This section contains sample source code that inserts LOB data.
The first step is to prepare a parameterized insert statement. The first parameter is a numeric key used to identify this row. The second parameter is the BLOB data.
The second parameter is specified as a SQL_LONGVARBINARY data type.
The length of the LOB data is specified in the SQL_LEN_DATA_AT_EXEC macro call.
SQLINTEGER id;
SQLCHAR image[IMAGEPART_LEN ];
SQLINTEGER cbid = 0;
SQLUINTEGER cbimage = 0;
SQLRETURN retcode;
retcode = SQLPrepare(hstmt,
(SQLCHAR *)"insert into blobtable (id, image) values (?, ?)",
SQL_NTS);
if (retcode == SQL_SUCCESS || retcode == SQL_SUCCESS_WITH_INFO)
{
// Bind the parameters.
retcode = SQLBindParameter(hstmt, 1, SQL_PARAM_INPUT,
SQL_C_SLONG, SQL_INTEGER, 10, 0, &id, 0, &cbid);
retcode = SQLBindParameter(hstmt, 2, SQL_PARAM_INPUT, SQL_C_CHAR,
SQL_LONGVARBINARY, LOBSIZE, 0, (SQLPOINTER) 2, 0,
&cbimage);
//Set the 1. parameter (id)
id = 1001;
//Set the 2. parameter (image)
cbimage = SQL_LEN_DATA_AT_EXEC(0);
Setting the length to 0 as in SQL_LEN_DATA_AT_EXEC(0) means that the length is unknown.
The next step is to insert the data. The LOB data may be very large and the data are therefore inserted in chunks.
// Execute the request
retcode = SQLExecute(hstmt);
// For the data-at-execution parameter (2. parameter)
// call SQLParamData and SQLPutData repeatedly
// to insert the BLOB data in parts.
while (retcode == SQL_NEED_DATA) {
retcode = SQLParamData(hstmt, NULL);
while (GetUserData(image, IMAGEPART_LEN )) {
SQLPutData(hstmt, image, IMAGEPART_LEN );
}
}
}