📄 common.cpp
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}
else
{
count++;
}
}
fclose(fp);
printf("共影响了[%d] 条记录\n",count);
}
return true;
}
//用于生成字段集合
int AnalysisSelectFieldSet(vector<string> &pCommandField,RecordNodeSet vRecordSet)
{
if(strcmp(pCommandField[1].c_str(), "*") == 0)
{
if(strcmp(pCommandField[2].c_str(),"from") == 0)
return 2;
else
return false;
}
else
{
int iIndex = 1;
while(pCommandField.size() > iIndex)
{
if(strcmp(pCommandField[iIndex].c_str(), "from") == 0)
return iIndex;
else if(strcmp(pCommandField[iIndex].c_str() ,",") == 0)
{
iIndex++;
}
else
{
if(!CheckRuleForString(pCommandField[iIndex].c_str()))
return false;
vRecordSet.vSelectField.push_back(pCommandField[iIndex]);
iIndex++;
}
}
}
return false;
}
//Select语句主要有如下三种方式:
// select * [fieldname] from lid
// select from lid where xxx = xx
// select [*] fieldname1,fieldname2 from xxx where xxx = xxx
bool ParseSelectRecord(vector<string> &pCommandField,RecordNodeSet &vRecordSet,Tree *pTree,string &strTableName)
{
//第一部分用于分析where语句之前的内容
int iIndex = AnalysisSelectFieldSet(pCommandField,vRecordSet);
if(iIndex == false)
{
printf("执行Select字段选择时出错\n");
return false;
}
iIndex++;
//进行表的分析
int iTableIndex = 2;
if(pCommandField.size() > iIndex)
{
if(!IsTableExist(pCommandField[iIndex].c_str()))
{
printf("要操作的表不存在\n");
return false;
}
iTableIndex = iIndex;
strTableName = pCommandField[iIndex];
ReadFiledListStruct(vRecordSet.vFieldNode,pCommandField[iIndex].c_str());
//检查当前的字段信息，同时进行排序,注意若值为*则别当别论
if(iIndex > 3)
{
vRecordSet.bIsAllField = false;//标识当前不为全部的结果集
vector<string>::iterator pStr;
for(pStr = vRecordSet.vSelectField.begin(); pStr != vRecordSet.vSelectField.end(); pStr++)
{
bool bFlag = false;
vector<FieldNode>::iterator pData;
for(pData = vRecordSet.vFieldNode.begin(); pData != vRecordSet.vFieldNode.end(); pData++)
{
if(strcmp(pStr->c_str(), pData->strFieldName) == 0)
{
bFlag = true;
}
}
if(!bFlag)
{
printf("不能识别的字段\n",pStr->c_str());
return false;
}
}
}
}
else
return false;
iIndex++;
if(pCommandField.size() == iIndex)
return true;
else if(pCommandField.size() > iIndex)
{
//进行where的分析
if(!AnalysisWhereStatment(pCommandField,pTree,iIndex,iTableIndex))
{
printf("where语句有问题\n");
return false;
}
}
return true;
}
bool ExecSelectRecord(const char *pStrTableName,RecordNodeSet &vRecordSet,Tree *pTree)
{
if(pTree == NULL)
{
return false;
}
vector<IndexData> vIndexHead;
if(!ReadIndexRecord(vIndexHead,pStrTableName))
{
printf("读取索引数据失败\n");
return false;
}
if(pTree->vAndSet.size() <= 0)
{
string strFileName ;
strFileName = "data\\" ;
strFileName.append(g_strCurrentDBName);
strFileName += "\\" ;
strFileName.append(pStrTableName);
strFileName += ".ltd";
FILE *pFile;
if((pFile=fopen(strFileName.c_str(),"rb"))==NULL)
{
printf("创建索引文件失败\n");
return false;
}
int iCount = 0;
string strValue;
RecordNode rNode;
while(iCount < vIndexHead.size())
{
fseek(pFile,vIndexHead[iCount].GetPosition(),0);
while(!feof(pFile))
{
char ch = fgetc(pFile);
char nextCh;
switch(ch)
{
case '&':
nextCh = fgetc(pFile);
if(nextCh == '&')
{
//进入下一条记录，或者当前是首记录
//如果当前从开始字符串起
if(rNode.vStrValue.size() <= 0)
break;
else
{
rNode.vStrValue.push_back(strValue);
vRecordSet.AddRecord(rNode);
rNode.vStrValue.clear();
strValue = "";
goto Lable;
}
}
else
{
//下一个字段信息
rNode.vStrValue.push_back(strValue);
strValue = "";
strValue += nextCh;
}
break;
case '\\':
strValue += fgetc(pFile);
break;
case EOF:
rNode.vStrValue.push_back(strValue);
vRecordSet.AddRecord(rNode);
rNode.vStrValue.clear();
strValue = "";
break;
default:
strValue += ch;
break;
}
}
Lable: iCount++;
}
fclose(pFile);
printf("共查找了[%d] 条记录\n",iCount);
return true;
}
string strValue;
const char *pStr = pTree->vAndSet[0].strValue.c_str();
if(pStr[0] == '\'' || pStr[0] == '\"')
{
if(!CheckRuleForInsertTextType(strValue,pTree->vAndSet[0].strValue))
{
printf("当前的值出现问题");
return false;
}
pTree->vAndSet[0].iFieldType = VARCHAR_TYPE;
}
else
{
strValue = pStr;
pTree->vAndSet[0].iFieldType = INT_TYPE;
}
//进行数据分析
vector<long> vDataPosition;
vector<IndexData>::iterator pData;
bool bModifyFlag = false;
for(pData = vIndexHead.begin(); pData != vIndexHead.end(); pData++)
{
switch( pTree->vAndSet[0].iProcessType )
{
case BIG_OPERATOR:
if(strValue < pData->strValue)
{
pData->bFlag = true;
vDataPosition.push_back(pData->GetPosition());
bModifyFlag = true;
}
break;
case EQUAL_OPERATOR:
if(strValue == pData->strValue)
{
pData->bFlag = true;
vDataPosition.push_back(pData->GetPosition());
bModifyFlag = true;
}
break;
case NOEQUAL_OPERATOR:
if(strValue != pData->strValue)
{
pData->bFlag = true;
vDataPosition.push_back(pData->GetPosition());
bModifyFlag = true;
}
break;
case BIG_EQUAL_OPERATOR:
if(strValue <= pData->strValue)
{
pData->bFlag = true;
vDataPosition.push_back(pData->GetPosition());
bModifyFlag = true;
}
break;
case SMALL_OPERATOR:
if(strValue > pData->strValue)
{
pData->bFlag = true;
vDataPosition.push_back(pData->GetPosition());
bModifyFlag = true;
}
break;
case SMALL_EQUAL_OPERATOR:
if(strValue >= pData->strValue)
{
pData->bFlag = true;
vDataPosition.push_back(pData->GetPosition());
bModifyFlag = true;
}
break;
case LIKE_OPERATOR:
break;
case BWTEEN_OPERATOR: //between语句
break;
}
}
//进行数据修改的操作，其操作办法是重写当前的值
if(bModifyFlag)
{
string strFileName ;
strFileName = "data\\" ;
strFileName.append(g_strCurrentDBName);
strFileName += "\\" ;
strFileName.append(pStrTableName);
strFileName += ".ltd";
FILE *pFile;
if((pFile=fopen(strFileName.c_str(),"rb"))==NULL)
{
printf("创建索引文件失败\n");
return false;
}
int iCount = 0;
string strValue;
RecordNode rNode;
while(iCount < vDataPosition.size())
{
fseek(pFile,vDataPosition[iCount],0);
while(!feof(pFile))
{
char ch = fgetc(pFile);
char nextCh;
switch(ch)
{
case '&':
nextCh = fgetc(pFile);
if(nextCh == '&')
{
//进入下一条记录，或者当前是首记录
//如果当前从开始字符串起
if(rNode.vStrValue.size() <= 0)
break;
else
{
rNode.vStrValue.push_back(strValue);
vRecordSet.AddRecord(rNode);
rNode.vStrValue.clear();
strValue = "";
goto Lable1;
}
}
else
{
//下一个字段信息
rNode.vStrValue.push_back(strValue);
strValue = "";
strValue += nextCh;
}
break;
case '\\':
strValue += fgetc(pFile);
break;
case EOF:
rNode.vStrValue.push_back(strValue);
vRecordSet.AddRecord(rNode);
break;
default:
strValue += ch;
break;
}
}
Lable1: iCount++;
}
fclose(pFile);
printf("共查找了[%d] 条记录\n",iCount);
}
return true;
}
//分析更新的字段列表 Update xxx set field = fw , fe = 2f where name > 23
int AnalysisUpdateFieldSet(vector<string> &pCommandField,vector<UpdateField> &vUpdateFieldList)
{
int iIndex = 1;
if(!IsTableExist(pCommandField[1].c_str()))
{
printf("当前要操作表不存在\n");
return false;
}
iIndex++;
if(iIndex >= pCommandField.size())
{
printf("%s\n",COMMANDLENGTHISNOTENOUGH);
return false;
}
if(!strcmp(pCommandField[iIndex].c_str(),"set") == 0)
{
printf("缺少Set符，请检查输入\n");
return false;
}
iIndex++;
//进行分析字段列表,中间以逗号进行间隔
vector<FieldNode> pFiledList;
ReadFiledListStruct(pFiledList,pCommandField[1].c_str());
vector<FieldNode>::iterator pData;
while( (pCommandField.size() > iIndex)
&& (strcmp(pCommandField[iIndex].c_str(), "where") != 0))
{
UpdateField pNode;
//进行字段分析
if(!CheckRuleForString(pCommandField[iIndex].c_str()))
{
printf("分析的字段不符合规则[%s]\n",pCommandField[iIndex].c_str());
return false;
}
int iCount = -1;
for(pData = pFiledList.begin(); pData != pFiledList.end(); pData++)
{
iCount++;
if(strcmp(pData->strFieldName,pCommandField[iIndex].c_str()) == 0)
{
pNode.strFieldName = pCommandField[iIndex].c_str();
pNode.iPosition = iCount;
pNode.isPrimary = pData->bIsPrimaryKey;
string strValue;
if(++iIndex >= pCommandField.size())
{
printf("后面要一个操作符\n");
return false;
}
if(strcmp(pCommandField[iIndex].c_str(),"=") != 0)
{
printf("当前第[%d]个操作符，应该是个=\n",iIndex+1);
return false;
}
//进行设定当前的字段值
if(++iIndex >= pCommandField.size())
{
printf("后面要一个操作符\n");
return false;
}
switch(pData->iFieldType)
{
case VARCHAR_TYPE:
if(!CheckRuleForInsertTextType(strValue,pCommandField[iIndex]))
{
printf("字段[%s]值[%s],要插入的文本不符合规则\n",pData->strFieldName,pCommandField[iIndex].c_str());
return false;
}
if(strValue.length() > pData->iValueLength)
{
printf("字段[%s]值[%s]越界\n",pData->strFieldName,strValue.c_str());
return false;
}
pNode.strUpdateValue = strValue;
break;
case INT_TYPE:
if(!CheckRuleForNum(pCommandField[iIndex].c_str()))
{
printf("字段[%s]值[%s]不符合整数规则\n",pData->strFieldName,pCommandField[iIndex].c_str());
return false;
}
if(pData->bIsCheck)
{
long lValue = atol(pCommandField[iIndex].c_str());
if(!(lValue >= pData->lStartValue && lValue <= pData->IEndValue))
{
printf("输入的整形[%ld]没有通过规则检查,规则下限[%ld],规则上限[%ld]\n",lValue,pData->lStartValue,pData->IEndValue);
return false;
}
}
pNode.strUpdateValue = strValue;
break;
case TEXT_TYPE:
if(!CheckRuleForInsertTextType(strValue,pCommandField[iIndex]))
{
printf("字段[%s]值[%s],要插入的文本不符合规则\n",pData->strFieldName,pCommandField[iIndex].c_str());
return false;
}
pNode.strUpdateValue = strValue;
break;
case DATE_TYPE:
if(!CheckRuleForInsertTextType(strValue,pCommandField[iIndex]))
{
printf("字段[%s]值[%s],要插入的文本不符合规则\n",pData->strFieldName,pCommandField[iIndex].c_str());
return false;
}
pNode.strUpdateValue = strValue;
break;
default:
printf("不能识别的字段类型\n");
return false;
}
}
}
vUpdateFieldList.push_back(pNode);
//进行逗号的判断
if(++iIndex >= pCommandField.size())
{
printf("后面要一个操作符\n");
return false;
}
if((strcmp(pCommandField[iIndex].c_str(),",") != 0)
&& (strcmp(pCommandField[iIndex].c_str(),"where") != 0))
{
printf("当前第[%d]个操作符，应该是个, 或where\n",iIndex+1);
return false;
}
if(strcmp(pCommandField[iIndex].c_str(),"where") == 0)
{
return iIndex;
}
//进行下一字段的分析
iIndex++;
}
return iIndex;
}
//进行解析更新的字段
bool ParseUpdateRecord(vector<string> &pCommandField,vector<UpdateField> &vUpdateFieldList,Tree *pTree,string &strTableName)
{
int iIndex = AnalysisUpdateFieldSet(pCommandField,vUpdateFieldList);
if(iIndex == false)
{
printf("分析更新字段列表时出错\n");
return false;
}
if(!AnalysisWhereStatment(pCommandField,pTree,iIndex,1))
{
printf("分析Where语句失败\n");
return false;
}
return true;
}
//选中一条记录
bool FindOneRecord(FILE *pFile,long lPosition,RecordNode &vRecord)
{
fseek(pFile,lPosition,0);
string strValue;
while(!feof(pFile))
{
char ch = fgetc(pFile);
char nextCh;
switch(ch)
{
case '&':
nextCh = fgetc(pFile);
if(nextCh == '&')
{
//进入下一条记录，或者当前是首记录
//如果当前从开始字符串起
if(vRecord.vStrValue.size() <= 0)
break;
else
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