Re: [sqlite] first few characters of varchar() corrupted when SELECTing from a C++ program?
(embarrassed)
printf("testValue=(%s)\n", testValue);
From: John Machin <sjmac...@lexicon.net>
To: General Discussion of SQLite Database <sqlite-users@sqlite.org>
Sent: Tuesday, 30 June, 2009 4:51:09 PM
Subject: Re: [sqlite] first few characters of varchar() corrupted when
SELECTing from a C++ program?
On 30/06/2009 2:56 PM, freshie2004-sql...@yahoo.com.au wrote:
> printf("testValue=(%s)\n");
I've always been afraid to use those new-fangled mind-reading C
compilers lest they were easily shocked ;-)
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Re: [sqlite] first few characters of varchar() corrupted when SELECTing from a C++ program?
On 30/06/2009 2:56 PM, freshie2004-sql...@yahoo.com.au wrote:
> printf("testValue=(%s)\n");
I've always been afraid to use those new-fangled mind-reading C
compilers lest they were easily shocked ;-)
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Re: [sqlite] first few characters of varchar() corrupted when SELECTing from a C++ program?
(Replying to pierr as I joined the list after uralmazamog sent original email)
uralmazamog,
The code is incomplete. You are not showing us how you are determining what
testValue points to.
What is returned if you use the following?
sqlite3_open_v2( "testdat", sqlDB, SQLITE_OPEN_READWRITE |
SQLITE_OPEN_CREATE, NULL );
sqlite3_prepare_v2( sqlDB, "SELECT b FROM whee WHERE a='bing';",
-1,sqlStat, NULL );
sqlite3_step( sqlStat );
const unsigned char *testValue = sqlite3_column_text( sqlStat, 0 );
printf("testValue=(%s)\n");
Cheers!
From: pierr <pierr.c...@gmail.com>
To: sqlite-users@sqlite.org
Sent: Tuesday, 30 June, 2009 2:42:16 PM
Subject: Re: [sqlite] first few characters of varchar() corrupted when
SELECTing from a C++ program?
uralmazamog wrote:
>
> Greetings,
>
> maybe it's just me being stupid, I'll best jump right to the code:
>
> sqlite3_open_v2( "testdat", sqlDB, SQLITE_OPEN_READWRITE |
> SQLITE_OPEN_CREATE, NULL );
> sqlite3_prepare_v2( sqlDB, "SELECT b FROM whee WHERE a='bing';", -1,
> sqlStat, NULL );
> sqlite3_step( sqlStat );
> const unsigned char *testValue = sqlite3_column_text( sqlStat, 0 );
>
> both a and b are varchar(20)s
>
> calling the query from the command-line tool returns the proper result
> "bang", however, running this code the value testValue shows up as ""
> for longer strings only the first four characters are corrupted, and the
> rest reads okay, what am I doing wrong?
>
>
Try this:
char testValue[20];
memcpy(testValue,sqlite3_column_text(sqlStat,0),sqlite3_column_bytes(sqlStat,0));
--
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Re: [sqlite] first few characters of varchar() corrupted when SELECTing from a C++ program?
uralmazamog wrote: > > Greetings, > > maybe it's just me being stupid, I'll best jump right to the code: > > sqlite3_open_v2( "testdat", sqlDB, SQLITE_OPEN_READWRITE | > SQLITE_OPEN_CREATE, NULL ); > sqlite3_prepare_v2( sqlDB, "SELECT b FROM whee WHERE a='bing';", -1, > sqlStat, NULL ); > sqlite3_step( sqlStat ); > const unsigned char *testValue = sqlite3_column_text( sqlStat, 0 ); > > both a and b are varchar(20)s > > calling the query from the command-line tool returns the proper result > "bang", however, running this code the value testValue shows up as " " > for longer strings only the first four characters are corrupted, and the > rest reads okay, what am I doing wrong? > > Try this: char testValue[20]; memcpy(testValue,sqlite3_column_text(sqlStat,0),sqlite3_column_bytes(sqlStat,0)); -- View this message in context: http://www.nabble.com/first-few-characters-of-varchar%28%29-corrupted-when-SELECTing-from-a-C%2B%2B-program--tp24237176p24266020.html Sent from the SQLite mailing list archive at Nabble.com. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] first few characters of varchar() corrupted when SELECTing from a C++ program?
uralmaza...@pop3.ru wrote: > sqlite3_open_v2( "testdat", sqlDB, SQLITE_OPEN_READWRITE | > SQLITE_OPEN_CREATE, NULL ); > sqlite3_prepare_v2( sqlDB, "SELECT b FROM whee WHERE a='bing';", -1, > sqlStat, NULL ); > sqlite3_step( sqlStat ); > const unsigned char *testValue = sqlite3_column_text( sqlStat, 0 ); > > both a and b are varchar(20)s > > calling the query from the command-line tool returns the proper > result "bang", however, running this code the value testValue shows > up as " " Shows up where? How do you examine the string? Are you examining testValue immediately after sqlite3_column_text call? sqlite3_column_text returns a pointer to an internal buffer that may be reused by many other calls. If you need to keep the string around for later use, you must make a copy of it right after sqlite3_column_text. Igor Tandetnik ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
