dbms.rar_c语言 数据库_c语言DBMS_dbms_数据库管理

/* dbms2.cpp : Database Manage System (2) -- Add & View Record. */ #include <stdio.h> #include <stdlib.h> #include <conio.h> #include <string.h> #define MAX_SIZE 50 /*表中所含字段最大长度*/ #define FILE_NAME_LENGTH 15 /*文件名最大长度*/ #define FIELD_NAME_LENGTH 15 /*字段名最大长度*/ typedef struct { char sFieldName[FIELD_NAME_LENGTH]; char sType[8]; int iSize; char bKey; char bNullFlag; char bValidFlag; } TableMode,*PTableMode; void main() { FILE *fp,*tempfp; int tempi,tempi1,tempiNum,iNum,jNum; /*iNum is the number of the Field,and jNum is Record */ char tempc,temps[FILE_NAME_LENGTH],*temps1; char recordset[2*MAX_SIZE][FILE_NAME_LENGTH]; TableMode FieldSet[MAX_SIZE]; char dbf[FILE_NAME_LENGTH],datf[FILE_NAME_LENGTH],tname[FILE_NAME_LENGTH],temptn[FILE_NAME_LENGTH]; int bFound; /*found the table */ printf("\n*********** Database Manage System Design (2)- Add & View Record ************ "); printf("\n *********** ECUST by LZH ************ "); while(1){ printf("\n"); printf("\n"); printf("\n"); printf("\n ********************************* "); printf("\n"); printf("\n 0 -Add New Record"); printf("\n 1 -View Records"); printf("\n 2 -Exit"); printf("\n"); printf("\n ********************************* "); printf("\nEnter your choice: "); tempc=getch(); while(tempc!='0'&&tempc!='1'&&tempc!='2')tempc=getch(); printf("%c",tempc); switch(tempc){ case '0': printf("\n\n******** Add New Record ********"); printf("\ninput Data file (.dat) to Save New Record (MAX char[15]): "); scanf("%15s",datf); printf("\ninput the Database File Name(.dbf) which the Table Mode is in : "); scanf("%15s",dbf); if((fp=fopen(dbf,"rb")) == NULL ){ printf("\nFile Not Exist or Bad File!\n" ); break; } printf("\ninput the Table Name which the Table Mode is in : "); scanf("%15s",temptn); /* find Table Mode in .dbf*/ while(!feof(fp)){ bFound=0; tempi=fread(&tempc,sizeof(char),1,fp); if(!tempi)break; fread(tname,sizeof(char),FILE_NAME_LENGTH,fp); fread(&iNum,sizeof(int),1,fp); fread(FieldSet,sizeof(TableMode),iNum,fp); if(strcmp(tname,temptn)==0){ printf("\nFound! Table Fields are as following:"); printf("\nFieldName\tType\tSize\tKey\tNull"); for(tempi=0;tempi<iNum;tempi++) printf("\n%s\t%s\t%d\t%c\t%c",FieldSet[tempi].sFieldName,FieldSet[tempi].sType, FieldSet[tempi].iSize,FieldSet[tempi].bKey,FieldSet[tempi].bNullFlag); bFound=1; break; /*break while*/ } } fclose(fp); if(!bFound){ printf("\nNo such a table in %s",dbf); break; } if((fp=fopen(datf,"ab+")) == NULL ){ printf("\nCan't Creat Data File %s!",datf); break; } jNum=0; printf("\n\nAdd New Record according to below Table Mode."); do{ for(tempi=0;tempi<iNum;tempi++){ printf("\ninput %s: ",FieldSet[tempi].sFieldName); scanf("%15s",temps); strcpy(&recordset[jNum*iNum+tempi][0],temps); } jNum++; printf("\nAdded A New Record Successfully!"); printf("\nContinue Add Another Record? (y -Yes, n -No): "); tempc=getch(); while(tempc!='y'&&tempc!='n')tempc=getch(); printf("%c",tempc); }while(tempc=='y'); temps1=(char*)malloc(sizeof(char)*jNum); for(tempi=0;tempi<jNum;tempi++)temps1[tempi]='V'; /* V means validation */ /* write .dat */ fwrite("~",sizeof(char),1,fp); fwrite(tname,sizeof(char),FILE_NAME_LENGTH,fp); fwrite(&jNum,sizeof(int),1,fp); fwrite(&iNum,sizeof(int),1,fp); fwrite(temps1,sizeof(char),jNum,fp); fwrite(recordset,sizeof(char),FILE_NAME_LENGTH*sizeof(char)*jNum*iNum,fp); fclose(fp); free(temps1); break; case '1': printf("\n\n******** View Records ********"); printf("\ninput Database File Name(.dbf) : "); scanf("%15s",dbf); if((tempfp=fopen(dbf,"rb")) == NULL ){ printf("\nFile Not Exist or Bad File!\n" ); break; } printf("\ninput Data File Name(.dat) : "); scanf("%15s",datf); if((fp=fopen(datf,"rb"))== NULL ){ printf("\nFile Not Exist or Bad File!\n" ); break; } printf("\nTables in %s are as following:",datf); while(!feof(fp)){ tempi=fread(&tempc,sizeof(char),1,fp); if(!tempi)break; if(tempc!='~'){ printf("\n%s Data Format NOT corroct!",datf); exit(1); } fread(tname,sizeof(char),FILE_NAME_LENGTH,fp); printf("\n%s",tname); fread(&jNum,sizeof(int),1,fp); fread(&iNum,sizeof(int),1,fp); temps1=(char*)malloc(sizeof(char)*jNum); fread(temps1,sizeof(char),jNum,fp); fread(recordset,sizeof(char),FILE_NAME_LENGTH*jNum*iNum,fp); free(temps1); } printf("\n"); printf("\ninput Table Name to view it's Records: "); scanf("%15s",temptn); /*find table fields in .dbf*/ while(!feof(tempfp)){ bFound=0; tempi=fread(&tempc,sizeof(char),1,tempfp); if(!tempi)break; fread(tname,sizeof(char),FILE_NAME_LENGTH,tempfp); fread(&tempiNum,sizeof(int),1,tempfp); fread(FieldSet,sizeof(TableMode),tempiNum,tempfp); if(strcmp(tname,temptn)==0){ bFound=1; break; /*break while*/ } } fclose(tempfp); if(!bFound){ printf("\nNo such a table in %s",dbf); break; } /* end find */ rewind(fp); bFound=0; while(!feof(fp)){ tempi=fread(&tempc,sizeof(char),1,fp); if(!tempi)break; fread(tname,sizeof(char),FILE_NAME_LENGTH,fp); fread(&jNum,sizeof(int),1,fp); fread(&iNum,sizeof(int),1,fp); temps1=(char*)malloc(sizeof(char)*jNum); fread(temps1,sizeof(char),jNum,fp); if(strcmp(tname,temptn)==0){ printf("\nTable Records are as following:\n"); for(tempi=0;tempi<tempiNum;tempi++) printf("%s\t",FieldSet[tempi].sFieldName); for(tempi=0;tempi<jNum;tempi++){ printf("\n"); for(tempi1=0;tempi1<iNum;tempi1++){ fread(temps,sizeof(char),FILE_NAME_LENGTH,fp); printf("%s\t",temps); } } bFound=1; } else fread(recordset,sizeof(char),FILE_NAME_LENGTH*jNum*iNum,fp); free(temps1); } if(!bFound)printf("\nNo such a table in %s",dbf); break; case '2': exit(0); } /*end case*/ } /* end do while*/ } /*end program*/