oracle pro c - Pro *C query IN 子句中的多个动态值

Question

我想读取一个平面文件来获取一个动态的值列表（值的数量不是固定的），然后我想在Pro *C中选择查询的IN子句中使用此值列表。使用Pro * C实现这一目标的最佳方法是什么？我在这里和这里遇到了一些有用的文章，但我只是想检查是否有更适合我的用例的解决方案。权衡我可能拥有的选项的利弊也很有用。

举个例子，下面是查询：

SELECT ca.co_id
INTO :host_co_id_1
FROM contr1 ch1, contr2 ca
WHERE ch_seqno = (SELECT MAX (ch_seqno) FROM ontr1 ch2
WHERE ch1.co_id = ch2.co_id)
and ch1.ch_status IN ('a','s')
AND ca.co_id = ch1.co_id
AND ca.tmcode IN (14,16,36,37,38,39,40,41,42,79,60);

号码列表：

14,16,36,37,38,39,40,41,42,79,60

是从文件中读取的动态列表。

Answer 1

这可以使用 Oracle Dynamic SQL：Method 4 来实现。 演示中包含的sample10.pc说明了此方法。
下面的示例代码
变量stmt可以从具有具有多个动态值的 IN 子句的文件中读取。

 /*
* A very simple program that demonstrates how to do
* array fetches using dynamic SQL Method 4.
* file name: sample.pc
* environment: Win 7,code::blocks(mingw/gcc),oracle 11g(on solaris)
* Make sure to precompile with MODE=ORACLE.
example:
C:oracle_instant_clientinstantclient_11_2sdkproc.exe DYNAMIC=ORACLE C:codesample.pc
*/
#include <stdio.h> 
#include <stdlib.h>
#include <oci.h>
EXEC SQL INCLUDE sqlcpr;
EXEC SQL INCLUDE sqlda;
EXEC SQL INCLUDE oraca;
EXEC SQL INCLUDE sqlca;
#define MAX_SELECT_ITEMS   15
#define FETCH_SIZE         100  /* Fetch in 100 row chunks. */
#define MAX_CHARS          20   /* Change this for max colume size */
#define MAX_NAME_SIZE      20  /* Maximum size of a select-list item name. */
SQLDA   *selda; 
/* Data buffer. */
char c_data[MAX_SELECT_ITEMS][FETCH_SIZE][MAX_CHARS];
void print_rows(n)
int n;
{
int row, sli;
for (row = 0; row < n; row++)
{
    for (sli = 0; sli < selda->N; sli++)
    {
        printf("%.20s ", c_data[sli][row]);
    }
   printf("n");
}
}
EXEC SQL BEGIN DECLARE SECTION;
int array_size = FETCH_SIZE;  /* needs to be a host var for FOR */
char *username = "ORACLE_USER/ORACLE_PASS";
char sid[]="ORACLE_SID";
char *stmt = "select t.a,t.b,t.c,p.d,t.e,t.f,t.g,t.h,t.i,t.j from table_t t,table_p p where p.error_code = t.error_code and rownum <= 50";
EXEC SQL END DECLARE SECTION;

void sql_error()
{
char msgbuf[512];/*
size_t msgbuf_len, msg_len;
msgbuf_len = sizeof(msgbuf);
sqlglm(msgbuf, &msgbuf_len, &msg_len);
printf ("nn%.*sn", msg_len, msgbuf);*/
EXEC SQL WHENEVER SQLERROR CONTINUE;
EXEC SQL ROLLBACK WORK RELEASE;
exit(EXIT_FAILURE);
}
void main() 
{ 
int row_count;
int sli;     /* select-list item */
EXEC SQL CONNECT :username USING :sid; 
if (sqlca.sqlcode == 0)
printf("Connected.n"); 
else
{
printf("Connection failed.n");
exit(EXIT_FAILURE);
}
EXEC SQL WHENEVER SQLERROR DO sql_error();

selda = SQLSQLDAAlloc (SQL_SINGLE_RCTX, MAX_SELECT_ITEMS, MAX_NAME_SIZE, 0);
EXEC SQL PREPARE S FROM :stmt;
EXEC SQL DECLARE C CURSOR FOR S;
EXEC SQL OPEN C;
EXEC SQL DESCRIBE SELECT LIST FOR S INTO selda;
selda->N = selda->F;   /* Assumed not negative. */
for (sli = 0; sli < selda->N; sli++)
{
    /* Set addresses of heads of the arrays in the V element. */
    selda->V[sli] = c_data[sli][0];
    /* Convert everything to varchar on output. */
    selda->T[sli] = 1;
    /* Set the maximum lengths. */
    selda->L[sli] = MAX_CHARS;
}
for (row_count = 0; ;)
{
    /* Do the fetch. The loop breaks on NOT FOUND. */
    EXEC SQL FOR :array_size FETCH C USING DESCRIPTOR selda;
    print_rows(sqlca.sqlerrd[2] - row_count);
    row_count = sqlca.sqlerrd[2];
    if (sqlca.sqlcode == 1403)
    break;
}
/*    if (sqlca.sqlerrd[2] - row_count > 0)
print_rows(sqlca.sqlerrd[2] - row_count); */
printf("n%d rows retrievedn", sqlca.sqlerrd[2]);
EXEC SQL ROLLBACK RELEASE;
exit(EXIT_SUCCESS);
}