && count < 3; ++count) { + ret = cursor->get_value(cursor, + &call.cust_id, &call.call_type, &call.notes); + if (call.cust_id != cust.id) + break; + printf("Call record: customer %" PRIu64 " (%s: %s)\n", + call.cust_id, call.call_type, call.notes); + ret = cursor->prev(cursor); + } + /*! [call-center work] */ + + ret = conn->close(conn, NULL); + + return (ret); +} |