pro*C访问DB2数据库的例子

test.sqc

$ cat test.sqc
#include <stdio.h>
#include <sqlenv.h>

EXEC SQL INCLUDE SQLCA ;

EXEC SQL BEGIN DECLARE SECTION ;
    char   hvalue[16];
EXEC SQL END DECLARE SECTION ;


char sqlcamsg[1025];

#define DUMP_SQLCA()                                                    \
  {                                                                     \
    printf("******************  DUMP OF SQLCA  ******************\n");  \
    printf("SQLCAID: %s\n",     sqlca.sqlcaid);                         \
    printf("SQLCABC: %d\n",     sqlca.sqlcabc);                         \
    printf("SQLCODE: %d\n",     sqlca.sqlcode);                         \
    printf("SQLERRML: %d\n",    sqlca.sqlerrml);                        \
    printf("SQLERRMC: %s\n",    sqlca.sqlerrmc);                        \
    printf("SQLERRP: %s\n",     sqlca.sqlerrp);                         \
    printf("SQLERRD[0]: %d\n",  sqlca.sqlerrd[0]);                      \
    printf("SQLERRD[1]: %d\n",  sqlca.sqlerrd[1]);                      \
    printf("SQLERRD[2]: %d\n",  sqlca.sqlerrd[2]);                      \
    printf("SQLERRD[3]: %d\n",  sqlca.sqlerrd[3]);                      \
    printf("SQLERRD[4]: %d\n",  sqlca.sqlerrd[4]);                      \
    printf("SQLERRD[5]: %d\n",  sqlca.sqlerrd[5]);                      \
    printf("SQLWARN: %s\n",     sqlca.sqlwarn);                         \
    printf("SQLSTATE: %s\n",    sqlca.sqlstate);                        \
    printf("*****************   END OF SQLCA DUMP  **************\n");  \
  }

#define CHECK_SQL(failure_string)               \
  {                                             \
    if (sqlca.sqlcode != 0) {                   \
      printf("!!!ERROR: %s\n", failure_string); \
      sqlaintp(sqlcamsg, 1024, 0, &sqlca);      \
      printf("%s\n", sqlcamsg);                 \
      DUMP_SQLCA();                             \
      goto done;                                \
    }                                           \
  }


main (int argc, char *argv[])
{
    EXEC SQL CONNECT TO <DBNAME> USER <USER> USING <PASSWD>;
    CHECK_SQL("Connect failed");

    EXEC SQL SELECT 'ABCD' into :hvalue FROM SYSIBM.SYSDUMMY1;
    CHECK_SQL("Select failed");

    printf("Select Result: [%s]\n", hvalue);

done:
    EXEC SQL CONNECT RESET;
}

makefile

$ cat makefile 

TARGET=test
DB2DIR?=~/sqllib

$(TARGET): $(TARGET).sqc
        db2 connect to <DBNAME> user <USER> using <PASSWD>
        db2 prep $(TARGET).sqc bindfile 
        db2 bind $(TARGET).bnd 
        #db2 list packages 
        #db2 drop package package-name 
        gcc -o $(TARGET) -I$(DB2DIR)/include $(TARGET).c -L$(DB2DIR)/lib64 -ldb2

clean:
        rm -f $(TARGET) $(TARGET).bnd $(TARGET).c

run

$ make
db2 connect to <DBNAME> user <USER> using <PASSWD>

   Database Connection Information

 Database server        = <DB SERVER>
 SQL authorization ID   = <USER>
 Local database alias   = <DBNAME>

db2 prep test.sqc bindfile 

LINE    MESSAGES FOR test.sqc
------  --------------------------------------------------------------------
        SQL0060W  The "C" precompiler is in progress.
        SQL0091W  Precompilation or binding was ended with "0" 
                  errors and "0" warnings.
db2 bind test.bnd 

LINE    MESSAGES FOR test.bnd
------  --------------------------------------------------------------------
        SQL0061W  The binder is in progress.
        SQL0091N  Binding was ended with "0" errors and "0" warnings.
#db2 list packages 
#db2 drop package package-name 
gcc -o test -I${DB2DIR}/include test.c -L${DB2DIR}/lib64 -ldb2
$
$ ./test 
Select Result: [ABCD]