Author: wyoung
Date: Tue Jun 26 06:16:30 2007
New Revision: 1615
URL: http://svn.gna.org/viewcvs/mysqlpp?rev=1615&view=rev
Log:
- Fixed the SSQLS BLOB incompatibility! Just had to give ColData a copy
ctor, change the sql_blob typedefs to use ColData instead of
std::string, and change the operator<<() for ColData. Thus, if you use
sql_blob in your SSQLS definition, the data conversion path goes from
MYSQL_ROW data to ColData, and then is copied into the ColData field in
the SSQLS directly. The operator<<() change is needed because it used
to use ColData::c_str() in the insertion process.
- Changed cgi_jpeg example to use the new mechanism
- Updated the new SSQLS chapter section on BLOBs to reflect all this
- A few other minor changes related to all this
Modified:
trunk/Wishlist
trunk/doc/userman/userman.dbx
trunk/examples/cgi_jpeg.cpp
trunk/lib/coldata.h
trunk/lib/manip.cpp
trunk/lib/sql_types.h
Modified: trunk/Wishlist
URL:
http://svn.gna.org/viewcvs/mysqlpp/trunk/Wishlist?rev=1615&r1=1614&r2=1615&view=diff
==============================================================================
--- trunk/Wishlist (original)
+++ trunk/Wishlist Tue Jun 26 06:16:30 2007
@@ -18,11 +18,6 @@
http://lists.mysql.com/plusplus/6631
- o Create a type dedicated to holding BLOB data, then add that
- type to ColData? This would fix the SSQLS incompatibilty.
- Only other way would be to redesign the convert-via-ColData
- mechanism, which will have to wait for v3.
-
o Define HAVE_MYSQL_SSL_SET by default on Windows? Make similar
decisions for other autoconf-only macros.
@@ -254,9 +249,7 @@
some definite date, get coding and provide a patch!
o SSQLS v2. Not sure how it will look yet, but there are ideas
- in play, and patches to study. Consider removing ColData at
- the same time, as it's the culprit in SSQLS BLOB
- incompatibility.
+ in play, and patches to study.
o Figure out some way to name debug DLL and library under VC++
differently (trailing 'd'?) to prevent some problems due
Modified: trunk/doc/userman/userman.dbx
URL:
http://svn.gna.org/viewcvs/mysqlpp/trunk/doc/userman/userman.dbx?rev=1615&r1=1614&r2=1615&view=diff
==============================================================================
--- trunk/doc/userman/userman.dbx (original)
+++ trunk/doc/userman/userman.dbx Tue Jun 26 06:16:30 2007
@@ -1643,36 +1643,39 @@
<sect2>
<title>SSQLS and BLOB Columns</title>
- <para>You can't currently use SSQLS to store binary
- data.</para>
-
- <para>BLOB columns are truncated when they contain null
- characters if you store them in an SSQLS. This happens because
- to get from the raw data format returned by the MySQL database
- to an SSQLS field, the data goes through a conversion step via
- <ulink type="classref" url="ColData__Tmpl">ColData</ulink>. The
- most correct target type for a BLOB column is
- <classname>mysqlpp::sql_blob</classname>, which is
- currently an alias for <classname>std::string</classname>.
- <classname>ColData</classname> converts to that via
- <methodname>ColData::operator cchar*()</methodname>,
- which means the data is treated as a C string, so embedded
- nulls are treated as end-of-data markers. We can't just
- add an <methodname>operator std::string</methodname> to
- <classname>ColData</classname>, because that creates a bunch
- of type conversion ambiguities.</para>
-
- <para>I'm documenting this here because I don't
- see any easy fixes. The fix might require redesigning
- <classname>ColData</classname>, which would have to wait until
- v3.0. Alternately, we could possibly create a dedicated BLOB
- data type, to make the correct conversion unambiguous to
- the compiler.</para>
-
- <para>In the meantime, you will have to use
- lower-level mechanisms to deal with BLOB data. See
- <filename>examples/cgi_jpeg.cpp</filename> for the recommended
- method.</para>
+ <para>It takes special care to use SSQLS with BLOB
+ columns. It's safest to declare the column as a
+ <classname>mysqlpp::sql_blob</classname> variable. This
+ is currently a typedef alias for <ulink type="classref"
+ url="ColData__Tmpl">ColData</ulink>, which is the form the
+ data is in just before the SSQLS mechanism populates the
+ structure. Thus, you end up getting a simple copy of the
+ <classname>ColData</classname> object's contents, without
+ interference.</para>
+
+ <para>You might think you could use
+ <classname>std::string</classname> instead of
+ <classname>sql_blob</classname>, but the current
+ design of <classname>ColData</classname> converts to
+ <classname>std::string</classname> via a C string. There's
+ no way to fix that without completely redesigning either
+ <classname>ColData</classname> or the SSQLS mechanism.</para>
+
+ <para>The <classname>sql_blob</classname> typedef may be
+ changed to alias a different type in the future, so using it
+ instead of <classname>ColData</classname> ensures that your
+ code tracks these library changes automatically. Besides,
+ <classname>ColData</classname> is only intended to be an
+ internal mechanism within MySQL++. The only reason the
+ layering is so thin here is because it's the only way to
+ prevent BLOB data from being corrupted, short of redesigning
+ either SSQLS or <classname>ColData</classname>.</para>
+
+ <para>You can see this technique in action in the
+ <filename>cgi_jpeg</filename> example:</para>
+
+ <programlisting><xi:include href="cgi_jpeg.txt" parse="text"
+ xmlns:xi="http://www.w3.org/2001/XInclude"/></programlisting>
</sect2>
</sect1>
Modified: trunk/examples/cgi_jpeg.cpp
URL:
http://svn.gna.org/viewcvs/mysqlpp/trunk/examples/cgi_jpeg.cpp?rev=1615&r1=1614&r2=1615&view=diff
==============================================================================
--- trunk/examples/cgi_jpeg.cpp (original)
+++ trunk/examples/cgi_jpeg.cpp Tue Jun 26 06:16:30 2007
@@ -28,6 +28,7 @@
***********************************************************************/
#include <mysql++.h>
+#include <custom.h>
using namespace std;
using namespace mysqlpp;
@@ -36,6 +37,11 @@
#define IMG_HOST "localhost"
#define IMG_USER "root"
#define IMG_PASSWORD "nunyabinness"
+
+sql_create_2(images,
+ 1, 2,
+ mysqlpp::sql_int_unsigned, id,
+ mysqlpp::sql_blob, data)
int
main()
@@ -57,14 +63,14 @@
"directory, then" << endl;
cerr << "invoke it with a URL like this:" << endl;
cerr << endl;
- cerr << " http://server.name.com/cgi-bin/cgi_image?id=2"; <<
+ cerr << " http://server.name.com/cgi-bin/cgi_jpeg?id=2"; <<
endl;
cerr << endl;
cerr << "This will retrieve the image with ID 2." << endl;
cerr << endl;
cerr << "You will probably have to change some of the #defines "
"at the top of" << endl;
- cerr << "examples/cgi_image.cpp to allow the lookup to work." <<
+ cerr << "examples/cgi_jpeg.cpp to allow the lookup to work." <<
endl;
return 1;
}
@@ -73,14 +79,13 @@
try {
con.connect(IMG_DATABASE, IMG_HOST, IMG_USER, IMG_PASSWORD);
Query query = con.query();
- query << "SELECT data FROM images WHERE id = " << img_id;
+ query << "SELECT * FROM images WHERE id = " << img_id;
ResUse res = query.use();
if (res) {
- Row row = res.fetch_row();
- unsigned long length = row.raw_size(0);
+ images img = res.fetch_row();
cout << "Content-type: image/jpeg" << endl;
- cout << "Content-length: " << length << endl << endl;
- fwrite(row.raw_data(0), 1, length, stdout);
+ cout << "Content-length: " << img.data.length() <<
"\n\n";
+ cout << img.data;
}
else {
cout << "Content-type: text/plain" << endl << endl;
Modified: trunk/lib/coldata.h
URL:
http://svn.gna.org/viewcvs/mysqlpp/trunk/lib/coldata.h?rev=1615&r1=1614&r2=1615&view=diff
==============================================================================
--- trunk/lib/coldata.h (original)
+++ trunk/lib/coldata.h Tue Jun 26 06:16:30 2007
@@ -95,6 +95,16 @@
/// way to set the type data once the object's constructed.
ColData_Tmpl() :
null_(false)
+ {
+ }
+
+ /// \brief Copy ctor
+ ///
+ /// \param cd the other ColData_Tmpl object
+ ColData_Tmpl(const ColData_Tmpl<Str>& cd) :
+ Str(cd.data(), cd.length()),
+ type_(cd.type_),
+ null_(cd.null_)
{
}
Modified: trunk/lib/manip.cpp
URL:
http://svn.gna.org/viewcvs/mysqlpp/trunk/lib/manip.cpp?rev=1615&r1=1614&r2=1615&view=diff
==============================================================================
--- trunk/lib/manip.cpp (original)
+++ trunk/lib/manip.cpp Tue Jun 26 06:16:30 2007
@@ -211,7 +211,9 @@
{
if (dont_quote_auto || (o.rdbuf() == cout.rdbuf()) ||
(o.rdbuf() == cerr.rdbuf())) {
- return o << in.c_str();
+ // Write out the raw data. Have to do it this way in case
+ // it's a BLOB field.
+ return o.write(in.data(), in.length());
}
if (in.escape_q()) {
Modified: trunk/lib/sql_types.h
URL:
http://svn.gna.org/viewcvs/mysqlpp/trunk/lib/sql_types.h?rev=1615&r1=1614&r2=1615&view=diff
==============================================================================
--- trunk/lib/sql_types.h (original)
+++ trunk/lib/sql_types.h Tue Jun 26 06:16:30 2007
@@ -56,10 +56,10 @@
typedef std::string sql_enum;
-typedef std::string sql_blob;
-typedef std::string sql_tinyblob;
-typedef std::string sql_mediumblob;
-typedef std::string sql_longblob;
+typedef ColData sql_blob;
+typedef ColData sql_tinyblob;
+typedef ColData sql_mediumblob;
+typedef ColData sql_longblob;
typedef std::string sql_char;
typedef std::string sql_varchar;
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