Sti*_*sis 11 c++ sql oracle oracle-call-interface bind-variables
简洁版:
我正在寻找以下Java技术的C++ OCI改编,其中代码能够将数组数组(数组大小可以变化)绑定到非PL/SQL SELECT语句中,然后在WHERE ID IN (...)样式检查中使用结果数组.
http://rafudb.blogspot.com/2011/10/variable-inlist.html
原始问题:
我们有一个C++应用程序通过OCI与Oracle通信.我们正在尝试修复通过连接文本生成SQL查询的旧代码; 相反,我们希望尽可能多地使用绑定变量.我们提出了一个特殊的案例,即我们没有一个好的解决方案.
SELECT * FROM MyTable WHERE ID IN (1, 4, 10, 30, 93)
其中(1, 4, 10, 30, 93)一部分来自一个vector<int>或数据的其他一些灵活大小容器.如果我们知道它总是五个值,我们可以这样做:
SELECT * FROM MyTable WHERE ID IN (:1, :2, :3, :4, :5)
但它可能是一个条目,或十个,甚至可能是零.显然,如果我们将查询构建为字符串,我们可以根据需要添加尽可能多的数字,但目标是尽可能避免这种情况并坚持只绑定变量.
有没有一个很好的方法来实现这一目标？例如,在OCI中,我可以绑定一个数组然后从中进行子选择吗？
SELECT * FROM MyTable WHERE ID IN (SELECT * FROM :1)
:1OCI阵列在哪里？(可能语法不同.)有没有人有这方面的经验？示例代码将是天赐之物,因为我倾向于编写原始OCI.谢谢 :)
编辑:我想比在PL/SQL过程解析的字符串中绑定更好,如果可能的话.我相信在很多情况下我们会吹掉4000个字符的限制,而且我觉得这只是交易一种我很舒服的字符串操作,另一种我不是(我不能)调试很容易).如果可能的话,我想将一个值数组(或某种形式的数据集)绑定到一个标准SQL语句中.
编辑2:一些调查发现以下链接似乎正在做我想要的,但在Java:http: //rafudb.blogspot.com/2011/10/variable-inlist.html有谁知道如何适应这个处理C++ OCI？
Thi*_*Jet 13
此示例演示了使用集合类型的方法,在数据库中定义以传递参数列表.
SYS.ODCINumberList是适用于所有用户的标准集合类型.在示例中使用的查询只选择前100个整数(test),然后使用list in IN(...)子句过滤此整数.
#include "stdafx.h"
#include <iostream>
#include <occi.h>
using namespace oracle::occi;
using namespace std;
// Vector type to pass as parameter list
typedef vector<Number> ValueList;
int _tmain(int argc, _TCHAR* argv[])
{
Environment *env;
Connection *con;
// Note that Environment must be initialized in OBJECT mode
// to use collection mapping features.
env = Environment::createEnvironment(Environment::OBJECT);
con = env->createConnection ("test_user", "test_password", "ORACLE_TNS_NAME");
try {
Statement *stmt = con->createStatement(
"select * from "
" (select level as col from dual connect by level <= 100)"
"where "
" col in (select column_value from table(:key_list))"
);
cout << endl << endl << "Executing the block :" << endl
<< stmt->getSQL() << endl << endl;
// Create instance of vector trype defined above
// and populate it with numbers.
ValueList value_list;
value_list.push_back(Number(10));
value_list.push_back(Number(20));
value_list.push_back(Number(30));
value_list.push_back(Number(40));
// Bind vector to parameter #1 in query and treat it as SYS.ODCINumberList type.
setVector(stmt, 1, value_list, "SYS", "ODCINUMBERLIST");
ResultSet *rs = stmt->executeQuery();
while(rs->next())
std::cout << "value: " << rs->getInt(1) << std::endl;
stmt->closeResultSet(rs);
con->terminateStatement (stmt);
} catch(SQLException ex) {
cout << ex.what();
}
env->terminateConnection (con);
Environment::terminateEnvironment (env);
return 0;
}
您可以使用各种ODCIxxxList类型通过OCI将数字,日期或字符串列表传递给Oracle,甚至可以在DB中定义您自己的类型.
使用Visual Studio 10 Express和此版本的OCI库编译的示例.针对Oracle 11.2.0.3.0进行了测试.
更新
下面是使用普通C OCIxxx函数执行相同操作的示例应用程序.
//
// OCI collection parameters binding - example application
//
#include "stdafx.h"
#include <iostream>
#include <oci.h>
#include <oro.h>
using namespace std;
// connection parameters
const char *db_alias = "ORACLE_DB_ALIAS";
const char *db_user_name = "test_user";
const char *db_user_password = "test_password";
// helper error checking procedure to shorten main code, returns true if critical error detected
// and prints out error information
bool check_oci_error(char *error_point, OCIError *errhp, sword status, OCIEnv *envhp);
int _tmain(int argc, _TCHAR* argv[]) {
//----- CONNECTION INITIALIZATION PART ------------------------------------------------------
sword rc;
OCIEnv *myenvhp; /* the environment handle */
OCIServer *mysrvhp; /* the server handle */
OCIError *myerrhp; /* the error handle */
OCISession *myusrhp; /* user session handle */
OCISvcCtx *mysvchp; /* the service handle */
/* initialize the mode to be the threaded and object environment */
/* NOTE: OCI_OBJECT must be present to work with object/collection types */
rc = OCIEnvCreate(&myenvhp, OCI_THREADED|OCI_OBJECT, (dvoid *)0, 0, 0, 0, (size_t) 0, (dvoid **)0);
if( check_oci_error("OCIEnvCreate", NULL, rc, NULL) ) {
return -1;
}
/* allocate a server handle */
rc = OCIHandleAlloc ((dvoid *)myenvhp, (dvoid **)&mysrvhp, OCI_HTYPE_SERVER, 0, (dvoid **) 0);
if( check_oci_error("OCIHandleAlloc(OCI_HTYPE_SERVER)", NULL, rc, myenvhp) ) return -1;
/* allocate an error handle */
rc = OCIHandleAlloc ((dvoid *)myenvhp, (dvoid **)&myerrhp, OCI_HTYPE_ERROR, 0, (dvoid **) 0);
if( check_oci_error("OCIHandleAlloc(OCI_HTYPE_ERROR)", NULL, rc, myenvhp) ) return -1;
/* create a server context */
rc = OCIServerAttach(mysrvhp, myerrhp, (text *)db_alias, strlen (db_alias), OCI_DEFAULT);
if( check_oci_error("OCIServerAttach()", myerrhp, rc, myenvhp) ) return -1;
/* allocate a service handle */
rc = OCIHandleAlloc ((dvoid *)myenvhp, (dvoid **)&mysvchp, OCI_HTYPE_SVCCTX, 0, (dvoid **) 0);
if( check_oci_error("OCIHandleAlloc(OCI_HTYPE_SVCCTX)", myerrhp, rc, myenvhp) ) return -1;
/* set the server attribute in the service context handle*/
rc = OCIAttrSet((dvoid *)mysvchp, OCI_HTYPE_SVCCTX, (dvoid *)mysrvhp, (ub4) 0, OCI_ATTR_SERVER, myerrhp);
if( check_oci_error("OCIAttrSet(OCI_HTYPE_SVCCTX,OCI_ATTR_SERVER)", myerrhp, rc, myenvhp) ) return -1;
/* allocate a user session handle */
rc = OCIHandleAlloc((dvoid *)myenvhp, (dvoid **)&myusrhp, OCI_HTYPE_SESSION, 0, (dvoid **) 0);
if( check_oci_error("OCIHandleAlloc(OCI_HTYPE_SESSION)", myerrhp, rc, myenvhp) ) return -1;
/* set user name attribute in user session handle */
rc = OCIAttrSet((dvoid *)myusrhp, OCI_HTYPE_SESSION, (dvoid *)db_user_name, strlen(db_user_name), OCI_ATTR_USERNAME, myerrhp);
if( check_oci_error("OCIAttrSet(OCI_HTYPE_SESSION,OCI_ATTR_USERNAME)", myerrhp, rc, myenvhp) ) return -1;
/* set password attribute in user session handle */
rc = OCIAttrSet((dvoid *)myusrhp, OCI_HTYPE_SESSION, (dvoid *)db_user_password, strlen(db_user_password), OCI_ATTR_PASSWORD, myerrhp);
if( check_oci_error("OCIAttrSet(OCI_HTYPE_SESSION,OCI_ATTR_PASSWORD)", myerrhp, rc, myenvhp) ) return -1;
rc = OCISessionBegin(mysvchp, myerrhp, myusrhp, OCI_CRED_RDBMS, OCI_DEFAULT);
if( check_oci_error("OCISessionBegin()", myerrhp, rc, myenvhp) ) return -1;
/* set the user session attribute in the service context handle*/
rc = OCIAttrSet( (dvoid *)mysvchp, OCI_HTYPE_SVCCTX, (dvoid *)myusrhp, (ub4) 0, OCI_ATTR_SESSION, myerrhp);
if( check_oci_error("OCIAttrSet(OCI_HTYPE_SVCCTX,OCI_ATTR_SESSION)", myerrhp, rc, myenvhp) ) return -1;
cout << endl << "Initialization done." << endl;
//----- REGISTER TYPE INFORMATION ------------------------------------------------------
// This section can be invoked once per session to minimize server roundtrips.
char *type_owner_name = "SYS";
char *type_name = "ODCINUMBERLIST";
OCIType *type_tdo = NULL;
rc= OCITypeByName(
myenvhp, myerrhp, mysvchp,
(CONST text *)type_owner_name, strlen(type_owner_name),
(CONST text *) type_name, strlen(type_name),
NULL, 0,
OCI_DURATION_SESSION, OCI_TYPEGET_HEADER,
&type_tdo
);
if( check_oci_error("OCITypeByName()", myerrhp, rc, myenvhp) ) return -1;
//----- PREPARE PARAMETER INSTANCE ---------------------------------------------
OCIArray *array_param = NULL;
rc = OCIObjectNew(
myenvhp, myerrhp, mysvchp,
OCI_TYPECODE_VARRAY,
type_tdo, NULL, OCI_DURATION_SESSION, TRUE,
(void**) &array_param
);
if( check_oci_error("OCITypeByName()", myerrhp, rc, myenvhp) ) return -1;
//----- FILL PARAMETER ---------------------------------------------------------
OCINumber num_val;
int int_val;
for(int i = 1; i <= 3; i++) {
int_val = i*10;
rc = OCINumberFromInt(myerrhp, &int_val, sizeof(int_val), OCI_NUMBER_SIGNED, &num_val);
if( check_oci_error("OCINumberFromInt()", myerrhp, rc, myenvhp) ) return -1;
rc = OCICollAppend(myenvhp, myerrhp, &num_val, NULL, array_param);
if( check_oci_error("OCICollAppend()", myerrhp, rc, myenvhp) ) return -1;
}
//----- BIND PARAMETER VALUE AND EXECUTE STATEMENT ------------------------------
OCIStmt *mystmthp = NULL;
OCIDefine *col1defp = NULL;
double col1value;
OCIBind *bndp = NULL;
char *query_text = "select * from "
" (select level as col from dual connect by level < 100)"
"where "
" col in (select column_value from table(:key_list))";
rc = OCIHandleAlloc(myenvhp, (void **)&mystmthp, OCI_HTYPE_STMT, 0, NULL);
if( check_oci_error("OCIHandleAlloc(OCI_HTYPE_STMT)", myerrhp, rc, myenvhp) ) return -1;
rc = OCIStmtPrepare(
mystmthp, myerrhp,
(const OraText *)query_text, strlen(query_text),
OCI_NTV_SYNTAX, OCI_DEFAULT
);
if( check_oci_error("OCIStmtPrepare()", myerrhp, rc, myenvhp) ) return -1;
// result column
rc = OCIDefineByPos(mystmthp, &col1defp, myerrhp, 1, &col1value, sizeof(col1value), SQLT_BDOUBLE, NULL, NULL, NULL, OCI_DEFAULT);
if( check_oci_error("OCIDefineByPos()", myerrhp, rc, myenvhp) ) return -1;
// parameter collection
rc = OCIBindByName(
mystmthp, &bndp, myerrhp,
(text *)":key_list", strlen(":key_list"),
NULL, 0,
SQLT_NTY, NULL, 0, 0, 0, 0,
OCI_DEFAULT
);
if( check_oci_error("OCIBindByName()", myerrhp, rc, myenvhp) ) return -1;
rc = OCIBindObject(
bndp, myerrhp,
type_tdo, (dvoid **) &array_param,
NULL, NULL, NULL
);
if( check_oci_error("OCIBindByName()", myerrhp, rc, myenvhp) ) return -1;
// execute and fetch
rc = OCIStmtExecute(mysvchp, mystmthp, myerrhp, 0, 0, NULL, NULL, OCI_DEFAULT);
if( check_oci_error("OCIBindByName()", myerrhp, rc, myenvhp) ) return -1;
rc = OCIStmtFetch2(mystmthp, myerrhp, 1, OCI_FETCH_NEXT, 0, OCI_DEFAULT);
while(rc != OCI_NO_DATA) {
if( check_oci_error("OCIStmtFetch2()", myerrhp, rc, myenvhp) ) return -1;
cout << "value: " << col1value << endl;
rc = OCIStmtFetch2(mystmthp, myerrhp, 1, OCI_FETCH_NEXT, 0, OCI_DEFAULT);
}
// free collection object parameter
rc = OCIObjectFree(myenvhp, myerrhp, array_param, OCI_OBJECTFREE_FORCE);
if( check_oci_error("OCIObjectFree()", myerrhp, rc, myenvhp) ) return -1;
cout << endl << "Main test done." << endl;
//------- FINALIZATION -----------------------------------------------------------
rc= OCISessionEnd(mysvchp, myerrhp, myusrhp, OCI_DEFAULT);
if( check_oci_error("OCISessionEnd()", myerrhp, rc, myenvhp) ) return -1;
rc = OCIServerDetach(mysrvhp, myerrhp, OCI_DEFAULT);
if( check_oci_error("OCIServerDetach()", myerrhp, rc, myenvhp) ) return -1;
OCIHandleFree(myenvhp, OCI_HTYPE_ENV);
cout << endl << "Finalization done." << endl;
return 0;
}
// helper error checking procedure to shorten main code, returns true if critical error detected
// and prints out error information
bool check_oci_error(char *error_point, OCIError *errhp, sword status, OCIEnv *envhp) {
text errbuf[1024];
sb4 errcode;
bool ret_code = true;
switch (status) {
case OCI_SUCCESS:
ret_code = false;
break;
case OCI_SUCCESS_WITH_INFO:
OCIErrorGet ((dvoid *) errhp, (ub4) 1, (text *) NULL, &errcode, errbuf, (ub4) sizeof(errbuf), (ub4) OCI_HTYPE_ERROR);
cout << error_point << " Error: OCI_SUCCESS_WITH_INFO; Info: " << errbuf << endl;
ret_code = (errcode == 436 || errcode == 437 || errcode == 438 || errcode == 439);
break;
case OCI_NEED_DATA:
cout << error_point << " Error: OCI_NEED_DATA"<< endl;
break;
case OCI_NO_DATA:
cout << error_point << " Error: OCI_NO_DATA"<< endl;
break;
case OCI_ERROR:
OCIErrorGet ((dvoid *) errhp, (ub4) 1, (text *) NULL, &errcode, errbuf, (ub4) sizeof(errbuf), (ub4) OCI_HTYPE_ERROR);
cout << error_point << " Error: " << errbuf << endl;
break;
case OCI_INVALID_HANDLE:
cout << error_point << " Error: OCI_INVALID_HANDLE" << endl;
break;
case OCI_STILL_EXECUTING:
cout << error_point << " Error: OCI_STILL_EXECUTE"<< endl;
break;
case OCI_CONTINUE:
cout << error_point << " Error: OCI_CONTINUE" << endl;
break;
default:
cout << error_point << " Error: UNKNOWN(" << status << ")" << endl;
break;
}
if( ret_code && (envhp != NULL) ) OCIHandleFree(envhp, OCI_HTYPE_ENV);
return ret_code;
}
PS您可以从Oracle文档和此示例代码中获取信息.
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