Oracle8 的OCI常用函数及一部分参数说明

Oracle8的OCI常用函数

1. OCIHandleAlloc()
Purpose: This call returns a pointer to anpointer to an allocated and initialized handle.
语法原型：5个参数
sword OCIHandleAlloc( CONST dvoid * parent,
dvoid ** hndlpp,
ub4 type,
size_t xtramem_sz,
dvoid** usrmempp);

type: Specifies the type of handle tobe allocated. The allowed types are:
·OCI_HTYPE_ERROR—specifies generation of an error handle of C typeOCIError.
2. OCIHandleFree()
用途：This call explicitly deallocates a handle.
原型：2个参数
sword OCIHandleFree( dvoid* hndlp,
ub4 type );
3. OCIServerAttach()
用途: Creates an access path to a datasource for OCI operations.
原型：
sword OCIServerAttach( OCIServer* srvhp,
OCIError* errhp,
CONST text* dblink,
sb4 dblink_len,
ub4 mode );

4. OCIServerDettach()
用途：Deletes an access to a data source for OCIoperations.
原型：
Sword OCIServerDetach( OCIServer* srvhp,
OCIError* errhp,
ub4 mode );
参数：
Mode:Specifies the various modes of operation. The only valid mode is OCI_DEFAULTfor the default mode.

5. OCISessionBegin()
用途：Creates a user session and begins a user sessionfor a given server.
原型：5个参数
Sword OCISessionBegin( OCISvcCtx* svchp,
OCIError* errhp,
OCISession* usrhp,
ub4 credt,
ub4 mode )
参数：

Credt: Specifies the type of credentials touse for establishing the user session. Valid values for credt are:
·OCI_CRED_RDBMS—authenticate usinga database username and password pair as credentials. The attributesOCI_ATTR_USERNAME and OCI_ATTR_PASSWORD should be set on the user session contextbefore this call.
·OCI_CRED_EXT—authenticate usingexternal credentials. No username or password is provided.

6. OCISessionEnd()

用途：Terminates a user session context created byOCISessionBegin()
原型：4个参数
Sword OCISessionEnd ( OCISvcCtx* svchp,
OCIError* errhp,
OCISession* usrhp,
ub4 mode );
参数：
mode:The only valid mode is OCI_DEFAULT.

1. OCIStmtPrepare()
用途：This call prepares a SQL or PL/SQLstatement for execution
语法原型：6个参数
sword OCIStmtPrepare ( OCIStmt * stmtp,
OCIError* errhp,
CONST text * stmt,
ub4 stmt_len,
ub4 language,
ub4 mode);

language(IN):指明V7、V8或者native syntax，可能的值为：
·OCI_V7_SYNTAX—V7 ORACLE parsing syntax
·OCI_V8_SYNTAT—V8 ORACLE parsing syntax
·OCI_NTV_SYNTAX—syntax depends upon the version of the server.
mode(IN):
Theonly defined mode is OCI_DEFAULT for default mode.

8. OCIStmtExecute()
Purpose: This call associated anapplication request with a server.
语法原型：8个参数
Sword OCIStmtExecute( OCISvcCtx* svchp,
OCIStmt* stmtp,
OCIError* errhp,
ub4 Iters,
ub4 rowoff,
CONST OCISnapshot* snap_in,
OCISnapshot * snap_out,
ub4 mode);
参数：
Iters: For non-SELECTstatements, the number of times this statement is executed is equal to
iters-rowoff.
ForSELECT statement, if iters is non-zero, then defines must have been done forthe statement handle. The execution fetches
iters rows into these predefined buffers and prefetches more rowsdepending upon the prefetch row count. If you do not know how many rows theSELECT statement will retrieve, set iters to zero.
Thisfunction returns an error if iters = 0 for non-SELECT statement.
Rowoff:
Thestarting index from which the data in an array bind is relevant for thismultiple row execution.

9. OCIBindByPos()
用途：Creates an association between a program variableand a placeholder in a SQL statement or PL/SQL block.
原型(Syntax): 13个参数
Sword OCIBindByPos ( OCIStmt* stmtp,
OCIBind** bindpp,
OCIError* errhp,
ub4 position,
dvoid* valuep,
sb4 value_sz,
ub2 dty,
dvoid* indp,
ub2* alenp,
ub2* rcodep,
ub4 maxarr_len,
ub4* curelep,
ub4 mode);
参数：
value_sz (IN)
The size of a data value. Inthe case of an array bind, this is the maximum size of
any element possible with theactual sizes being specified in the
alenp parameter.
For descriptors, locators, orREFs, whose size is unknown to client applications use
the size of the structure you are passing in; e.g., sizeof (OCILobLocator*).

10. OCIDefineByPos()
Purpose: Associates an item in aselect-list with the type and output data buffer.
语法原型：11个参数
Sword OCIDefineByPos( OCIStmt* stmtp,
OCIDefine** defnpp,
OCIError* errhp,
ub4 position,
dvoid* valuep,
sb4 value_sz,
ub2 dty,
dvoid* indp,
ub2* rlenp,
ub2* rcodep,
ub4 mode);
当获取LOB字段时，需要定义一个OCILobLocator的指针来获取LOB定位符(查询LOB字段返回的字段值是OCILobLocator)，例如OCILobLocator* pLobLocator；OCIDefineByPos()函数获取字段值的程序变量的参数valuep，对于OCILobLocator须传递&pLobLocator，即指针的地址。

参数：
Indp: 指示器变量指针，The datatype of indicatorvariables is sb2. In the case of arrays of indicator variables, the individualarray elements should be of type sb2.
Rcodep:Pointer to array of column-level return code.字段级返回代码.
Mode:The valid modes are:
·OCI_DEFAULT—this is the default mode.
·OCI_DYNAMIC_FETCH—For applicationsrequiring dynamically allocated data at the time of fetch, this mode must beused.
11. OCIDescriptorAlloc()
Purpose: Allocates storage to holddescriptors or LOB locators.
语法原型：5个参数
sword OCIDesriptorAlloc( CONST dvoid* parenth,
dvoid** descpp,
ub4 type,
size_t xtramem_sz,
dvoid** usrmempp);

12. OCIStmtFetch()
Purpose: Fetches rows from a query.
语法原型：5个参数
Sword OCIStmtFetch( OCIStmt* stmtp, 语句句柄statement handle
OCIError* errhp, 错误句柄 error handle
ub4 nrows,
ub2 orientation,
ub4 mode);
nrows: number of rows to be fetched from the currentposition.
Orientation: Forrelease 8.0, the only acceptable value is OCI_FETCH_NEXT,

which isalso the default value.
mode: For release 8.0, pass asOCI_DEFAULT.

13. OCITransCommit()
Purpose: Commits the transaction associatedwith a specified service context.
原型:
Sword OCITransCommit( OCISvcCtx* svchp,
OCIError* errhp,
ub4 flags);

13. OCIAttrGet()
用途：This call is used to get a particularattribute of a handle.
语法原型：
Sword OCIAttrGet( CONST dvoid* trgthndlp,
ub4 trghndltyp,
dvoid* attributep,
ub4* sizep,
ub4 attrtype,

例如OCI_ATTR_ROWID，OCI_ATTR_DATA_SIZE
OCIError* errhp);

14. OCIAttrSet()
Purpose: This call is used to set a particularattribute of a handle or a descriptor.
语法原型：6个参数
Sword OCIAttrSet( dvoid* trghndlp,
ub4 trghndltyp,
dvoid* attributep,
ub4 size,
ub4 attrtype,
OCIError* errhp);

15. OCIParamGet()
用途：Returns a descriptor of a parameter specifiedby position in the describe handle or statement handle.
原型：
sword OCIParamGet( CONST dvoid* hndlpp,
ub4 htype,
OCIError* errhp,
dvoid** parmdpp,
ub4 pos );

16. OCIDescribeAny()
用途：Describes existing schema objects.
原型：
Sword OCIDescribeAny ( OCISvcCtx* svchp,
OCIError* errhp,
Dvoid* objptr,
Ub4 objnm_len,
Ub1 objptr_typ,
Ub1 info_level,
Ub1 objtyp,
OCIDescribe* dschp );

17. OCILobGetLength()
用途：Gets the length of a LOB/FILE.
语法原型：
Sword OCILobGetLength( OCISvcCtx* svchp,
OCIError* errhp,
OCILobLocator* locp,
ub4* lenp);

18. OCILobRead()
用途：Reads a portion of a LOB/FILE, as specifiedby the call, into a buffer.
语法原型(Syntax)：
Sword OCILobRead( OCISvcCtx* svchp,
OCIError* errhp,
OCILobLocator* locp,
ub4* amtp,
ub4* offset,
dvoid* bufp,
ub4 bufl,
dvoid* ctxp,
OCICallbackLobRead (cbfp)
(dvoid* ctxp,
CONST dvoid* bufp,
Ub4 len,
Ub1 piece)
Ub2 csid,
Ub1 csfrm);

参数：
amtp: On input, the number ofcharacters (for CLOBs or NCLOBs) or bytes ( for BLOBs and BFILEs) to be read.On output, the actual number of bytes or characters read. If the amount ofbytes to be read is larger than the
buffer length it is assumed that LOB isbeing read in a streamed mode from the input offset until the end of

19. OCILobWrite()
用途：Writes a buffer into a BLOB.
语法原型: 12个参数
swrod OCILobWrite( OCISvcCtx* svchp,
OCIError* errhp,
OCILobLocator* locp,
ub4* amtp,
ub4 offset,
dvoid* bufp,
ub4 buflen,
ub1 piece,
dvoid* ctxp,
OCICallbackLobWrite (cbfp)
(/*_
dvoid* ctxp,
dvoid* bufp,
ub4* lenp,
ub1* piecep */)
ub2 csid,
ub1 csfrm );

参数：

OCILobLocator* locp：为OCILobLocator的指针。
Dvoid* ctxp: the context for the callback function. Can be NULL.
20. OC

21. da

六、Oracle8i8.1.7的常用函数
1. OCIEnvCreate()函数
用途：Creates andinitializes an environment for OCI functions to work under.
原型：
Sword OCIEnvCreate( OCIEnv** envhpp,
Ub4 mode,
CONST dvoid* ctxp,
CONST dvoid* (*malocfp)
(dvoid* ctxp,
Size_t size),
CONST dvoid* (*ralocfp)
(dvoid* ctxp,
Dvoid* memptr,
Size_t size),
CONST void (*mfreefp)
(dvoid* ctxp,
Dvoid* memptr),
Size_t xtramemesz,
Dvoid** usrmempp );

七、OCI的句柄和描述符属性
1. dfds
2. d

1. Service Context Handle Attributes 服务上下文句柄属性
OCI_ATTR_SESSOIN属性
Mode: Read/Write
Description:When read, returns the pointer to the authentication context attribute of theservice.
When changed, sets the authenticationcontext attribute of the service context.
Attribute Datatype:
OCISession** (Read) / OCISession*(Write)
2.

1.
2.
3. Ser
4.
5.
6. 语句句柄属性
OCI_ATTR_ROWID
MODE: READ
描述(Discription): Returns the rowid of the current row inserted, updated or fetched in acharacter string format. If execute had been a multiple row operation then,
len should contain he iteration numberof the row
程序片段：
OCIRowid* pRowid= NULL; //声明获取ROWID的OCIRowid* 描述符
//分配ROWID描述符
nRet = OCIDescriptorAlloc( (dvoid*)pEnvHdl, (dvoid**)&pRowid, (ub4)OCI_DTYPE_ROWID, (size_t)0,

(dvoid**)0 );
//获取ROWID
nRet = OCIAttrGet( (dvoid*)pStmtHdl, (ub4)OCI_HTYPE_STMT,

(dvoid*)&pRowid, (ub4*)0,

(ub4)OCI_ATTR_ROWID， (OCIError*)pErrorHdl);
//获取当前获取到的行的ROWID
int nSize = sizeof(OCIRowid*); //获取OCIRowid的大小

2.
3.