DarkSide SQL Mini Version 1, The embedded database

/**
Copyright 2000 - 2003 LogicMatrix. All rights reserved. 

This software is distributed under the LogicMatrix Free Software License. This software may be used for any purpose, personal or commercial. Redistributions in binary /source code form are permitted. Commercial redistribution of larger works derived from, or works which bundle this software requires a "Commercial Redistribution License" which can be purchased from LogicMatrix. Contact LogicMatrix for details

Redistributions qualify as Free and non-commercial under one of the following terms:

1) Redistributions are made at no charge beyond the reasonable cost of materials and delivery.
2) Redistributions in binary/source code form must reproduce this Copyright Notice,these license terms, and the disclaimer/limitation of liability set forth as below, in the documentation and/or other materials
provided with the distribution.

Disclaimer
==========
The Software is provided on an "AS IS" basis. No warranty is
provided that the Software is free of defects, or fit for a
particular purpose. 

Limitation of Liability 
=======================
LogicMatrix shall not be liable for any damages suffered by the Licensee or any third party resulting from use of the Software.


**/

/**
	update.cpp

	Purpose: Defines classes to parse an UPDATE command

	Author: Vijay Mathew Pandyalakal
	Date:	21/11/2003
	Copyright: logicmatrix
**/

#include <string>
#include <vector>
using namespace std;

#include "db_cxx.h"

#include "sql_lexer.h"
using namespace dsqlm;

#include "mydate.h"
using namespace openutils;

#include "dsql_m_structs.h"
#include "bridge.h"
#include "rec.h"
#include "cmpr.h"
#include "unique.h"
#include "update.h"
#include "sql_utils.h"
#include "bdb_index.h"
using namespace dsqlm;

Update::Update(const char* sql,Database* db) {
	if(db == 0) {
		throw DsqlMException("Update.cpp - database not inited");
	}
	m_db = db;
	this->sql = sql;
}

void Update::setSql(const char* sql) {
	this->sql = sql;
}

long Update::parse() {
	SQLLexer lexer(sql.c_str());
	vector<string> vct = lexer.tokenize();	
	int sz = vct.size();
	if(sz < 6) {
		throw DsqlMException("Not a valid UPDATE command");
	}
	string s = vct[0];
	if((strcmpi(s.c_str(),"UPDATE")) != 0) {
		throw DsqlMException("Not a valid UPDATE command");
	}
	s = vct[1];
	Table table(s.c_str(),m_db);
	table.open();	
	SQLUtils utils(m_db);
	int wpos = utils.findPos(vct,"WHERE");
	int end = wpos;
	if(end < 0) {
		end = sz;
	}
	char err_buff[151];
	TokenType tt = KW_SET;
	vector<Column> vct_update_cols;
	vector<string> vct_new_vals;
	for(int i=2;i<end;i++) {
		s = vct[i];
		if(tt == KW_SET) {
			if(strcmpi(s.c_str(),"SET") != 0) {
				sprintf(err_buff,"Expected SET at %d",(i+1));
				throw DsqlMException(err_buff);
			}
			tt = ID;
		}else if(tt == ID) {
			Column col = table.getCol(s.c_str());
			vct_update_cols.push_back(col);
			tt = COPR;
		}else if(tt == COPR) {
			if(s != "=") {
				sprintf(err_buff,"Expected = at %d",(i+1));
				throw DsqlMException(err_buff);
			}
			tt = ANY;
		}else if(tt == ANY) {
			vct_new_vals.push_back(s);
			tt = COMMA;
		}else if(tt == COMMA) {
			if(s != ",") {
				sprintf(err_buff,"Expected , at %d",(i+1));
				throw DsqlMException(err_buff);
			}
			tt = ID;
		}
	}
	if(vct_update_cols.size() != vct_new_vals.size()) {
		throw DsqlMException("Not enough values");
	}
	long ret = 0;
	if(wpos < 0) { // no WHERE clause
		Rec rec(&table,m_db);
		rec.openCursor();
		long pos = 0;
		Unique uk(&table,m_db);
		char pos_str[24];
		while(rec.next(&pos)) {		
			if(rec.isDeleted()) continue;
			sprintf(pos_str,"%d",pos);			
			for(i=0;i<vct_update_cols.size();i++) {
				Column col = vct_update_cols[i];
				string val = vct_new_vals[i];				
				string old_val = rec.getField(col.getId());
				char *tmp_val = new char[col.getSize() + 1];
				try {
					rec.updateField(col.getId(),val.c_str(),tmp_val);
					if(col.isUnique() == TRUE) {
						if(uk.check(col,val.c_str(),pos)) {
							sprintf(err_buff,"Duplicates not allowed for %s",col.getTitle().c_str());
							delete[] tmp_val;
							throw DsqlMException(err_buff);
						}else {			
							char db_name[101];
							sprintf(db_name,"%s\\%s_%s_x",m_db->getDBName().c_str(),
								table.getName().c_str(),
								col.getTitle().c_str());
							BdbIndex bdb(db_name,false);
							bdb.del(old_val.c_str());
							bdb.put(tmp_val,pos_str);							
						}
					}else if(col.isIndexed() == TRUE) {		
						char db_name[101];
						sprintf(db_name,"%s\\%s_%s_x",m_db->getDBName().c_str(),
							table.getName().c_str(),
							col.getTitle().c_str());
						BdbIndex bdb(db_name,false);
						bdb.del(old_val.c_str(),pos_str);
						bdb.put(tmp_val,pos_str);						
					}				
				}catch(DsqlMException ex) {
					delete[] tmp_val;
					throw DsqlMException(ex.getMessage().c_str());
				}								
				delete[] tmp_val;
			}
			rec.write(pos);
			ret++;
		}
	}else { // WHERE clause
		vector<long> vct_pos;
		/**
		Copied from select.cpp
		**/		
		TokenType tt = ID;		
		vector<Column> vct_cols;
		vector<ComparissonOperator> vct_coprs; 
		vector<string> vct_vals;
		vector<LogicalOperator> vct_loprs;
		SQLUtils utils(m_db);
		wpos++;
		for(int i=wpos;i<sz;i++) {
			s = vct[i];
			if(tt == ID) {
				Column col = table.getCol(s.c_str());
				tt = COPR;
				vct_cols.push_back(col);
			}else if(tt == COPR) {
				vct_coprs.push_back(utils.createComparissonOperator(s.c_str()));
				tt = ANY;
			}else if(tt == ANY) {
				vct_vals.push_back(s);
				tt = LOPR;
			}else if(tt == LOPR) {
				vct_loprs.push_back(utils.createLogicalOperator(s.c_str()));
				tt = ID;
			}else {
				char err_buff[50];
				sprintf(err_buff,"Unexpected token at %d",(i+1));
			}
		}
		Cmpr cmpr(&table,m_db,vct_cols,vct_coprs,vct_vals,vct_loprs);
		cmpr.run();
		long csz = cmpr.getCursorLength();
		for(long k=0;k<csz;k++) {
			vct_pos.push_back(cmpr.getPos(k));
		}
		/**
		**/

		// updation
		Rec rec(&table,m_db);				
		Unique uk(&table,m_db);
		char pos_str[24];
		for(k=0;k<vct_pos.size();k++) {
			long pos = vct_pos[k];
			rec.read(pos);
			if(rec.isDeleted()) continue;
			sprintf(pos_str,"%d",pos);
			for(i=0;i<vct_update_cols.size();i++) {
				Column col = vct_update_cols[i];
				string val = vct_new_vals[i];				
				string old_val = rec.getField(col.getId());
				char *tmp_val = new char[col.getSize() + 1];
				try {
					rec.updateField(col.getId(),val.c_str(),tmp_val);
					if(col.isUnique() == TRUE) {						
						if(uk.check(col,tmp_val,pos)) {
							sprintf(err_buff,"Duplicates not allowed for %s",col.getTitle().c_str());
							//delete[] tmp_val;
							throw DsqlMException(err_buff);
						}else {					
							char db_name[101];
							sprintf(db_name,"%s\\%s_%s_x",m_db->getDBName().c_str(),
								table.getName().c_str(),
								col.getTitle().c_str());
							BdbIndex bdb(db_name,false);
							bdb.del(old_val.c_str());
							bdb.put(tmp_val,pos_str);							
						}
					}else if(col.isIndexed() == TRUE) {						
						char db_name[101];
						sprintf(db_name,"%s\\%s_%s_x",m_db->getDBName().c_str(),
							table.getName().c_str(),
							col.getTitle().c_str());
						BdbIndex bdb(db_name,false);
						bdb.del(old_val.c_str(),pos_str);
						bdb.put(tmp_val,pos_str);						
					}				
				}catch(DsqlMException ex) {
					delete[] tmp_val;
					throw DsqlMException(ex.getMessage().c_str());
				}								
				delete[] tmp_val;
			}
			rec.write(pos);
			ret++;
		}
	}
	return ret;
}