char *orgName[] = {
"yun j ji yunji yunj yji yj z zh zha zhao q qi qia qian d du dua duan zhaoqian zhaoq
zhqian zhq zqian zq qianduan qiand qduan qd zhaoqianduan zhaoqiand zhaoqduan zhaoqd
zhqianduan zhqiand zhqduan zhqd zqianduan zqiand zqduan zqd",
"murren m mu l lu lun mulun mul mlun ml",
"l lu m ma man luman lum lman lm",
"d di din ding d di din ding f fu w wu dingding dingd
dding dd dingfu dingf dfu df fuwu fuw fwu fw dingdingfu dingdingf
dingdfu dingdf ddingfu ddingf ddfu ddf dingfuwu dingfuw dingfwu dingfw
dfuwu dfuw dfwu dfw dingdingfuwu dingdingfuw dingdingfwu dingdingfw
dingdfuwu dingdfuw dingdfwu dingdfw ddingfuwu ddingfuw ddingfwu ddingfw
ddfuwu ddfuw ddfwu ddfw l li x xi xia lixia lix lxia lx",
"lucy y ya yan x xi yanxi yanx yxi yx",
"p pe pen peng l le lei penglei pengl plei pl lucy"
};
char *nickName[] = {
"ab",
"bc",
"cd",
"de",
"ef",
"fg"
};
int id[] = { 21078,21218,21125,53234,40824,164873 };
void prepareSchema_prefix(sqlite3 *db) {
char *schemas[] = {
"PRAGMA journal_mode=WAL;",
"drop table if exists tbl;",
"drop table if exists tbl_fts;",
"create table if not exists tbl(name text, uid int primary key, nick text);",
"create virtual table if not exists tbl_fts USING fts5(name, uid);",
"create trigger if not exists trigger_insert_tbl after insert on tbl \
begin \
replace into tbl_fts(rowid, name, uid)
values(new.rowid<http://new.rowid>,new.name<http://new.name>,new.uid<http://new.uid>);
\
end;",
"create trigger if not exists trigger_update_tbl after update on tbl \
begin \
replace into tbl_fts(rowid, name, uid)
values(new.rowid<http://new.rowid>,new.name<http://new.name>,new.uid<http://new.uid>);\
end;"
};
int i, j, rc, cnt;
cnt = sizeof(schemas) / sizeof(char*);
char *errMsg;
for (i = 0; i < cnt; i++) {
rc = sqlite3_exec(db, schemas[i], NULL, NULL, &errMsg);
if (rc != SQLITE_OK&&rc != SQLITE_DONE) {
printf("prepareSchema error: %s\n", errMsg);
return;
}
}
printf("prepareSchema over\n");
}
void fts5_prefix_match_test() {
sqlite3 *db;
int i, j, k, rc;
char *errMsg;
char *append = "abcdefghijklmnopqrstuvwxyz";
sqlite3_open("a.db<http://a.db>", &db);
prepareSchema_prefix(db);
int test_cnt = 300, rc_copy = 0;
char zSql[2048];
char *tmp;
const int len_zSql = 2047;
int len_left;
int nRow = 0, nCol = 0;
char **pazResult;
const int trx_cnt = 10000;
int trx_idx;
for (trx_idx = 0; trx_idx < 10000; trx_idx++) {
for (i = 0; i < test_cnt; i++) {
j = random(6);
len_left = len_zSql;
tmp = zSql;
if (j < 4) {
int uid = id[j] + random(300);
rc_copy = snprintf(tmp, len_left, "insert into tbl
values(\"%s%c\",%d,\"%s%c\");",
orgName[j], append[random(26)], uid, nickName[j], append[random(26)]);
//printf("%s\n", zSql);
rc = sqlite3_exec(db, zSql, NULL, NULL, &errMsg);
if (rc != SQLITE_OK&&rc != SQLITE_DONE) {
if (rc != SQLITE_CONSTRAINT) {
printf("error %s: %s\n", zSql, errMsg);
continue;
}
else {
rc_copy = snprintf(tmp, len_left, "update tbl set name=\"%s%c\" where uid=%d\n",
orgName[j], append[random(26)], uid);
rc = sqlite3_exec(db, zSql, NULL, NULL, &errMsg);
if (rc != SQLITE_OK&&rc != SQLITE_DONE) {
printf("error %s: %s\n", zSql, errMsg);
continue;
}
}
}
}
else {
rc_copy = snprintf(zSql, len_zSql, "select * from tbl where uid=%d;", id[j]);
rc = sqlite3_get_table(db, zSql, &pazResult, &nRow, &nCol, &errMsg);
if (nRow == 0) {
rc_copy = snprintf(tmp, len_left, "insert into tbl(name, uid, nick)
values(\"%s\",%d,\"%s\");",
orgName[j], id[j], nickName[j]);
}
else {
rc_copy = snprintf(zSql, len_zSql, "update tbl set name=\"%s\" where uid=%d;",
orgName[j], id[j]);
}
rc = sqlite3_exec(db, zSql, NULL, NULL, &errMsg);
if (rc != SQLITE_OK&&rc != SQLITE_DONE) {
printf("error %s: %s\n", zSql, errMsg);
continue;
}
}
}
printf("insert 300 records\n");
sqlite3_sleep(200);
}
}
unsigned __stdcall writeFunc(void *pIn) {
fts5_prefix_match_test();
printf("write over\n");
return 0;
}
unsigned __stdcall readFunc(void *pIn) {
sqlite3 *db;
int i, j, rc;
char *errMsg;
char **pazResult;
int nRow, nCol;
sqlite3_sleep(2000);
rc = sqlite3_open("a.db<http://a.db>", &db);
if (rc != SQLITE_OK) {
printf("open db error\n");
return 0;
}
char *zSql = "select rowid, * from tbl_fts where tbl_fts match \'lucy*\';";
while (1) {
rc = sqlite3_get_table(db, zSql, &pazResult, &nRow, &nCol, &errMsg);
if (nRow > 2) {
printf("mis-match\n");
for (i = 0; i <= nRow; i++) {
for (j = 0; j < nCol; j++) {
printf("%s\t", pazResult[i*nCol + j]);
}
printf("\n");
}
return 0;
}
else {
printf("match cnt = %d\n", nRow);
}
sqlite3_free_table(pazResult);
sqlite3_sleep(3000);
}
return 0;
}
#define THREAD_NUM 2
int thread(ThreadFuncType writeFunc, ThreadFuncType readFunc) {
HANDLE handle[THREAD_NUM];
if (writeFunc) {
handle[0] = (HANDLE)_beginthreadex(NULL, 0, writeFunc, NULL, 0, NULL);
//WaitForMultipleObjects(1, handle, TRUE, INFINITE);
}
if (readFunc) {
for (int i = 1; i < THREAD_NUM; i++) {
handle[i] = (HANDLE)_beginthreadex(NULL, 0, readFunc, NULL, 0, NULL);
Sleep(5);
}
if (writeFunc) {
WaitForMultipleObjects(THREAD_NUM, &handle[0], TRUE, INFINITE);
}
else {
WaitForMultipleObjects(THREAD_NUM - 1, &handle[1], TRUE, INFINITE);
}
printf("multithread are all over now.\n");
}
else {
WaitForMultipleObjects(1, &handle[0], TRUE, INFINITE);
printf("multithread are all over now.\n");
}
return 0;
}
int main() {
thread(writeFunc, readFunc);
return 0;
}
?取 Outlook for Android<https://aka.ms/ghei36>
________________________________
From: sqlite-users <sqlite-users-boun...@mailinglists.sqlite.org> on behalf of Dan
Kennedy <danielk1...@gmail.com>
Sent: Tuesday, March 20, 2018 7:49:37 PM
To: sqlite-users@mailinglists.sqlite.org
Subject: Re: [sqlite] SQLITE3 FTS5 prefix query get mismatch result
On 03/20/2018 02:31 PM, zheng xiaojin wrote:
(I am not sure whether you have seen my message, so resend again)
Hi,
When I use FTS5, I have met that, there are some cases which will get mis-match
results with prefix search.
Like "select * from tbl_fts where tbl_fts match 'lucy*';"，which I want to get records like
"lucya","lucyabc" etc, and
"lux" or "lulu" is not what I want but returned.
Such problems are not common, But I have tried to build such test case which
can lead to this problem very easy.
Thanks for looking into and reporting this problem. Are you able to post
the source for the program you used to execute the test described below?
Dan.
Here is how I generate it:
1) create an fts5 table. and insert some record like "lucya","lucyb".
2) prepare some records: a) lusheng b)lulu; c)lunix; d)luma; e) pengyu. a,b,c,d
are have some same prefix(lu), e is some other random case.
3) before insert into the fts table with 2) records, appending some random
letter to make each record different.
Like: "lulu","luluabc","luluefg", also "lunix","lunixabc",etc
4) for-loop insert, and each loop trying to lantch the query 'lucy*', \
check the match result will finding the mis-match result, the corrent results should be
"lucya","lucyb", not "luluabc"...
When mis-match happen, I try to analyze the prefix search mechanism and find
that, there are 2 points which I think have problems:
1) fts5LeafSeek, when search failed, and exec goto search_failed, in
search_failed, the 2 if condition will not satisfy commonly. In my mind, I
think it should return,
but not, and then the search_success logic exec.
2) fts5SetupPrefixIter, when gather results, the logic to set the flag bNewTerm
has some leak, which will set bNewTerm=false,
but the record is not what we want indeed.
These 2 logic problems lead to mis-match results. I try to remove the bNewTerm
logic directly, and make it compare every loog,
then, the mis-match results disappear.
// relevant code
Change below
if (bNewTerm) {
if (nTerm < nToken || memcmp(pToken, pTerm, nToken)) break;
}
to
if (nTerm < nToken || memcmp(pToken, pTerm, nToken)) break;
Need your help to recheck the FTS5 prefix search logic, thank you very much.
Yours,
xiaojin zheng
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