我想检查我的存储过程，如果我的RawMaterialStock表列RawMaterial Id等于我的过程参数@RawMaterialId
我这样做。
if(dbo.[RawMaterialStock].RawMaterialId=@RawMaterialId)
BEGIN
Update [RawMaterialStock]
set
Quantity=Quantity+ @TotalQty
end
ELSE
BEGIN
INSERT INTO [dbo].[RawMaterialStock]
([RawMaterialId],Quantity)
VALUES
(@RawMaterialId,@TotalQty)
end
但它给出错误Multipair Identifier无法绑定。 我如何检查这种情况，我是初学者程序员请简单解释一下。
答案 0 :(得分：1)
使用合并。 像这样：
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
typedef struct{
char *subjName;
char *lectName;
char *lectSurname;
int credits;
int num_students;
}Subject;
typedef struct{
Subject **subjs;
int num_subjs;
}Subjects;
int numOfSubjs=0;
void listInput();
void listEdit();
void listDelete();
void listPrint();
int userChoice(int select);
int enterNumber(char *name);
void saveToFile(Subjects *subjects);
void readFromFile(Subjects *subjects);
int main() {
Subjects *subjects = malloc(sizeof(Subjects));
subjects->num_subjs = 0;
subjects->subjs = NULL;
readFromFile(subjects);
int r=1;
while(r!=0){
int select=userChoice(select);
switch(select){
case 1:
listPrint(subjects);
break;
case 2:
listInput(&subjects);
break;
case 3:
listDelete(subjects);
break;
case 4:
listEdit(subjects);
break;
case 0:
r=0;
break;
}
}
saveToFile(subjects);
return 0;
}
int userChoice(int select){ // menu options
int choice,input=0;
printf("(1). View all the data\n");
printf("(2). Enter new data\n");
printf("(3). Delete data\n");
printf("(4). Edit data\n");
printf("(0). Exit\n");
printf("-----------------------------\n");
while(input!=1){
choice = enterNumber("menu");
if(choice>4 || choice<0){
printf("Invalid input \n");
}
else
input = 1;
}
return choice;
}
void listPrint(Subjects *subjects){ // print data
int i;
for(i=0; i< numOfSubjs; i++){
printf("%d, %s, %s, %s, %d, %d\n",i+1, subjects->subjs[i]->subjName, subjects->subjs[i]->lectName, subjects->subjs[i]->lectSurname, subjects->subjs[i]->credits, subjects->subjs[i]->num_students);
}
printf("Number of entries: %d \n", numOfSubjs);
}
char *getln() //dynamically allocate input string
{
char *line = NULL, *tmp = NULL;
size_t size = 0, index = 0;
int ch = 1;
while (ch) {
ch = getc(stdin);
if (ch == '\n')
ch = 0;
if (size <= index) {
size += 1;
tmp = realloc(line, size);
if (!tmp) {
free(line);
line = NULL;
break;
}
line = tmp;
}
line[index++] = ch;
}
return line;
}
void saveToFile(Subjects *subjects){
FILE *data;
data = fopen("data.bin","wb");
printf("%s", subjects->subjs[0]);
for(int i=0; i<numOfSubjs; i++){
fwrite(&subjects->subjs[i],sizeof(Subject*),1,data);
}
fclose(data);
}
void readFromFile(Subjects *subjects){
FILE *data;
int i=0;
data = fopen("data.bin","rb");
while(!feof(data))
{
fread(&subjects->subjs[i],sizeof(Subject*),1,data);
i++;
}
fclose(data);
}
int isText(char *str,char *name){ // check if is text
for(int i = 0; i < strlen(str);i++){
if((str[i]<'A' || str[i]>'z') && str[i]!=' '){
printf("Error, %s must be a text \n",name);
return 0;
}
}
return 1;
}
int enterNumber(char *name){ // enter number and check if is number
int input=0, crash=0, num=0;
while(input!=1)
{
crash=0;
printf("Enter the number of %s\n", name);
scanf("%d", &num);
while(getchar()!='\n')
{
crash++;
}
if(crash>0 || num<0)
printf("Error, enter a not negative number of %s\n", name);
else if(crash==0)
input=1;
}
return num;
}
void listInput(Subjects **p_subjects){ // input new data
Subject *new_subj = malloc(sizeof(Subject));
new_subj->subjName = NULL;
new_subj->lectName = NULL;
new_subj->lectSurname = NULL;
new_subj->credits = 0;
new_subj->num_students = 0;
do{
printf("Enter the name of the subject \n");
new_subj->subjName = getln();
}while(!isText(new_subj->subjName,"Subject name"));
do{
printf("Enter the name of the lecturer \n");
new_subj->lectName = getln();
new_subj->lectName[0] &= '_';
}while(!isText(new_subj->lectName,"Lecturer's name"));
do{
printf("Enter the surname of the lecturer\n");
new_subj->lectSurname = getln();
new_subj->lectSurname[0] &= '_'; //Convert to uppercase if lowercase
}while(!isText(new_subj->lectSurname,"Lecturer's name"));
new_subj->credits = enterNumber("credits");
new_subj->num_students = enterNumber("students");
(*p_subjects)->subjs = realloc((*p_subjects)->subjs,sizeof(Subject*)*(++(*p_subjects)->num_subjs));
(*p_subjects)->subjs[(*p_subjects)->num_subjs-1] = new_subj;
numOfSubjs++;
printf("Added a new entry.\n\n");
}
void listDelete(Subjects *subjects){ // delete entries
int del;
if(numOfSubjs==0)
printf("Number of entries is 0, can't delete anything\n");
else{
printf("Enter 0 to exit. Number of subjects : %d \n", numOfSubjs);
while(1){
del = enterNumber("entry which you would like to delete");
if(del<=numOfSubjs && del>0){
for(int i = del-1; i<numOfSubjs-1; i++){
subjects->subjs[i]=subjects->subjs[i+1];
subjects->subjs = realloc(subjects->subjs,sizeof(Subject*)*(--subjects->num_subjs));
}
numOfSubjs--;
break;
}
if(del>numOfSubjs)
printf("Error, input a number between 1 and %d (or enter 0 to exit)\n", numOfSubjs);
else
break;
}
}
}
void listEdit(Subjects *subjects){ // edit entries
int choice=0, editEntry=0, editSubj=0;
if(numOfSubjs == 0)
printf("Number of entries is 0, can't edit anthing\n");
else{
while(1){
printf("Number of entry must be between 1 and %d \n", numOfSubjs);
choice = enterNumber("entry you would like to edit.");
if(choice>0 && choice<=numOfSubjs){
while(1){
editEntry = enterNumber("what would you like to edit\n 1 - Subject name\n 2 - Lecturer's name\n 3 - Lecturer's surname\n 4 - Number of credits\n 5 - Number of students");
if(editEntry>0 && editEntry <=5){
switch(editEntry){
case 1:
do{
printf("Enter the name of the subject \n");
subjects->subjs[choice-1]->subjName = getln();
}while(!isText(subjects->subjs[choice-1]->subjName,"Subject name"));
break;
case 2:
do{
printf("Enter Lecturer's name \n");
subjects->subjs[choice-1]->lectName = getln();
}while(!isText(subjects->subjs[choice-1]->lectName,"Lecturer's name"));
break;
case 3:
do{
printf("Enter Lecturer's surname \n");
subjects->subjs[choice-1]->lectSurname = getln();
}while(!isText(subjects->subjs[choice-1]->lectSurname,"Lecturer's surname"));
break;
case 4:
subjects->subjs[choice-1]->credits = enterNumber("credits");
break;
case 5:
subjects->subjs[choice-1]->num_students = enterNumber("students");
break;
}
}
break;
}
}
break;
}
}
}
答案 1 :(得分：0)
你真的不能这样做：
if(dbo.[RawMaterialStock].RawMaterialId=@RawMaterialId)
BEGIN
--Stuff
END
相反，您必须将表中的数据选择为自己的变量。
DECLARE @Tmp int
SELECT @Tmp = dbo.[RawMaterialStock].RawMaterialId
IF (@Tmp = @RawMaterialId)
BEGIN
--Stuff
END
或做一些聪明的事情，比如
IF EXISTS (SELECT 0 FROM dbo.[RawMaterialStock] WHERE RawMaterialId = @RawMaterialId)
BEGIN
--Stuff
END