Improve errors msgs, generalise find and add delete query

2 files changed, 39 insertions, 85 deletions

diff --git a/query.cpp b/query.cpp
index a753472..8dee06f 100644
--- a/query.cpp
+++ b/query.cpp
@@ -26,10 +26,10 @@ void CreateQuery::setHeader(const ColHeader *hd){
 }
 
 QueryResult CreateQuery::execute(map<string,Table> &tables){
-	if(nc==0)return QueryResult(0,"zero nc");
-	if(header==NULL)return QueryResult(0,"null header");
+	if(nc==0)return QueryResult(0,"zero nc (CQ:ex)");
+	if(header==NULL)return QueryResult(0,"null header (CQ:ex)");
 	const map<string,Table>::const_iterator tit=tables.find(tablename);
-	if(tit!=tables.cend())return QueryResult(0,"existing table");
+	if(tit!=tables.cend())return QueryResult(0,"existing table (CQ:ex)");
 	tables.emplace(piecewise_construct,
 	               forward_as_tuple(tablename),
 	               forward_as_tuple(tablename,nc,header));
@@ -40,11 +40,14 @@ QueryResult CreateQuery::execute(map<string,Table> &tables){
 FindQuery::FindQuery(void):limit(-1){};
 
 pair<vector<map<string,Row>::const_iterator>,string> FindQuery::executeIterators(map<string,Table> &tables){
-	if(limit==0)return {{},"zero limit"};
-	int i,j;
 	const map<string,Table>::const_iterator tit=tables.find(tablename);
-	if(tit==tables.cend())return {{},"non-existent table"};
-	const Table &table=tit->second;
+	if(tit==tables.cend())return {{},"non-existent table (FQ:eI)"};
+	return executeIterators(tit->second);
+}
+
+pair<vector<map<string,Row>::const_iterator>,string> FindQuery::executeIterators(const Table &table){
+	if(limit==0)return {{},"zero limit (FQ:eI)"};
+	int i,j;
 
 	for(i=0;i<(int)where.size();i++){
 		if(where[i].col==0)break;
@@ -82,46 +85,14 @@ pair<vector<map<string,Row>::const_iterator>,string> FindQuery::executeIterators
 }
 
 QueryResult FindQuery::execute(map<string,Table> &tables){
-	if(limit==0)return QueryResult(0,"zero limit");
-	int i,j;
-	const map<string,Table>::const_iterator tit=tables.find(tablename);
-	if(tit==tables.cend())return QueryResult(0,"non-existent table");
-	const Table &table=tit->second;
-
-	for(i=0;i<(int)where.size();i++){
-		if(where[i].col==0)break;
+	pair<vector<map<string,Row>::const_iterator>,string> ret=executeIterators(tables);
+	QueryResult qres;
+	qres.res=ret.first.size();
+	for(int i=0;i<qres.res;i++){
+		qres.rows.push_back(ret.first[i]->second);
 	}
-	if(i!=(int)where.size()){
-		const map<string,Row>::const_iterator rit=table.rows.find(serialise(table.header[0],where[i].value));
-		if(rit==table.rows.cend())return QueryResult(0);
-		const Row &row=rit->second;
-		for(j=0;j<(int)where.size();j++){
-			if(j==i)continue;
-			const int col=where[j].col;
-			if(riCompare(table.header[col],row.items[col],where[j].value)!=0)break;
-		}
-		if(j!=(int)where.size())return QueryResult(0);
-		else return QueryResult(1,{row});
-	}
-
-	typedef map<string,Row>::const_iterator cit_t;
-
-	cit_t end=table.rows.cend();
-	QueryResult ret;
-	for(cit_t it=table.rows.cbegin();it!=end;it++){
-		//if(serialise(it->second.table->header[0],it->second.items[0])==key)
-		//	ret.emplace_back(it->second);
-		for(i=0;i<(int)where.size();i++){
-			const int col=where[i].col;
-			if(riCompare(table.header[col],it->second.items[col],where[i].value)!=0)break;
-		}
-		if(i==(int)where.size()){
-			ret.res++;
-			ret.rows.emplace_back(it->second);
-			if(ret.res==limit)return ret;
-		}
-	}
-	return ret;
+	qres.msg=ret.second;
+	return qres;
 }
 
 
@@ -130,13 +101,13 @@ InsertQuery::InsertQuery(Row &&_r):row(move(_r)){}
 
 QueryResult InsertQuery::execute(map <string,Table> &tables){
 	map<string,Table>::iterator tit=tables.find(tablename);
-	if(tit==tables.end())return QueryResult(0,"non-existent table");
+	if(tit==tables.end())return QueryResult(0,"non-existent table (IQ:ex)");
 	Table &table=tit->second;
 
-	if(table.nc!=row.nc)return QueryResult(0,"non-conformant row width");
+	if(table.nc!=row.nc)return QueryResult(0,"non-conformant row width (IQ:ex)");
 	const string primkey=serialise(table.header[0],row.items[0]);
 	const map<string,Row>::const_iterator rit=table.rows.find(primkey);
-	if(rit!=table.rows.cend())return QueryResult(0,"existing primary key");
+	if(rit!=table.rows.cend())return QueryResult(0,"existing primary key (IQ:ex)");
 	table.rows.insert(make_pair(primkey,row));
 	return QueryResult(1);
 }
@@ -145,43 +116,18 @@ QueryResult InsertQuery::execute(map <string,Table> &tables){
 DeleteQuery::DeleteQuery(void){};
 
 QueryResult DeleteQuery::execute(map<string,Table> &tables){
-	int i,j;
-	map<string,Table>::iterator tit=tables.find(tablename);
-	if(tit==tables.end())return QueryResult(0,"non-existent table");
+	const map<string,Table>::iterator tit=tables.find(tablename);
+	if(tit==tables.cend())return {{},"non-existent table (DQ:ex)"};
 	Table &table=tit->second;
 
-	for(i=0;i<(int)where.size();i++){
-		if(where[i].col==0)break;
-	}
-	if(i!=(int)where.size()){
-		const map<string,Row>::const_iterator rit=table.rows.find(serialise(table.header[0],where[i].value));
-		if(rit==table.rows.cend())return QueryResult(0);
-		const Row &row=rit->second;
-		for(j=0;j<(int)where.size();j++){
-			if(j==i)continue;
-			const int col=where[j].col;
-			if(riCompare(table.header[col],row.items[col],where[j].value)!=0)break;
-		}
-		if(j!=(int)where.size())return QueryResult(0);
-		table.rows.erase(rit);
-		return QueryResult(1);
-	}
-
-	typedef map<string,Row>::const_iterator cit_t;
-
-	cit_t end=table.rows.cend();
-	QueryResult ret;
-	for(cit_t it=table.rows.cbegin();it!=end;it++){
-		//if(serialise(it->second.table->header[0],it->second.items[0])==key)
-		//	ret.emplace_back(it->second);
-		for(i=0;i<(int)where.size();i++){
-			const int col=where[i].col;
-			if(riCompare(table.header[col],it->second.items[col],where[i].value)!=0)break;
-		}
-		if(i==(int)where.size()){
-			ret.res++;
-			ret.rows.emplace_back(it->second);
-		}
+	FindQuery fqu;
+	fqu.tablename=tablename;
+	fqu.where=where;
+	pair<vector<map<string,Row>::const_iterator>,string> ret=fqu.executeIterators(table);
+	if(ret.second.size()!=0)return QueryResult(0,ret.second);
+	map<string,Row>::const_iterator it;
+	for(int i=0;i<ret.first.size();i++){
+		table.rows.erase(ret.first[i]);
 	}
-	return ret;
+	return QueryResult(ret.first.size());
 }
diff --git a/query.h b/query.h
index 2b4d17d..1e06264 100644
--- a/query.h
+++ b/query.h
@@ -11,6 +11,7 @@ using namespace std;
 struct WhereClause{
 	int col;
 	RowItem value;
+
 	WhereClause(void);
 	WhereClause(const int _c,const RowItem &_v);
 };
@@ -20,6 +21,7 @@ struct QueryResult{
 	int res;
 	vector<Row> rows;
 	string msg; //empty message indicates success
+
 	QueryResult(void);
 	QueryResult(int);
 	QueryResult(int,const vector<Row>&);
@@ -30,12 +32,14 @@ struct QueryResult{
 
 struct Query{
 	string tablename;
+
 	virtual QueryResult execute(map<string,Table>&);
 };
 
 struct CreateQuery : public Query{
 	int nc;
 	ColHeader *header;
+
 	CreateQuery(void);
 	void setHeader(const ColHeader *hd);
 	QueryResult execute(map<string,Table> &tables);
@@ -44,13 +48,16 @@ struct CreateQuery : public Query{
 struct FindQuery : public Query{
 	unsigned int limit; //-1=unlimited
 	vector<WhereClause> where;
+
 	FindQuery(void);
 	pair<vector<map<string,Row>::const_iterator>,string> executeIterators(map<string,Table> &tables);
+	pair<vector<map<string,Row>::const_iterator>,string> executeIterators(const Table &table);
 	QueryResult execute(map<string,Table> &tables);
 };
 
 struct InsertQuery : public Query{
 	Row row;
+
 	InsertQuery(const Row &_r);
 	InsertQuery(Row &&_r);
 	QueryResult execute(map<string,Table> &tables);
@@ -58,6 +65,7 @@ struct InsertQuery : public Query{
 
 struct DeleteQuery : public Query{
 	vector<WhereClause> where;
+
 	DeleteQuery(void);
 	QueryResult execute(map<string,Table> &tables);
 };