使用 OCI 获取 long-raw 时程序崩溃
Program crashes when fetching long-raw with OCI
我正在尝试使用 OCI 库 SELECT Oracle table 中的一个 LONG RAW 列。
由于超出这个问题范围的原因，我更喜欢分段获取数据，而不是使用回调。
语句returns的执行，如预期的那样，OCI_NEED_DATA但是第一次调用OCIStmtFetch导致系统错误。
ErrorCode 5：访问冲突读取地址 0 in oracommon12.dll.
我有客户端 12.1 并连接到 Oracle 10.g
下面是重现错误的最小程序。
一切顺利，直到第 43 行（结果 10）：它打印 99 等于 'OCI_NEED_DATA'.
之后程序崩溃了。
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <oci.h>
static const char uid[] = "XXXX";
static const char pswd[] = "XXXX";
static const char conn[] = "XXXX";
static const char fileid[] = "XXXX";
int main(int argc, char argv[])
{
OCIEnv* p_env;
OCIError* p_err;
OCISvcCtx* p_svc;
OCIStmt* p_sql;
OCIDefine* p_dfn;
OCIBind* p_bnd;
int rc;
char stmt[256];
ub1 buffer[8192];
rc = OCIInitialize(OCI_DEFAULT, NULL, (dvoid* (*)(dvoid*, size_t))NULL, (dvoid* (*)(dvoid*, dvoid*, size_t))NULL, (void (*)(dvoid*, dvoid*))NULL);
printf("RESULT 1: %d\n", rc);
rc = OCIEnvInit(&p_env, OCI_DEFAULT, 0, NULL);
printf("RESULT 2: %d\n", rc);
rc = OCIHandleAlloc(p_env, (void**)&p_err, OCI_HTYPE_ERROR, 0, NULL);
printf("RESULT 3: %d\n", rc);
rc = OCIHandleAlloc(p_env, (void**)&p_svc, OCI_HTYPE_SVCCTX, 0, NULL);
printf("RESULT 4: %d\n", rc);
rc = OCILogon(p_env, p_err, &p_svc, (text*)uid, (ub4)strlen(uid), (text*)pswd, (ub4)strlen(pswd), (text*)conn, (ub4)strlen(conn));
printf("RESULT 5: %d\n", rc);
rc = OCIHandleAlloc(p_env, (void**)&p_sql, OCI_HTYPE_STMT, 0, NULL);
printf("RESULT 6: %d\n", rc);
sprintf(stmt, "SELECT content FROM td_planimetrie WHERE id_file = :x");
rc = OCIStmtPrepare(p_sql, p_err, (text*)stmt, (ub4)strlen(stmt), OCI_NTV_SYNTAX, OCI_DEFAULT);
printf("RESULT 7: %d\n", rc);
rc = OCIBindByName(p_sql, &p_bnd, p_err, (text*)":x", -1, (text*)fileid, (sb4)strlen(fileid) + 1, SQLT_STR, NULL, NULL, NULL, 0, NULL, OCI_DEFAULT);
printf("RESULT 8: %d\n", rc);
rc = OCIDefineByPos(p_sql, &p_dfn, p_err, 1, NULL, 0, SQLT_LBI, NULL, NULL, NULL, OCI_DYNAMIC_FETCH);
printf("RESULT 9: %d\n", rc);
rc = OCIStmtExecute(p_svc, p_sql, p_err, 1, 0, NULL, NULL, OCI_DEFAULT);
printf("RESULT 10: %d\n", rc); // <-- rc equals 99=OCI_NEED_DATA
rc = OCIStmtFetch(p_sql, p_err, 1, 0, OCI_DEFAULT); // <-- This crashes
printf("RESULT 11: %d\n", rc);
while (rc == OCI_NEED_DATA)
{
void* hndlp;
ub4 type;
ub1 in_out;
ub4 iter;
ub4 idx;
ub1 piece;
ub4 alen;
printf("RESULT 12a\n");
rc = OCIStmtGetPieceInfo(p_sql, p_err, &hndlp, &type, &in_out, &iter, &idx, &piece);
printf("RESULT 12b %d, %d, %d, %d, %d, %d\n", (int)rc, (int)type, (int)in_out, (int)iter, (int)idx, (int)piece);
alen = sizeof(buffer);
rc = OCIStmtSetPieceInfo(hndlp, type, p_err, buffer, &alen, piece, NULL, NULL);
printf("RESULT 12c %d, %d\n", (int)rc, (int)alen);
rc = OCIStmtFetch(p_sql, p_err, 1, OCI_FETCH_NEXT, OCI_DEFAULT);
printf("RESULT 12d: %d\n", rc);
}
printf("RESULT 13: %d\n", rc);
rc = OCILogoff(p_svc, p_err);
rc = OCIHandleFree(p_sql, OCI_HTYPE_STMT);
rc = OCIHandleFree(p_svc, OCI_HTYPE_SVCCTX);
rc = OCIHandleFree(p_err, OCI_HTYPE_ERROR);
return (0);
} // main
我自己想出来了：
首先，调用OCIStmtExecute中的参数iters必须设置为0。
这避免了崩溃，但没有解决整个问题。
此外，调用 OCIDefineByPos 中的参数 value_sz 必须设置为正在读取的列的实际大小。
最后，作为 OCIStmtSetPieceInfo 的第 4 个参数传递的缓冲区只能在连续调用 OCIStmtFetch 后读取。
这导致以下代码：
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <oci.h>
static const char uid[] = "XXXX";
static const char pswd[] = "XXXX";
static const char conn[] = "XXXX";
static const char fileid[] = "XXXX";
int main(int argc, char argv[])
{
OCIEnv* p_env;
OCIError* p_err;
OCISvcCtx* p_svc;
OCIStmt* p_sql;
OCIDefine* p_dfn;
OCIBind* p_bnd;
int rc;
char stmt[256];
unsigned char buffer[8192];
int counter;
long filesize;
// Connect to DB
rc = OCIInitialize(OCI_DEFAULT, NULL, (dvoid* (*)(dvoid*, size_t))NULL, (dvoid* (*)(dvoid*, dvoid*, size_t))NULL, (void (*)(dvoid*, dvoid*))NULL);
printf("RESULT 1: %d\n", rc);
rc = OCIEnvInit(&p_env, OCI_DEFAULT, 0, NULL);
printf("RESULT 2: %d\n", rc);
rc = OCIHandleAlloc(p_env, (void**)&p_err, OCI_HTYPE_ERROR, 0, NULL);
printf("RESULT 3: %d\n", rc);
rc = OCIHandleAlloc(p_env, (void**)&p_svc, OCI_HTYPE_SVCCTX, 0, NULL);
printf("RESULT 4: %d\n", rc);
rc = OCILogon(p_env, p_err, &p_svc, (text*)uid, (ub4)strlen(uid), (text*)pswd, (ub4)strlen(pswd), (text*)conn, (ub4)strlen(conn));
printf("RESULT 5: %d\n", rc);
// Determine size of data
rc = OCIHandleAlloc(p_env, (void**)&p_sql, OCI_HTYPE_STMT, 0, NULL);
printf("RESULT 6: %d\n", rc);
sprintf(stmt, "SELECT filesize FROM td_planimetrie WHERE id_file = :x");
rc = OCIStmtPrepare(p_sql, p_err, (text*)stmt, (ub4)strlen(stmt), OCI_NTV_SYNTAX, OCI_DEFAULT);
printf("RESULT 6a: %d\n", rc);
rc = OCIBindByName(p_sql, &p_bnd, p_err, (text*)":x", -1, (text*)fileid, (sb4)strlen(fileid) + 1, SQLT_STR, NULL, NULL, NULL, 0, NULL, OCI_DEFAULT);
printf("RESULT 6b: %d\n", rc);
rc = OCIDefineByPos(p_sql, &p_dfn, p_err, 1, &filesize, sizeof(filesize), SQLT_INT, NULL, NULL, NULL, OCI_DEFAULT);
printf("RESULT 6c: %d\n", rc);
rc = OCIStmtExecute(p_svc, p_sql, p_err, 1, 0, NULL, NULL, OCI_DEFAULT);
printf("RESULT 6d: %d %ld\n", rc, filesize);
rc = OCIHandleFree(p_sql, OCI_HTYPE_STMT);
printf("RESULT 6d: %d\n", rc);
// Prepare reading data
rc = OCIHandleAlloc(p_env, (void**)&p_sql, OCI_HTYPE_STMT, 0, NULL);
printf("RESULT 7: %d\n", rc);
sprintf(stmt, "SELECT content FROM td_planimetrie WHERE id_file = :x");
rc = OCIStmtPrepare(p_sql, p_err, (text*)stmt, (ub4)strlen(stmt), OCI_NTV_SYNTAX, OCI_DEFAULT);
printf("RESULT 7a: %d\n", rc);
rc = OCIBindByName(p_sql, &p_bnd, p_err, (text*)":x", -1, (text*)fileid, (sb4)strlen(fileid) + 1, SQLT_STR, NULL, NULL, NULL, 0, NULL, OCI_DEFAULT);
printf("RESULT 8: %d\n", rc);
rc = OCIDefineByPos(p_sql, &p_dfn, p_err, 1, NULL, filesize, SQLT_LBI, NULL, NULL, NULL, OCI_DYNAMIC_FETCH);
printf("RESULT 9: %d\n", rc);
rc = OCIStmtExecute(p_svc, p_sql, p_err, 0, 0, NULL, NULL, OCI_DEFAULT);
printf("RESULT 10: %d\n", rc);
rc = OCIStmtFetch(p_sql, p_err, 1, 0, OCI_DEFAULT);
printf("RESULT 11: %d\n", rc);
// Read data
unsigned long size_left = filesize;
while (rc == OCI_NEED_DATA)
{
void* hndlp;
ub4 type;
ub1 in_out;
ub4 iter;
ub4 idx;
ub1 piece;
ub4 alen;
rc = OCIStmtGetPieceInfo(p_sql, p_err, &hndlp, &type, &in_out, &iter, &idx, &piece);
printf("RESULT 12a %d, %d, %d, %d, %d, %d\n", (int)rc, (int)type, (int)in_out, (int)iter, (int)idx, (int)piece);
alen = sizeof(buffer);
memset(buffer, 0xDA, sizeof(buffer)); // some arbitrary data .....
rc = OCIStmtSetPieceInfo(hndlp, type, p_err, buffer, &alen, piece, NULL, NULL);
printf("RESULT 12b %d, %d\n", (int)rc, (int)alen);
rc = OCIStmtFetch(p_sql, p_err, 1, OCI_DEFAULT, OCI_DEFAULT);
printf("RESULT 12c: %d\n", rc);
// We can use the buffer over here
long nr_read = (size_left < alen) ? size_left : alen;
// save 'nr_read' bytes within the buffer
size_left -= nr_read;
}
printf("Size left: %lu\n", size_left);
// Cleaning up...
rc = OCILogoff(p_svc, p_err);
rc = OCIHandleFree(p_sql, OCI_HTYPE_STMT);
rc = OCIHandleFree(p_svc, OCI_HTYPE_SVCCTX);
rc = OCIHandleFree(p_err, OCI_HTYPE_ERROR);
return (0);
} // main
我正在尝试使用 OCI 库 SELECT Oracle table 中的一个 LONG RAW 列。
由于超出这个问题范围的原因，我更喜欢分段获取数据，而不是使用回调。
语句returns的执行，如预期的那样，OCI_NEED_DATA但是第一次调用OCIStmtFetch导致系统错误。
ErrorCode 5：访问冲突读取地址 0 in oracommon12.dll.
我有客户端 12.1 并连接到 Oracle 10.g
下面是重现错误的最小程序。
一切顺利，直到第 43 行（结果 10）：它打印 99 等于 'OCI_NEED_DATA'.
之后程序崩溃了。
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <oci.h>
static const char uid[] = "XXXX";
static const char pswd[] = "XXXX";
static const char conn[] = "XXXX";
static const char fileid[] = "XXXX";
int main(int argc, char argv[])
{
OCIEnv* p_env;
OCIError* p_err;
OCISvcCtx* p_svc;
OCIStmt* p_sql;
OCIDefine* p_dfn;
OCIBind* p_bnd;
int rc;
char stmt[256];
ub1 buffer[8192];
rc = OCIInitialize(OCI_DEFAULT, NULL, (dvoid* (*)(dvoid*, size_t))NULL, (dvoid* (*)(dvoid*, dvoid*, size_t))NULL, (void (*)(dvoid*, dvoid*))NULL);
printf("RESULT 1: %d\n", rc);
rc = OCIEnvInit(&p_env, OCI_DEFAULT, 0, NULL);
printf("RESULT 2: %d\n", rc);
rc = OCIHandleAlloc(p_env, (void**)&p_err, OCI_HTYPE_ERROR, 0, NULL);
printf("RESULT 3: %d\n", rc);
rc = OCIHandleAlloc(p_env, (void**)&p_svc, OCI_HTYPE_SVCCTX, 0, NULL);
printf("RESULT 4: %d\n", rc);
rc = OCILogon(p_env, p_err, &p_svc, (text*)uid, (ub4)strlen(uid), (text*)pswd, (ub4)strlen(pswd), (text*)conn, (ub4)strlen(conn));
printf("RESULT 5: %d\n", rc);
rc = OCIHandleAlloc(p_env, (void**)&p_sql, OCI_HTYPE_STMT, 0, NULL);
printf("RESULT 6: %d\n", rc);
sprintf(stmt, "SELECT content FROM td_planimetrie WHERE id_file = :x");
rc = OCIStmtPrepare(p_sql, p_err, (text*)stmt, (ub4)strlen(stmt), OCI_NTV_SYNTAX, OCI_DEFAULT);
printf("RESULT 7: %d\n", rc);
rc = OCIBindByName(p_sql, &p_bnd, p_err, (text*)":x", -1, (text*)fileid, (sb4)strlen(fileid) + 1, SQLT_STR, NULL, NULL, NULL, 0, NULL, OCI_DEFAULT);
printf("RESULT 8: %d\n", rc);
rc = OCIDefineByPos(p_sql, &p_dfn, p_err, 1, NULL, 0, SQLT_LBI, NULL, NULL, NULL, OCI_DYNAMIC_FETCH);
printf("RESULT 9: %d\n", rc);
rc = OCIStmtExecute(p_svc, p_sql, p_err, 1, 0, NULL, NULL, OCI_DEFAULT);
printf("RESULT 10: %d\n", rc); // <-- rc equals 99=OCI_NEED_DATA
rc = OCIStmtFetch(p_sql, p_err, 1, 0, OCI_DEFAULT); // <-- This crashes
printf("RESULT 11: %d\n", rc);
while (rc == OCI_NEED_DATA)
{
void* hndlp;
ub4 type;
ub1 in_out;
ub4 iter;
ub4 idx;
ub1 piece;
ub4 alen;
printf("RESULT 12a\n");
rc = OCIStmtGetPieceInfo(p_sql, p_err, &hndlp, &type, &in_out, &iter, &idx, &piece);
printf("RESULT 12b %d, %d, %d, %d, %d, %d\n", (int)rc, (int)type, (int)in_out, (int)iter, (int)idx, (int)piece);
alen = sizeof(buffer);
rc = OCIStmtSetPieceInfo(hndlp, type, p_err, buffer, &alen, piece, NULL, NULL);
printf("RESULT 12c %d, %d\n", (int)rc, (int)alen);
rc = OCIStmtFetch(p_sql, p_err, 1, OCI_FETCH_NEXT, OCI_DEFAULT);
printf("RESULT 12d: %d\n", rc);
}
printf("RESULT 13: %d\n", rc);
rc = OCILogoff(p_svc, p_err);
rc = OCIHandleFree(p_sql, OCI_HTYPE_STMT);
rc = OCIHandleFree(p_svc, OCI_HTYPE_SVCCTX);
rc = OCIHandleFree(p_err, OCI_HTYPE_ERROR);
return (0);
} // main
我自己想出来了：
首先，调用OCIStmtExecute中的参数iters必须设置为0。
这避免了崩溃，但没有解决整个问题。
此外，调用 OCIDefineByPos 中的参数 value_sz 必须设置为正在读取的列的实际大小。
最后，作为 OCIStmtSetPieceInfo 的第 4 个参数传递的缓冲区只能在连续调用 OCIStmtFetch 后读取。
这导致以下代码：
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <oci.h>
static const char uid[] = "XXXX";
static const char pswd[] = "XXXX";
static const char conn[] = "XXXX";
static const char fileid[] = "XXXX";
int main(int argc, char argv[])
{
OCIEnv* p_env;
OCIError* p_err;
OCISvcCtx* p_svc;
OCIStmt* p_sql;
OCIDefine* p_dfn;
OCIBind* p_bnd;
int rc;
char stmt[256];
unsigned char buffer[8192];
int counter;
long filesize;
// Connect to DB
rc = OCIInitialize(OCI_DEFAULT, NULL, (dvoid* (*)(dvoid*, size_t))NULL, (dvoid* (*)(dvoid*, dvoid*, size_t))NULL, (void (*)(dvoid*, dvoid*))NULL);
printf("RESULT 1: %d\n", rc);
rc = OCIEnvInit(&p_env, OCI_DEFAULT, 0, NULL);
printf("RESULT 2: %d\n", rc);
rc = OCIHandleAlloc(p_env, (void**)&p_err, OCI_HTYPE_ERROR, 0, NULL);
printf("RESULT 3: %d\n", rc);
rc = OCIHandleAlloc(p_env, (void**)&p_svc, OCI_HTYPE_SVCCTX, 0, NULL);
printf("RESULT 4: %d\n", rc);
rc = OCILogon(p_env, p_err, &p_svc, (text*)uid, (ub4)strlen(uid), (text*)pswd, (ub4)strlen(pswd), (text*)conn, (ub4)strlen(conn));
printf("RESULT 5: %d\n", rc);
// Determine size of data
rc = OCIHandleAlloc(p_env, (void**)&p_sql, OCI_HTYPE_STMT, 0, NULL);
printf("RESULT 6: %d\n", rc);
sprintf(stmt, "SELECT filesize FROM td_planimetrie WHERE id_file = :x");
rc = OCIStmtPrepare(p_sql, p_err, (text*)stmt, (ub4)strlen(stmt), OCI_NTV_SYNTAX, OCI_DEFAULT);
printf("RESULT 6a: %d\n", rc);
rc = OCIBindByName(p_sql, &p_bnd, p_err, (text*)":x", -1, (text*)fileid, (sb4)strlen(fileid) + 1, SQLT_STR, NULL, NULL, NULL, 0, NULL, OCI_DEFAULT);
printf("RESULT 6b: %d\n", rc);
rc = OCIDefineByPos(p_sql, &p_dfn, p_err, 1, &filesize, sizeof(filesize), SQLT_INT, NULL, NULL, NULL, OCI_DEFAULT);
printf("RESULT 6c: %d\n", rc);
rc = OCIStmtExecute(p_svc, p_sql, p_err, 1, 0, NULL, NULL, OCI_DEFAULT);
printf("RESULT 6d: %d %ld\n", rc, filesize);
rc = OCIHandleFree(p_sql, OCI_HTYPE_STMT);
printf("RESULT 6d: %d\n", rc);
// Prepare reading data
rc = OCIHandleAlloc(p_env, (void**)&p_sql, OCI_HTYPE_STMT, 0, NULL);
printf("RESULT 7: %d\n", rc);
sprintf(stmt, "SELECT content FROM td_planimetrie WHERE id_file = :x");
rc = OCIStmtPrepare(p_sql, p_err, (text*)stmt, (ub4)strlen(stmt), OCI_NTV_SYNTAX, OCI_DEFAULT);
printf("RESULT 7a: %d\n", rc);
rc = OCIBindByName(p_sql, &p_bnd, p_err, (text*)":x", -1, (text*)fileid, (sb4)strlen(fileid) + 1, SQLT_STR, NULL, NULL, NULL, 0, NULL, OCI_DEFAULT);
printf("RESULT 8: %d\n", rc);
rc = OCIDefineByPos(p_sql, &p_dfn, p_err, 1, NULL, filesize, SQLT_LBI, NULL, NULL, NULL, OCI_DYNAMIC_FETCH);
printf("RESULT 9: %d\n", rc);
rc = OCIStmtExecute(p_svc, p_sql, p_err, 0, 0, NULL, NULL, OCI_DEFAULT);
printf("RESULT 10: %d\n", rc);
rc = OCIStmtFetch(p_sql, p_err, 1, 0, OCI_DEFAULT);
printf("RESULT 11: %d\n", rc);
// Read data
unsigned long size_left = filesize;
while (rc == OCI_NEED_DATA)
{
void* hndlp;
ub4 type;
ub1 in_out;
ub4 iter;
ub4 idx;
ub1 piece;
ub4 alen;
rc = OCIStmtGetPieceInfo(p_sql, p_err, &hndlp, &type, &in_out, &iter, &idx, &piece);
printf("RESULT 12a %d, %d, %d, %d, %d, %d\n", (int)rc, (int)type, (int)in_out, (int)iter, (int)idx, (int)piece);
alen = sizeof(buffer);
memset(buffer, 0xDA, sizeof(buffer)); // some arbitrary data .....
rc = OCIStmtSetPieceInfo(hndlp, type, p_err, buffer, &alen, piece, NULL, NULL);
printf("RESULT 12b %d, %d\n", (int)rc, (int)alen);
rc = OCIStmtFetch(p_sql, p_err, 1, OCI_DEFAULT, OCI_DEFAULT);
printf("RESULT 12c: %d\n", rc);
// We can use the buffer over here
long nr_read = (size_left < alen) ? size_left : alen;
// save 'nr_read' bytes within the buffer
size_left -= nr_read;
}
printf("Size left: %lu\n", size_left);
// Cleaning up...
rc = OCILogoff(p_svc, p_err);
rc = OCIHandleFree(p_sql, OCI_HTYPE_STMT);
rc = OCIHandleFree(p_svc, OCI_HTYPE_SVCCTX);
rc = OCIHandleFree(p_err, OCI_HTYPE_ERROR);
return (0);
} // main