[sqlite] Update problem in use C/C++ interface

[王志刚]

Hi, I meet a problem in use c/c++ API to update a row in table.
all return value means the operate is successful, But the row have no
change at all.
and the INSERT , SELECT operation is OK.

I think maybe I'm not first one meet this problem.But I can't visit
the archive. So if anyone
here know about this problem,please help me.

the main code al follow:

wstring sql = LUPDATE Mail SET [Content] = ?1 [CurrentSize] = ?2
WHERE [MailID] = ?3;;

sqlite3_stmt *pstmt = NULL;
const char *pzTail = 0;
int nRes = SQLITE_OK;
nRes = sqlite3_prepare16_v2((sqlite3*)pDB, (void**)sql.c_str(),
sizeof(wchar_t) * sql.length(), pstmt, 0);
if (0 != nRes)
{
return -1;
}
do
{
int len = 0;
void* pdata = NULL;

//Content
pdata = (void*)pMail-m_content.c_str();
len = sizeof(wchar_t) * pMail-m_content.length();
if( SQLITE_OK != (nRes = sqlite3_bind_text16(pstmt, 1, pdata,
len, SQLITE_TRANSIENT)) )break;
//CurrentSize
if( SQLITE_OK != (nRes = sqlite3_bind_int(pstmt, 2,
pMail-m_curSize)) )break;
if( SQLITE_OK != (nRes = sqlite3_bind_int(pstmt, 3,
pMail-GetID())) )break;

if ( SQLITE_DONE != (nRes = sqlite3_step(pstmt)) ) break;
}while (0);

sqlite3_finalize(pstmt);
if(SQLITE_OK != nRes  SQLITE_DONE != nRes)
{
return -1;
}
else
{
return 0;
}


-- 
-- 
 Thanks!
王志刚
---
电话：021-62672000-2852
上海圣诺网络技术有限公司
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Re: [sqlite] Update problem in use C/C++ interface

[王志刚]

??? wrote:
 Hi, I meet a problem in use c/c++ API to update a row in table.
 all return value means the operate is successful, But the row have no
 change at all.

How do you determine this?

 the main code al follow:

wstring sql = LUPDATE Mail SET [Content] = ?1 [CurrentSize] = ?2
 WHERE [MailID] = ?3;;

There should be a comma after ?1.

Are you sure there actually exists a record with the ID you bind for
the third parameter? Note that, if there isn't, you won't get any
errors - the statement simply won't update any rows.

sqlite3_stmt *pstmt = NULL;
const char *pzTail = 0;
int nRes = SQLITE_OK;
nRes = sqlite3_prepare16_v2((sqlite3*)pDB, (void**)sql.c_str(),
 sizeof(wchar_t) * sql.length(), pstmt, 0);

Why do you need to cast pDB? What type is it declared with?

The second parameter of sqlite3_prepare16_v2 is const void*, not
void**. Your cast looks strange, though harmless. You shouldn't need
any cast at all.
--
Igor Tandetnik




about the comma after ?1. is a mistake when i paste code into mail. I
simplify some code, so miss the comma.
and i'm sure there is a record with the ID bind for the third parameter.
and the cast pDB,it's no matter.our interface declear is as void*.
-- 
 Thanks!
王志刚
---
电话：021-62672000-2852
上海圣诺网络技术有限公司
---
___
sqlite-users mailing list
sqlite-users@sqlite.org
http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users