基于Oracle OCI的数据访问C语言接口ORADBI .

[align=center]基于Oracle OCI的数据访问C语言接口ORADBI[/align]
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[align=center]cheungmine@gmail.com[/align]
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[align=center]Mar. 22, 2008[/align]
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ORADBI是我在Oracle OCI（Oracle 调用接口）基础上开发的，支持Oracle8i、9i、10g等数据库。根据Oracle公司的介绍：OCI是如此可靠，以至于Oracle数据库中的每一条SQL语句都通过OCI来执行。当应用程序开发人员需要面向Oracle数据库服务器的最强大的接口时，他们将调用 Oracle调用接口（OCI）。OCI提供了对所有Oracle数据库功能的最全面的访问。OCI API中包含了最新的性能、可伸缩性和安全性特性。
采用OCI的最大好处就是：它是最切近Oracle底层的技术，因此，效率是最高的。同时，它是跨平台的。因此，在我给出的ORADBI库，除了OCI之外，没有其他外部依赖，稍加改动，就可以移植到非Windows平台上或其他嵌入式平台。

然而，OCI也比较不容易使用。它的功能之强，粒度之细，语法之烦琐，都不适合今天熟悉了快速开发模式的人员使用。然而，OCI的高效，直接根植于数据库核心，跨平台的语言特性，是其他如OO4O、OLEDB、ADO等COM方式不具备的。我最初开发Oralce数据库是4年以前，使用的是OO4O。直到最近，使用OCI成了我的爱好。于是，写了一套OCI的Helper库，方便OCI的使用。我不敢说是OCI的Wrapper库，因为我没能力包装OCI的方方面面。然而，我的ORADBI已经足够我（可能也包括你们）日常使用了。我就是用这套ORADBI操纵BLOB等大数据字段的。

公布这套ORADBI库，没有任何商业上的风险：我拥有这个库的全部版权，任何个人或团体可以为任何目的免费地、无限制地使用ORADBI库，前提是不能声明对ORADBI库的版权。对使用ORADBI库所造成的任何后果，我不负任何责任。如果这套软件对您的工作产生了很大的帮助，我不拒绝任何您的资助。

好了，让我们概览一下这个库，它包含下列文件：

.h文件 .c文件
oradbi.h* oradbi.c
oracol.h oracol.c
oraconn.h oraconn.c
oradate.h oradate.c
oraerr.h oraerr.c
oraparam.h oraparam.c

orarows.h orarows.c
orastmt.h orastmt.c
oratype.h

unistd.h
list.h list.c
hashmap.h hashmap.c

其中，oradbi.h是你唯一需要包含的头文件。当把ORADBI作为动态库连接到你的工程里使用时，你在你的项目里加入类似下面的代码：

// test.cpp
#include "../oradbi/oradbi.h"

#ifdef _DEBUG
#pragma comment(lib, "../oradbi/debug/oradbid.lib")
#else
#pragma comment(lib, "../oradbi/release/oradbi.lib")
#endif

下面是oradbi.h的全部内容：

/*======================================================================
oradbi.h - Created by cheungmine, All rights reserved.
First : Mar. 8, 2008
======================================================================*/
#ifndef ORADBI_H_INCLUDED
#define ORADBI_H_INCLUDED

#ifdef __cplusplus
extern "C" {
#endif

#ifdef ORADBI_DLLEXPORT
# define ORADB_CALL __declspec(dllexport)
# define ORADB_CALL1(x) __declspec(dllexport) x
#endif

#ifndef ORADB_CALL
# define ORADB_CALL
#endif

#ifndef ORADB_CALL1
# define ORADB_CALL1(x) x ORADB_CALL
#endif

/* NOT SUPPORT UNICODE */
#ifdef UNICODE
#pragma message( __FILE__" Warning UNICODE: Cannot use UNICODE" )
#endif

/* NOT SUPPORT UNICODE */
#ifdef _UNICODE
#pragma message( __FILE__" Warning UNICODE: Cannot use UNICODE" )
#endif

#include "unistd.h"
#include "oratype.h"
#include "oraerr.h"

/*======================================================================
connection Functions - oraconn.c
======================================================================*/
/* connects the application to the oracle server. */
lresult ORADB_CALL ORA_connection_create (
OUT ora_connection *connection,
IN const char *service_name,
IN const char *username,
IN const char *password,
IN ulong env_mode, /* =OCI_THREADED|OCI_OBJECT */
IN BOOL non_blocking_mode, /* =FALSE */
OUT ora_error_t *error /* NULL for no err msg return */
);

/* disconnects the application from the oracle server. */
void ORADB_CALL ORA_connection_free (
IN ora_connection connection
);

/* executes a sql statement with no result */
lresult ORADB_CALL ORA_connection_execute (
IN ora_connection connection,
IN const char *sql_block,
IN int sql_len, /* -1 for strlen called*/
OUT ora_error_t *error /* NULL for no err msg return */
);

/* prepares (and returns) a sql statement for execution */
lresult ORADB_CALL ORA_connection_prepare (
IN ora_connection connection,
IN const char *sql_block,
IN int sql_len, /* -1 for strlen called*/
OUT ora_sqlstmt *sqlstmt, /* a sql statement for execution returned */
OUT ora_error_t *error /* NULL for no err msg return */
);

/* executes a select sql statement and return the result set */
lresult ORADB_CALL ORA_connection_select (
IN ora_connection connection,
IN const char *sql_select,
IN int sql_len, /* -1 for strlen called*/
OUT ora_rowset *rowset, /* the result set returned */
OUT ora_error_t *error /* NULL for no err msg return */
);

/* commits changes */
lresult ORADB_CALL ORA_connection_commit (
IN ora_connection connection,
OUT ora_error_t *error /* NULL for no err msg return */
);

/* rollbacks changes */
lresult ORADB_CALL ORA_connection_rollback (
IN ora_connection connection,
OUT ora_error_t *error /* NULL for no err msg return */
);

/*======================================================================
sqlstmt Functions - orastmt.c
======================================================================*/
lresult ORADB_CALL ORA_sqlstmt_create (
OUT ora_sqlstmt *sqlstmt,
IN ora_connection connection,
IN const char *sql_block,
IN int sql_len, /* -1 for strlen to be called*/
IN ushort fetch_size, /* 0 for default or bind array size for INSERT */
OUT ora_error_t *error /* NULL for no err msg return */
);

void ORADB_CALL ORA_sqlstmt_free (
IN ora_sqlstmt sqlstmt
);

/* executes a sql statement with no output parameters */
lresult ORADB_CALL ORA_sqlstmt_execute (
IN ora_sqlstmt sqlstmt,
IN ORADBI_ExecMode mode, /* execute mode: MOD_DEFAULT=0 */
IN ushort iters, /* 0 is default */
OUT ora_error_t *error /* NULL for no err msg return */
);

/* executes a select sql statement and returns the result set */
lresult ORADB_CALL ORA_sqlstmt_select (
IN ora_sqlstmt sqlstmt,
IN ORADBI_ExecMode mode, /* execute mode: MOD_DEFAULT=0 */
OUT ora_rowset *rowset,
OUT ora_error_t *error /* NULL for no err msg return */
);

/* binds a named variable to sqlstmt but for lob, when type is set to ODT_UNKNOWN type is taken from name's prefix */
lresult ORADB_CALL ORA_sqlstmt_bind (
IN ora_sqlstmt sqlstmt,
IN const char *name, /* param name bound */
IN ORADBI_DataType type, /* param type bound. set ODT_UNKNOWN for simplely. cannot be a lob type */
IN int size, /* param size for TEXT, LOB. 0 for others */
OUT ora_param *param, /* a out param bound to sqlstmt */
OUT ora_error_t *error /* NULL for no err msg return */
);

/* binds a named variable to sqlstmt only with lob type */
lresult ORADB_CALL ORA_sqlstmt_bind_lob (
IN ora_sqlstmt sqlstmt,
IN const char *name, /* param name bound */
IN int max_size, /* maximum size of lob data, 0 for default. if 0, client_data must be a valid pointer */
IN ORADBI_InBind *inbind, /* can be null. if null, max_size must be a meaningful value not more than 65535 */
IN ORADBI_OutBind *outbind, /* can be null */
OUT ora_param *param, /* a out param bound to sqlstmt */
OUT ora_error_t *error /* NULL for no err msg return */
);

/* accesses param in the sqlstmt by name. gets a reference to param */
ora_param ORADB_CALL ORA_sqlstmt_get_param_by_name (
IN ora_sqlstmt sqlstmt,
IN const char* param_name, /* MUST be a valid name string */
OUT ora_error_t *error /* NULL for no err msg return */
);

/* accesses param in the sqlstmt by index: 1-based. gets a reference to param */
ora_param ORADB_CALL ORA_sqlstmt_get_param_by_index (
IN ora_sqlstmt sqlstmt,
IN ushort param_index, /* PARAM_INDEX_BASE based */
OUT ora_error_t *error /* NULL for no err msg return */
);

/*======================================================================
rowset Functions - orarows.c
======================================================================*/
/* returns number of rows fetched so far */
lresult ORADB_CALL ORA_rowset_num_rows (
IN ora_rowset rowset,
OUT size_t *num_rows,
OUT ora_error_t *error /* NULL for no err msg return */
);

/* returns number of columns */
lresult ORADB_CALL ORA_rowset_num_columns (
IN ora_rowset rowset,
OUT size_t *num_cols,
OUT ora_error_t *error /* NULL for no err msg return */
);

/* fetches next row of record. TRUE for NOT completed; FALSE for completed */
BOOL ORADB_CALL ORA_rowset_next (
IN ora_rowset rowset
);

/* frees a ora_rowset. a freed rowset handle is an invalid pointer and cannot be used any more */
void ORADB_CALL ORA_rowset_free (
IN ora_rowset rowset
);

/* accesses column in the current row by name. gets a reference to column */
ora_column ORADB_CALL ORA_rowset_get_column_by_name (
IN ora_rowset rowset,
IN const char* col_name, /* MUST be a valid name string */
OUT ora_error_t *error /* NULL for no err msg return */
);

/* accesses column in the current row by index: 1-based. gets a reference to column */
ora_column ORADB_CALL ORA_rowset_get_column_by_index (
IN ora_rowset rowset,
IN ushort col_index, /* COLUMN_INDEX_BASE based */
OUT ora_error_t *error /* NULL for no err msg return */
);

/*======================================================================
column Functions - oracol.c
======================================================================*/
/* returns column data type */
ORADB_CALL1(const char*) ORA_column_get_name (
IN ora_column column
);

/* returns column data type */
ORADBI_DataType ORADB_CALL ORA_column_get_type (
IN ora_column column
);

/* returns column display size */
size_t ORADB_CALL ORA_column_get_dispsize (
IN ora_column column
);

/* returns column precision of numberic data type */
int ORADB_CALL ORA_column_get_precision (
IN ora_column column
);

/* returns column scale of numberic data type */
int ORADB_CALL ORA_column_get_scale (
IN ora_column column
);

/* returns whether column is null ok */
BOOL ORADB_CALL ORA_column_is_null_ok (
IN ora_column column
);

/* returns whether column value is null */
BOOL ORADB_CALL ORA_column_is_null (
IN ora_column column
);

/* returns column value as string */
lresult ORADB_CALL ORA_column_as_string (
IN ora_column column,
OUT char **outval, /* Returns address of pointer to actual data */
OUT ora_error_t *error /* NULL for no err msg return */
);

/* returns column value as double */
lresult ORADB_CALL ORA_column_as_double (
IN ora_column column,
OUT double *outval,
OUT ora_error_t *error /* NULL for no err msg return */
);

/* returns column value as float32 */
lresult ORADB_CALL ORA_column_as_float (
IN ora_column column,
OUT float *outval,
OUT ora_error_t *error /* NULL for no err msg return */
);

/* returns column value as long */
lresult ORADB_CALL ORA_column_as_long (
IN ora_column column,
OUT long *outval,
OUT ora_error_t *error /* NULL for no err msg return */
);

/* returns column value as unsigned long */
lresult ORADB_CALL ORA_column_as_ulong (
IN ora_column column,
OUT ulong *outval,
OUT ora_error_t *error /* NULL for no err msg return */
);

/* returns column value as int64 */
lresult ORADB_CALL ORA_column_as_longlong (
IN ora_column column,
OUT longlong *outval,
OUT ora_error_t *error /* NULL for no err msg return */
);

/* returns column value as uint64 */
lresult ORADB_CALL ORA_column_as_ulonglong (
IN ora_column column,
OUT ulonglong *outval,
OUT ora_error_t *error /* NULL for no err msg return */
);

/* returns column value as datetime */
lresult ORADB_CALL ORA_column_as_datetime (
IN ora_column column,
OUT ora_datetime *outval,
OUT ora_error_t *error
);

/* gets lob size for read. if a column isn't a LOB type or NULL, return 0 */
size_t ORADB_CALL ORA_column_lob_size (
IN ora_column column
);

/* read lob column value - pulling mode */
/* An example of pulling lob data with ORA_column_read_lob:
#define BUFF_SIZE 512

byte lob_buf[BUFF_SIZE];
lob_siz = ORA_column_lob_size (col);
lob_data = (byte*) malloc (lob_siz);
cb_offs = 0;
cb_read = BUFF_SIZE;

while ((rc=ORA_column_read_lob (col, lob_siz, cb_offs, lob_buf, &cb_read, &err))==ORC_NEED_DATA || rc==ORC_SUCCESS)
{
memcpy (lob_data+cb_offs, lob_buf, cb_read);
cb_offs += cb_read;
if (rc==ORC_SUCCESS)
break;
cb_read = BUFF_SIZE;
}
ASSERT (cb_offs == lob_siz);
*/
lresult ORADB_CALL ORA_column_read_lob (
IN ora_column column,
IN size_t lobsize_to_read, /* total bytes to read, usually is lob_size */
IN size_t cb_offset, /* offset bytes from the start of lob data */
INOUT byte* in_buf, /* when returned, in_buf has actual data */
INOUT size_t* cb_read, /* input is buf size and output is size of bytes be read */
OUT ora_error_t *error /* NULL for no err msg return */
);

/* returns lob column value as bytes once for all. out_buf is allocated by caller for fetch bytes.
* buf_size is size of out_buf
* ORA_column_as_bytes calls ORA_column_read_lob internally.
*/
/* An example of pulling lob data with ORA_column_as_bytes:
size_t lob_size = ORA_column_lob_size (col);
byte* out_buf = malloc (lob_size);
ORA_column_as_bytes (col, out_buf, &lob_size, NULL);
...
free (out_buf);
*/
lresult ORADB_CALL ORA_column_as_bytes (
IN ora_column column,
INOUT byte* out_buf,
INOUT size_t* lob_size, /* size bytes of lob data which must <= size of buffer */
OUT ora_error_t *error /* NULL for no err msg return */
);

/*======================================================================
param Functions - oraparam.c
======================================================================*/
ORADBI_DataType ORADB_CALL ORA_param_get_type (
IN ora_param param
);

lresult ORADB_CALL ORA_param_set_long (
IN ora_param param,
IN long val,
OUT ora_error_t *error /* NULL for no err msg return */
);

lresult ORADB_CALL ORA_param_set_ulong (
IN ora_param param,
IN ulong val,
OUT ora_error_t *error /* NULL for no err msg return */
);

lresult ORADB_CALL ORA_param_set_longlong (
IN ora_param param,
IN longlong val,
OUT ora_error_t *error /* NULL for no err msg return */
);

lresult ORADB_CALL ORA_param_set_ulonglong (
IN ora_param param,
IN ulonglong val,
OUT ora_error_t *error /* NULL for no err msg return */
);

lresult ORADB_CALL ORA_param_set_datetime (
IN ora_param param,
IN ora_datetime val,
OUT ora_error_t *error /* NULL for no err msg return */
);

void ORADB_CALL ORA_param_set_null (
IN ora_param param
);

lresult ORADB_CALL ORA_param_set_float (
IN ora_param param,
IN float val,
OUT ora_error_t *error /* NULL for no err msg return */
);

lresult ORADB_CALL ORA_param_set_double (
IN ora_param param,
IN double val,
OUT ora_error_t *error /* NULL for no err msg return */
);

lresult ORADB_CALL ORA_param_set_string (
IN ora_param param,
IN const char *val,
IN short len, /* -1 for strlen called */
OUT ora_error_t *error /* NULL for no err msg return */
);

lresult ORADB_CALL ORA_param_set_bytes (
IN ora_param param,
IN const byte *in_buf,
IN ushort size_buf,
OUT ora_error_t *error /* NULL for no err msg return */
);

BOOL ORADB_CALL ORA_param_is_null (
IN ora_param param
);

/* returns column value as string */
lresult ORADB_CALL ORA_param_as_string (
IN ora_param param,
OUT char **outval, /* Returns address of pointer to actual data */
OUT ora_error_t *error /* NULL for no err msg return */
);

/* returns param value as double */
lresult ORADB_CALL ORA_param_as_double (
IN ora_param param,
OUT double *outval,
OUT ora_error_t *error /* NULL for no err msg return */
);

/* returns param value as float32 */
lresult ORADB_CALL ORA_param_as_float (
IN ora_param param,
OUT float *outval,
OUT ora_error_t *error /* NULL for no err msg return */
);

/* returns param value as long */
lresult ORADB_CALL ORA_param_as_long (
IN ora_param param,
OUT long *outval,
OUT ora_error_t *error /* NULL for no err msg return */
);

/* returns param value as unsigned long */
lresult ORADB_CALL ORA_param_as_ulong (
IN ora_param param,
OUT ulong *outval,
OUT ora_error_t *error /* NULL for no err msg return */
);

/* returns param value as long */
lresult ORADB_CALL ORA_param_as_longlong (
IN ora_param param,
OUT longlong *outval,
OUT ora_error_t *error /* NULL for no err msg return */
);

/* returns param value as unsigned long */
lresult ORADB_CALL ORA_param_as_ulonglong (
IN ora_param param,
OUT ulonglong *outval,
OUT ora_error_t *error /* NULL for no err msg return */
);

/* returns param value as datetime */
lresult ORADB_CALL ORA_param_as_datetime (
IN ora_param param,
OUT ora_datetime *outval,
OUT ora_error_t *error /* NULL for no err msg return */
);

/* returns param value as rowset */
lresult ORADB_CALL ORA_param_as_rowset (
IN ora_param param,
OUT ora_rowset *outval,
OUT ora_error_t *error /* NULL for no err msg return */
);

/*======================================================================
datetime Functions - oradate.c
======================================================================*/
/* creates a datetime opaque pointer which must be free after using */
lresult ORADB_CALL ORA_datetime_create (
OUT ora_datetime *dt /* must be a valid pointer */
);

lresult ORADB_CALL ORA_datetime_set_all (
IN ora_datetime dt,
IN short year, /* gregorian year; range is -4712 <= year <= 9999 */
IN ORADBI_DTMonth month, /* month; range is 1 <= month < 12 */
IN byte day, /* day; range is 1 <= day <= 31 */
IN byte hours, /* hours; range is 0 <= hours <=23 */
IN byte minutes, /* minutes; range is 0 <= minutes <= 59 */
IN byte seconds, /* seconds; range is 0 <= seconds <= 59 */
OUT ora_error_t *error /* NULL for no err msg return */
);

void ORADB_CALL ORA_datetime_get_all (
IN ora_datetime dt,
OUT short *year, /* gregorian year; range is -4712 <= year <= 9999 */
OUT ORADBI_DTMonth *month, /* month; range is 1 <= month < 12 */
OUT byte *day, /* day; range is 1 <= day <= 31 */
OUT byte *hours, /* hours; range is 0 <= hours <=23 */
OUT byte *minutes, /* minutes; range is 0 <= minutes <= 59 */
OUT byte *seconds /* seconds; range is 0 <= seconds <= 59 */
);

lresult ORADB_CALL ORA_datetime_set_fld (
IN ora_datetime dt,
IN ORADBI_DTField dt_field,
IN short dt_val,
OUT ora_error_t *error /* NULL for no err msg return */
);

short ORADB_CALL ORA_datetime_get_fld (
IN ora_datetime dt,
IN ORADBI_DTField dt_field
);

lresult ORADB_CALL ORA_string_to_datetime (
IN const char *dt_string, /* datetime string such as: 1975-08-14 12:53:42 */
IN char *dt_format, /* datetime format such as: yyyy-mm-dd hh:uu:ss */
OUT ora_datetime dt_to, /* datetime that string translated to */
OUT ora_error_t *error /* NULL for no err msg return */
);

lresult ORADB_CALL ORA_datetime_to_string (
IN ora_datetime dt_in, /* datetime to be translated */
IN char *dt_format, /* datetime format such as: yyyy-mm-dd hh:uu:ss */
OUT char *string_to, /* datetime string such as: 1975-08-14 12:53:42 */
OUT ora_error_t *error /* NULL for no err msg return */
);

/* frees a ora_datetime */
void ORADB_CALL ORA_datetime_free (
IN ora_datetime dt
);

#ifdef __cplusplus
}
#endif

/*====================================================================*/
#endif /* ndef ORADBI_H_INCLUDED . cheungmine@gmail.com */
您可以在下面的链接中下载整个工程(包含测试一个项目)，用VS2005（VC8）打开、编译。如果有任何问题，可以留言或发e-mail给我。

http://download.csdn.net/source/399444