Start delete query and generalise iterator find

2 files changed, 94 insertions, 2 deletions

diff --git a/query.cpp b/query.cpp
index 2e1606f..a753472 100644
--- a/query.cpp
+++ b/query.cpp
@@ -37,7 +37,49 @@ QueryResult CreateQuery::execute(map<string,Table> &tables){
 }
 
 
-FindQuery::FindQuery(void):limit(-1),sort(0){};
+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;
+
+	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.end())return {{},""};
+		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 {{},""};
+		vector<map<string,Row>::const_iterator> v;
+		v.push_back(rit);
+		return {v,""};
+	}
+
+	typedef map<string,Row>::const_iterator cit_t;
+
+	cit_t end=table.rows.end();
+	pair<vector<map<string,Row>::const_iterator>,string> ret;
+	for(cit_t it=table.rows.begin();it!=end;it++){
+		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.first.push_back(it);
+			if(ret.first.size()==limit)return ret;
+		}
+	}
+	return ret;
+}
 
 QueryResult FindQuery::execute(map<string,Table> &tables){
 	if(limit==0)return QueryResult(0,"zero limit");
@@ -98,3 +140,48 @@ QueryResult InsertQuery::execute(map <string,Table> &tables){
 	table.rows.insert(make_pair(primkey,row));
 	return QueryResult(1);
 }
+
+
+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");
+	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);
+		}
+	}
+	return ret;
+}
diff --git a/query.h b/query.h
index 5018f9d..2b4d17d 100644
--- a/query.h
+++ b/query.h
@@ -43,9 +43,9 @@ struct CreateQuery : public Query{
 
 struct FindQuery : public Query{
 	unsigned int limit; //-1=unlimited
-	int sort; //0=no sort, 1=sort, -1=reverse sort
 	vector<WhereClause> where;
 	FindQuery(void);
+	pair<vector<map<string,Row>::const_iterator>,string> executeIterators(map<string,Table> &tables);
 	QueryResult execute(map<string,Table> &tables);
 };
 
@@ -56,3 +56,8 @@ struct InsertQuery : public Query{
 	QueryResult execute(map<string,Table> &tables);
 };
 
+struct DeleteQuery : public Query{
+	vector<WhereClause> where;
+	DeleteQuery(void);
+	QueryResult execute(map<string,Table> &tables);
+};