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The following modified source file is the result of preprocessing
program cex2 (shown at the end of Chapter 1). In the listing, the
parts of the code are shaded for easy reference, as follows: Conditional compiler directives that tell the compiler to ignore the original SQL commands. Begin and end braces that indicate the preprocessor-generated code.
Figure 2-6 Sample Modified Source File
#include "cex2.sqlt"\
#include "cex2.sqlv"\
#include "cex2.sqle"
/* Program cex2 */
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/* This program illustrates the use of SQL's SELECT command to */
/* retrieve one row or tuple of data at a time. */
/* BEGIN WORK is executed before the SELECT and a COMMIT WORK */
/* is executed after the SELECT. An indicator variable is also */
/* used for SalesPrice. */
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
typedef int boolean;
char response[2];
boolean Abort;
#include <stdio.h>
#define OK 0
#define NotFound 100
#define MultipleRows -10002
#define DeadLock -14024
#define FALSE 0
#define TRUE 1
#if 0
EXEC SQL INCLUDE SQLCA;
#endif
sqlca_type sqlca;
/* SQL Communication Area */
/* Begin Host Variable Declarations */
#if 0
EXEC SQL BEGIN DECLARE SECTION;
#endif
char PartNumber[17];
char PartName[31];
double SalesPrice;
sqlind SalesPriceInd;
char SQLMessage[133];
#if 0
EXEC SQL END DECLARE SECTION;
#endif
/* End Host Variable Declarations */
int SQLStatusCheck() /* Function to Display Error Messages */
{
Abort = FALSE;
if (sqlca.sqlcode < DeadLock)
Abort = TRUE;
do {
#if 0
EXEC SQL SQLEXPLAIN :SQLMessage;
#endif
{
sqlxplnc(&sqlca,&sqltempv,133,1);
sqltempv.rec1.
SQLREC1_FIELD1[sqltempv.rec1.SQLREC1_FIELD1_LEN] = '\0';
strcpy(SQLMessage,
sqltempv.rec1.SQLREC1_FIELD1);
}
printf("\n");
printf("%s\n",SQLMessage);
} while (sqlca.sqlcode != 0);
if (Abort)
{
EndTransaction();
ReleaseDBE();
}
} /* End SQLStatusCheck Function */
boolean ConnectDBE() /* Function to Connect to ../sampledb/PartsDBE */
{
boolean ConnectDBE;
ConnectDBE = TRUE;
printf("\n Connect to ../sampledb/PartsDBE");
#if 0
EXEC SQL CONNECT TO '../sampledb/PartsDBE';
#endif
{
sqlvar1 = "00AE00002E2E2F73616D706C6564622F5061727473444245
202020202020202020202020202020202020202020202020202020202020
202020202020202020202020202020202020202020202020202020202020
202020202020202020202020202020202020202020202020202020202020
202020202020202020202020202020202020";
sqlxconc(&sqlca,sqlvar1);
}
if (sqlca.sqlcode != OK)
{
ConnectDBE = FALSE;
SQLStatusCheck();
} /* End if */
return (ConnectDBE);
} /* End of ConnectDBE Function */
int ReleaseDBE() /* Function to Release ../sampledb/PartsDBE */
{
printf("\n");
printf("\n Release ../sampledb/PartsDBE");
printf("\n");
#if 0
EXEC SQL RELEASE;
#endif
{
sqlvar2 = "00B200002020202020202020202020202020202020202020FFFFFFFF";
sqlxconc(&sqlca,sqlvar2);
}
if (sqlca.sqlcode != OK) SQLStatusCheck();
} /* End ReleaseDBE Function */
boolean BeginTransaction() /* Function to Begin Work */
{
boolean BeginTransaction;
BeginTransaction = TRUE;
printf("\n");
printf("\n Begin Work");
#if 0
EXEC SQL BEGIN WORK;
#endif
{
sqlvar3 = "00A6007F00110061";
sqlxconc(&sqlca,sqlvar3);
}
if (sqlca.sqlcode != OK)
{
BeginTransaction = FALSE;
SQLStatusCheck();
ReleaseDBE();
} /* End if */
return (BeginTransaction);
} /* End BeginTransaction Function */
int EndTransaction() /* Function to Commit Work */
{
printf("\n");
printf("\n Commit Work");
#if 0
EXEC SQL COMMIT WORK;
#endif
{
sqlvar4 = "00A10000";
sqlxconc(&sqlca,sqlvar4);
}
if (sqlca.sqlcode != OK) SQLStatusCheck();
} /* End EndTransaction Function */
int DisplayRow() /* Function to Display Parts Table Rows */
{
printf("\n");
printf("\n Part Number: %s\n", PartNumber);
printf(" Part Name: %s\n", PartName);
if (SalesPriceInd < 0) {
printf(" Sales Price: is NULL \n");
}
else
printf(" Sales Price: %10.2f\n", SalesPrice);
} /* End of DisplayRow */
int Select() /* Function to Query Parts Table */
{
do {
printf("\n");
printf("\n Enter Part Number within Parts Table or '/' to STOP > ");
scanf("%s",PartNumber);
if (PartNumber[0] != '/') {
BeginTransaction();
printf("\n SELECT PartNumber, PartName, SalesPrice");
#if 0
EXEC SQL SELECT PartNumber, PartName, SalesPrice
INTO :PartNumber,
:PartName,
:SalesPrice :SalesPriceInd
FROM PurchDB.Parts
WHERE PartNumber = :PartNumber;
#endif
{
sqltempv.rec2.SQLREC2_FIELD1_LEN =
strlen(PartNumber);
strcpy(sqltempv.rec2.SQLREC2_FIELD1,
PartNumber);
sqlxfetc(&sqlca,sqlowner,sqlmodname,1,&sqltempv,24,80,1);
if (sqlca.sqlcode == 0)
{
sqltempv.rec3.
SQLREC3_FIELD1[sqltempv.rec3.SQLREC3_FIELD1_LEN] = '\0';
strcpy(PartNumber,
sqltempv.rec3.SQLREC3_FIELD1);
sqltempv.rec3.
SQLREC3_FIELD2[sqltempv.rec3.SQLREC3_FIELD2_LEN] = '\0';
strcpy(PartName,
sqltempv.rec3.SQLREC3_FIELD2);
SalesPriceInd =
sqltempv.rec3.SQLREC3_FIELD3_IND;
if (sqltempv.rec3.SQLREC3_FIELD3_IND >= 0)
{
SalesPrice =
sqltempv.rec3.SQLREC3_FIELD3;
}
}
else
{
}
}
if ((sqlca.sqlwarn[0] == 'W') || (sqlca.sqlwarn[0] == 'w')) {
printf("\n SQL WARNING has occurred. The following row");
printf("\n of data may not be valid!");
}
if (sqlca.sqlcode == OK) {
DisplayRow();
}
else if (sqlca.sqlcode == NotFound) {
printf("\n Row not found!");
}
else if (sqlca.sqlcode == MultipleRows) {
printf("\n WARNING: More than one row qualifies!");
}
else {
SQLStatusCheck();
}
EndTransaction();
}
} /* End do */
while (PartNumber[0] != '/');
}/* End of Select Function */
main() /* Beginning of program */
{
printf("\n Program to SELECT specified rows from");
printf("\n the Parts Table - cex2");
printf("\n");
printf("\n Event List:");
printf("\n CONNECT TO ../sampledb/PartsDBE");
printf("\n BEGIN WORK");
printf("\n SELECT the specified row from the Parts Table");
printf("\n until the user enters a '/'");
printf("\n COMMIT WORK");
printf("\n RELEASE from ../sampledb/PartsDBE");
printf("\n");
if (ConnectDBE()) {
Select();
ReleaseDBE();
}
else
printf("\n Error: Cannot Connect to ../sampledb/PartsDBE!\n");
} /* End of Program */
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