drop.c

一个c语言开发的小型的dbms系统

#ifndef lint
static char const 
yyrcsid[] = "$FreeBSD: src/usr.bin/yacc/skeleton.c,v 1.28 2000/01/17 02:04:06 bde Exp $";
#endif
#include <stdlib.h>
#define YYBYACC 1
#define YYMAJOR 1
#define YYMINOR 9
#define YYLEX yylex()
#define YYEMPTY -1
#define yyclearin (yychar=(YYEMPTY))
#define yyerrok (yyerrflag=0)
#define YYRECOVERING() (yyerrflag!=0)
static int yygrowstack();
#define YYPREFIX "yy"
#line 1 "no_help.y"

#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include "struct.h"
#include "error.h"
/*#include "wbexe.c"*/	/*里面有语法树显示，初步语义检查，数据字典显示*/



char	sql[256];		/*用于读输入行的*/
int	sqlnum=0;		/*用于表示读到了第几个字符*/
char	*error_var;	/*用来接收各个程序返回的错误提示*/
int 	finish_flag;	/*用来控制主程序的循环，当用户输入"QUIT"时，它的值为1，表示应用结束*/

_dic_type		dic;	/*用来存放数据字典*/

_selectedfields_type	*sf_var1,*sf_end;
_selectedtables_type	*st_var1,*st_end;
_createfieldsdef_type	*cfdef_end;
_insertvalues_type		*iv_var1,*iv_end;
_insertfields_type		*if_var1,*if_end;

#line 27 "no_help.y"
typedef union			/*定义yylval的格式*/
{	char			char_var;
	char			*yych;
	/*---------------------------------属于select语法树的类型*/
	_selectedfields_type	*sf_var;
	_selectedtables_type	*st_var;
	_selectstruct_type		*ss_var;
	/*---------------------------------属于create语法树的类型*/
	_createfieldsdef_type	*cfdef_var;
	_createstruct_type		*cs_var;
	/*---------------------------------DROP-----------------*/
	_dropstruct_type	*drs_var;
	/*---------------------------------属于insert语法树的类型*/
	_insertfields_type		*if_var;
	_insertvalues_type		*iv_var;
	_insertstruct_type		*is_var;
	/*---------------------------------属于delete语法树的类型*/
	_deletestruct_type		*ds_var;
	_conditions_type		*cons_var;

} YYSTYPE;
#line 64 "drop.c"
#define YYERRCODE 256
#define SELECT 257
#define FROM 258
#define WHERE 259
#define IDENTIFIER 260
#define NUMBER 261
#define CREATE 262
#define TABLE 263
#define CHAR 264
#define INT 265
#define DATE 266
#define DROP 267
#define INSERT 268
#define INTO 269
#define VALUES 270
#define DELETE 271
#define AND 272
#define OR 273
#define QUIT 274
#define SHOW 275
#define TABLES 276
#define TABLE_DIC 277
#define OF 278
#define COLS 279
const short yylhs[] = {                                        -1,
    0,    0,    0,    0,    0,    0,    0,    0,    1,    1,
    2,    2,    5,    5,    3,    3,    4,    4,    7,    6,
    8,    8,   12,   10,   10,   11,    9,    9,    9,   13,
   18,   15,   15,   14,   14,   16,   16,   17,   17,   17,
   19,   19,   24,   24,   24,   20,   21,   22,   22,   22,
   22,   23,   23,   25,   25,   25,   26,   26,   26,
};
const short yylen[] = {                                         2,
    1,    1,    1,    1,    1,    2,    2,    2,    5,    7,
    1,    1,    1,    3,    1,    3,    1,    3,    1,    1,
    1,    1,    7,    1,    3,    2,    4,    1,    1,    4,
    9,    0,    3,    1,    3,    1,    3,    3,    3,    1,
    6,    4,    1,    7,    7,    3,    1,    1,    3,    3,
    1,    1,    3,    1,    1,    1,    2,    2,    4,
};
const short yydefred[] = {                                      0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    1,    0,   52,    2,    3,    4,    5,   43,    0,   47,
    0,    0,   12,    0,    0,   15,    0,   17,    0,    0,
    0,    0,    7,   57,   58,    0,    0,    0,   54,   55,
   56,    0,    6,    8,    0,    0,    0,   20,    0,    0,
    0,    0,    0,    0,   19,   53,   51,    0,   46,   48,
    0,   13,   16,   18,    0,   30,    0,    0,    0,   42,
   59,    0,    0,    0,    0,    0,    9,    0,    0,    0,
   24,   34,    0,    0,    0,    0,    0,   49,   50,    0,
   14,    0,   28,   29,   26,    0,    0,    0,   33,    0,
   41,    0,    0,   10,    0,   25,   23,   35,   40,    0,
    0,   36,   44,   45,    0,    0,    0,    0,    0,   27,
   38,   39,   37,   31,
};
const short yydgoto[] = {                                      10,
   11,   24,   25,   26,   61,   12,   13,    0,   95,   80,
   81,   14,   15,   83,   68,  111,  112,   16,   17,   18,
   19,   59,   20,   21,   42,   22,
};
const short yysindex[] = {                                    -40,
  -34,    0, -256, -249, -251, -234,  -18, -266,  -39,    0,
    0,  -20,    0,    0,    0,    0,    0,    0,  -33,    0,
   -7,   -4,    0, -202,   13,    0,   12,    0, -201, -201,
 -201, -201,    0,    0,    0, -218,   21, -197,    0,    0,
    0,  -37,    0,    0, -201, -196, -197,    0,   25,    9,
   27,  -55, -201, -238,    0,    0,    0, -214,    0,    0,
  -23,    0,    0,    0, -197,    0, -197, -200,  -39,    0,
    0,   32,   34,   36,   37,  -39,    0, -201, -221,  -25,
    0,    0,  -21,   38,   18,  -39,  -39,    0,    0,   20,
    0,   40,    0,    0,    0, -197,   22, -197,    0,  -36,
    0,   41,   44,    0, -174,    0,    0,    0,    0, -212,
  -19,    0,    0,    0,   47,   50,   51,  -36,   33,    0,
    0,    0,    0,    0,
};
const short yyrindex[] = {                                      0,
    0,  -29,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0, -167,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
 -177,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,
};
const short yygindex[] = {                                      0,
    0,    0,    0,   48,    0,    8,    4,    0,    0,    0,
   -1,    0,    0,    0,    0,    0,  -22,    0,    0,    0,
    0,    0,   55,   -3,    0,    0,
};
#define YYTABLESIZE 236
const short yytable[] = {                                       9,
    9,   58,  110,   70,   28,   37,   29,   23,   27,   34,
   35,   19,   36,   30,   19,   97,   20,   31,   96,   99,
   78,  119,   98,   32,  118,   38,   39,   41,   40,   19,
   19,   19,   19,   72,   73,   77,   49,   50,   51,   52,
   33,   56,   92,   93,   94,   74,   75,  116,  117,   28,
   64,   43,   62,   27,   44,   45,   46,   47,   48,   53,
   71,   54,   55,    2,   65,   85,   67,   66,   79,   84,
   82,   86,   90,   87,   88,   89,  101,  100,  104,  105,
  107,  113,  102,  103,  114,   91,  115,  120,  121,  122,
   11,  124,   32,   63,  106,  123,   60,    0,    0,   79,
    0,  108,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
    0,    0,    0,   69,    0,    0,    0,    0,    0,    0,
    0,    0,    0,    0,    0,    0,    1,    0,    0,    2,
    2,    3,    2,   57,  109,    2,    4,    5,   19,    0,
    6,    0,    0,    7,    8,   76,
};
const short yycheck[] = {                                      40,
   40,   39,   39,   59,    1,    9,  263,   42,    1,  276,
  277,   41,  279,  263,   44,   41,   46,  269,   44,   41,
   44,   41,   44,  258,   44,   46,   60,   61,   62,   59,
   60,   61,   62,  272,  273,   59,   29,   30,   31,   32,
   59,   38,  264,  265,  266,  260,  261,  260,  261,   46,
   47,   59,   45,   46,   59,  258,   44,   46,  260,  278,
   53,   41,  260,  260,   40,   69,   40,   59,   65,  270,
   67,   40,   76,   40,   39,   39,   59,   40,   59,   40,
   59,   41,   86,   87,   41,   78,  261,   41,   39,   39,
  258,   59,  270,   46,   96,  118,   42,   -1,   -1,   96,
   -1,   98,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,
   -1,   -1,   -1,  259,   -1,   -1,   -1,   -1,   -1,   -1,
   -1,   -1,   -1,   -1,   -1,   -1,  257,   -1,   -1,  260,
  260,  262,  260,  261,  261,  260,  267,  268,  258,   -1,
  271,   -1,   -1,  274,  275,  259,
};
#define YYFINAL 10
#ifndef YYDEBUG
#define YYDEBUG 0
#endif
#define YYMAXTOKEN 279
#if YYDEBUG
const char * const yyname[] = {
"end-of-file",0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,"'\\''","'('","')'","'*'",0,"','",0,"'.'",0,0,0,0,0,0,0,0,0,0,0,0,
"';'","'<'","'='","'>'",0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,"SELECT","FROM","WHERE","IDENTIFIER","NUMBER","CREATE","TABLE",
"CHAR","INT","DATE","DROP","INSERT","INTO","VALUES","DELETE","AND","OR","QUIT",
"SHOW","TABLES","TABLE_DIC","OF","COLS",
};
const char * const yyrule[] = {
"$accept : statement",
"statement : selectsql",
"statement : createsql",
"statement : dropsql",
"statement : insertsql",
"statement : deletesql",
"statement : conditions ';'",
"statement : QUIT ';'",
"statement : show ';'",
"selectsql : SELECT fields_star FROM tables ';'",
"selectsql : SELECT fields_star FROM tables WHERE conditions ';'",
"fields_star : table_fields",
"fields_star : '*'",
"tables : table",
"tables : tables ',' table",
"table_fields : table_field",
"table_fields : table_fields ',' table_field",
"table_field : field",
"table_field : table '.' field",
"field : IDENTIFIER",
"table : IDENTIFIER",
"express : IDENTIFIER",
"express : NUMBER",
"createsql : CREATE TABLE table '(' fieldsdefinition ')' ';'",
"fieldsdefinition : field_type",
"fieldsdefinition : fieldsdefinition ',' field_type",
"field_type : field type",
"type : CHAR '(' NUMBER ')'",
"type : INT",
"type : DATE",
"dropsql : DROP TABLE table ';'",
"insertsql : INSERT INTO table fields_choosed VALUES '(' values ')' ';'",
"fields_choosed :",
"fields_choosed : '(' fields ')'",
"fields : field",
"fields : fields ',' field",
"values : avalue",
"values : values ',' avalue",
"avalue : '\\'' IDENTIFIER '\\''",
"avalue : '\\'' NUMBER '\\''",
"avalue : NUMBER",
"deletesql : DELETE FROM table WHERE conditions ';'",
"deletesql : DELETE FROM table ';'",
"conditions : condition",
"conditions : '(' conditions ')' AND '(' conditions ')'",
"conditions : '(' conditions ')' OR '(' conditions ')'",
"condition : comp_left comp_op comp_right",
"comp_left : table_field_",
"comp_right : table_field_",
"comp_right : '\\'' IDENTIFIER '\\''",
"comp_right : '\\'' NUMBER '\\''",
"comp_right : NUMBER",
"table_field_ : field",
"table_field_ : table '.' field",
"comp_op : '<'",
"comp_op : '>'",
"comp_op : '='",
"show : SHOW TABLES",
"show : SHOW TABLE_DIC",
"show : SHOW COLS OF table",
};
#endif
#if YYDEBUG
#include <stdio.h>
#endif
#ifdef YYSTACKSIZE
#undef YYMAXDEPTH
#define YYMAXDEPTH YYSTACKSIZE
#else
#ifdef YYMAXDEPTH
#define YYSTACKSIZE YYMAXDEPTH
#else
#define YYSTACKSIZE 10000
#define YYMAXDEPTH 10000
#endif
#endif
#define YYINITSTACKSIZE 200
int yydebug;
int yynerrs;
int yyerrflag;
int yychar;
short *yyssp;
YYSTYPE *yyvsp;
YYSTYPE yyval;
YYSTYPE yylval;
short *yyss;
short *yysslim;
YYSTYPE *yyvs;
int yystacksize;
#line 489 "no_help.y"


typedef	struct	tokentype{
	char 	*name; 
	int 	value; 
	}tokentype;

tokentype tokens[] =	/*这里只列出了没有定义类型的终结符*/
{	"SELECT",		SELECT,
	"FROM",		FROM,
	"WHERE",		WHERE,
	"CREATE",		CREATE,
	"DROP",		DROP,
	"TABLE",		TABLE,
	"CHAR",		CHAR,
	"INT",		INT,
	"DATE",		DATE,
	"INSERT",		INSERT,
	"INTO",		INTO,
	"VALUES",		VALUES,
	"DELETE",		DELETE,
	"AND",		AND,
	"OR",		OR,
	"QUIT",		QUIT,
	"SHOW",		SHOW,
	"TABLES",		TABLES,
	"TABLE_DIC",	TABLE_DIC,
	"COLS",		COLS,
	"OF",		OF,
	"\0",		'\0'	
};

int is_number(char *s)	/*用来判断一个字符串是不是数字*/
{
	char *ss;
	ss=s;
	while (*ss!='\0')
	{	if (*ss<'0' || *ss>'9')  
			return(0);
		ss++;
	}
	return(1);
}

void low_to_up(char *s)	/*把一个字符串变为大写的*/
{	unsigned	int i;
	for(i=0;i<strlen(s);i++)
	{	s[i]=toupper(s[i]);
	}
}
int is_token(char *s)	/*用来判断一个字符串是不是一个无类型定义的token*/
{
	char *str;
	int	i=0;
	str=strdup(s);
	low_to_up(str);
	while(1)
	{
		if (strlen(tokens[i].name)==0)	break;	
		if (strcmp(tokens[i].name,str)==0)
		{	free(str);
			return(tokens[i].value);	/*是token，返回对应的值*/
		}
		i++;
	}
	free(str);
	return(0);		/*不是，则返回0*/
}

int is_legal(char s)	/*用来判断一个字符是不是字符串中的合法字符*/
{	int flag=0;
	if(s>='a' && s<='z')	flag=1;
	if(s>='A' && s<='Z')  	flag=1;
	if(s=='_') 	    	flag=1;
	if(s>='0' && s<='9')  	flag=1;
	if(flag==0)  return(0);	/*不是*/
	return(1);		/*是*/
}
		
int is_identifier(char *s)	/*用来判断一个字符串是不是合格的标识符*/
{
	char *ss;
	ss=s;
	while(*ss!='\0')
	{	if(is_legal(*ss)==0)  return(0);
		ss++;
	}
	return(1);
}

void readaword(char *aword)	/*将下一个词读入aword中*/
{
	char ss;
	int  awordnum=0;
	ss=sql[sqlnum];
	while( is_legal(ss))
	{	aword[awordnum]=ss;
		awordnum++;