如何使用DB_Library

[zhangzhiqiang]

有谁知道如何在C语言调用DB_Library时，
取得Numeric型字段的值。
如11111111，45
谢谢。

[929]

我想关键是找对应的数据类型：
NUMERIC对应的数据类型为：
vartype varaddr SQL Server type of column
NUMERICBIND DBNUMERIC SQLNUMERIC
其中VARTYPE是指DBBIND中连接的类型，VARADDR是指在DB编程中所能用到的变量类型，而SQL SERVER TYPE OF COLUMN指的是SQL SERVER中的数据类型。找好对应的类型就容易取数了。
应用DB_Library，可用这两个函数之一来取得字段值。
RETCODE dbbind (
PDBPROCESS dbproc,
INT column,
INT vartype,
DBINT varlen,
LPBYTE varaddr );


有一例子：
DBNUMERIC xvariable;
DBCHAR yvariable[10];

// Read the query into the command buffer.
dbcmd(dbproc, "select x = 100, y = 'hello'");
// Send the query to SQL Server.
dbsqlexec(dbproc);
// Get ready to process the results of the query.
dbresults(dbproc);
//这两步很重要，在进行BIND前，要指明NUMERIC型变量的精度信息。可用DEFAULTPRECISION和DEFAULTSCALE设置。

xvariable.precision=DEFAULTPRECISION

xvariable.scale=DEFAULTSCALE


// Bind column data to program variables.
dbbind(dbproc, 1, NUMERICBIND, (DBINT) 0, (BYTE *) &xvariable);
dbbind(dbproc, 2, STRINGBIND, (DBINT) 0, yvariable);

// Now process each row.
while (dbnextrow(dbproc) != NO_MORE_ROWS)
{
// C-code to print or process row data
}
....

还有一函数稍微麻烦：
LPCBYTE dbdata (
PDBPROCESS dproc,
INT column );


DBPROCESS *dbproc;
DBINT row_number = 0;
DBINT object_id;

// Put the command into the command buffer.
dbcmd(dbproc, "select id from sysobjects");

// Send the command to SQL Server and begin execution.
dbsqlexec(dbproc);

// Process the command results.
dbresults(dbproc);
// Examine the data in each row.
while (dbnextrow(dbproc) != NO_MORE_ROWS)
{
row_number+;
object_id = *((DBINT *)dbdata(dbproc, 1));
printf("row %ld, object id is %ld.\n", row_number, object_id);
}
此例子以整形数据为例，改变数据类型，访问NUMERIC列即可。
以上介绍均可由SQL SERVER BOOK ONLINE获得。

[coolstar]

给分呀

[taosi]

gz

[wujp1976]

我的源码：



int f_get_memberbasicinfo(char *gs_membercode,MEMBERINFO *meminfo) //取得会员基本信息
{
int ret,retcode = RET_NO ;

dbcmd(dbproc," select cMemberNo,vcMemberName,cMemberClass, " );
dbcmd(dbproc," cGenderNo,cNationNo,cDegreeNo,vcIdentity, " );
dbcmd(dbproc," vcAddr,vcZip,vcPhone, " );
dbcmd(dbproc," vcCompany,mDTCAmt,mMTCAmt,mYTCAmt,mTCAmt,mMarkAmt");
dbcmd(dbproc," from soMemberCardVw " );
dbfcmd(dbproc," where cMemberNo = '%s' ",gs_membercode );

if(dbsqlexec(dbproc) == FAIL){
f_messagebox("数据库错误(cMemberNo)",1);
return RET_ERROR;
}

while((ret = dbresults(dbproc)) != NO_MORE_RESULTS )
{
if(ret == SUCCEED) {
dbbind(dbproc,1,STRINGBIND, (DBCHAR) 0,meminfo->cMemberNo );
dbbind(dbproc,2,STRINGBIND, (DBCHAR) 0,meminfo->vcMemberName);
dbbind(dbproc,3,STRINGBIND, (DBCHAR) 0,meminfo->cMemberClass);
dbbind(dbproc,4,STRINGBIND, (DBCHAR) 0,meminfo->cGenderNo );
dbbind(dbproc,5,STRINGBIND, (DBCHAR) 0,meminfo->cNationNo );
dbbind(dbproc,6,STRINGBIND, (DBCHAR) 0,meminfo->cDegreeNo );
dbbind(dbproc,7,STRINGBIND, (DBCHAR) 0,meminfo->vcIdentity );
dbbind(dbproc,8,STRINGBIND, (DBCHAR) 0,meminfo->vcAddr );
dbbind(dbproc,9,STRINGBIND, (DBCHAR) 0,meminfo->vcZip );
dbbind(dbproc,10,STRINGBIND, (DBCHAR) 0,meminfo->vcPhone );
dbbind(dbproc,11,STRINGBIND, (DBCHAR) 0,meminfo->vcCompany );
dbbind(dbproc,12,FLT8BIND, (DBCHAR) 0,&meminfo->mDTCAmt );
dbbind(dbproc,13,FLT8BIND, (DBCHAR) 0,&meminfo->mMTCAmt );
dbbind(dbproc,14,FLT8BIND, (DBCHAR) 0,&meminfo->mYTCAmt );
dbbind(dbproc,15,FLT8BIND, (DBCHAR) 0,&meminfo->mTCAmt );
dbbind(dbproc,16,FLT8BIND, (DBCHAR) 0,&meminfo->mMarkAmt );

while(dbnextrow(dbproc) != NO_MORE_ROWS){
meminfo->cMemberNo[14] = 0 ;
meminfo->vcMemberName[16] = 0;
meminfo->cMemberClass[1] = 0 ;
meminfo->cGenderNo[1] = 0 ;
meminfo->cNationNo[3] = 0 ;
meminfo->cDegreeNo[3] = 0 ;
meminfo->vcIdentity[40] = 0 ;
meminfo->vcAddr[60] = 0 ;
meminfo->vcZip[6] = 0 ;
meminfo->vcPhone[40] = 0 ;
meminfo->vcCompany[40] = 0 ;
retcode = RET_OK;
}/* while(dbnextrow(dbproc) */
}/* if */
}/*while*/

return retcode;
}/* f_getmemberbasicinfo */