minimum-viable MySQL connector

src/lib/dtree.h

@@ -49,6 +49,7 @@ struct DTree {
 
 	string 	_string;
 	f64 	_float;
+	s64 	_array_index;
 	bool	_bool;
 	void*	_ptr;
 	std::map<string, DTree> _map;
@@ -88,7 +89,7 @@ struct DTree {
 				return(_bool ? "(true)" : "(false)");
 				break;
 			case('M'):
-				return("(array)");
+				return("");
 				break;
 			case('P'):
 				return(std::to_string((u64)_ptr));
@@ -140,37 +141,48 @@ struct DTree {
 		}
 	}
 
+	void set_type(char t)
+	{
+		if(type != t)
+		{
+			type = t;
+			switch(type)
+			{
+				case('M'):
+					_map.clear();
+					_array_index = 0;
+					break;
+			}
+		}
+	}
+
 	void set(string s)
 	{
-		if(type == 'M') _map.clear();
-		type = 'S';
+		set_type('S');
 		_string = s;
 	}
 
 	void set(void* p)
 	{
-		if(type == 'M') _map.clear();
-		type = 'P';
+		set_type('P');
 		_ptr = p;
 	}
 
 	void set(f64 f)
 	{
-		if(type == 'M') _map.clear();
-		type = 'F';
+		set_type('F');
 		_float = f;
 	}
 
 	void set_bool(bool b)
 	{
-		if(type == 'M') _map.clear();
-		type = 'B';
+		set_type('B');
 		_bool = b;
 	}
 
 	void set(DTree source)
 	{
-		type = source.type;
+		set_type(source.type);
 		switch(type)
 		{
 			case('S'):
@@ -193,8 +205,7 @@ struct DTree {
 
 	void set(StringMap source)
 	{
-		type = 'M';
-		_map.clear();
+		set_type('M');
 		for (auto it = source.begin(); it != source.end(); ++it)
 		{
 			(*this)[it->first] = it->second;
@@ -203,12 +214,12 @@ struct DTree {
 
 	DTree* key(string s)
 	{
-		type = 'M';
+		set_type('M');
 		return(&_map[s]);
 	}
 
 	DTree& operator [] (string s) {
-		type = 'M';
+		set_type('M');
 		return(_map[s]);
 	}
 
@@ -218,15 +229,31 @@ struct DTree {
 	void operator = (DTree v) { set(v); }
 	void operator = (StringMap v) { set(v); }
 
+	void push(DTree& child)
+	{
+		set_type('M');
+		_map[std::to_string(_array_index)] = child;
+		_array_index += 1;
+	}
+
+	DTree pop()
+	{
+		set_type('M');
+		auto last = _map.rbegin();
+		DTree result = last->second;
+		_map.erase(last->first);
+		return(result);
+	}
+
 	void remove(string s)
 	{
-		type = 'M';
+		set_type('M');
 		_map.erase(s);
 	}
 
 	void clear()
 	{
-		type = 'M';
+		set_type('M');
 		_map.clear();
 	}
 

src/lib/mysql-connector.cpp

@@ -67,19 +67,118 @@ string MySQL::escape(string raw, char quote_char)
 	return(result);
 }
 
-bool MySQL::query(string query)
+DTree field_to_dtree_node(char* data_ptr, MySQLFieldInfo field_info, u32 len)
 {
-	auto res = mysql_query((MYSQL*)connection, query.c_str());
-	return(true);
+	DTree result;
+	switch(field_info.type)
+	{
+		case(MYSQL_TYPE_TINY):
+			result.set(atoll(data_ptr));
+			break;
+		case(MYSQL_TYPE_SHORT):
+			result.set(atoll(data_ptr));
+			break;
+		case(MYSQL_TYPE_LONG):
+			result.set(atoll(data_ptr));
+			break;
+		case(MYSQL_TYPE_INT24):
+			result.set(atoll(data_ptr));
+			break;
+		case(MYSQL_TYPE_LONGLONG):
+			result.set(atoll(data_ptr));
+			break;
+		case(MYSQL_TYPE_FLOAT):
+			result.set(atof(data_ptr));
+			break;
+		case(MYSQL_TYPE_DOUBLE):
+			result.set(atof(data_ptr));
+			break;
+		case(MYSQL_TYPE_NULL):
+			break;
+		default:
+			string s;
+			s.assign(data_ptr);
+			result.set(s);
+			break;
+	}
+	return(result);
 }
 
-bool MySQL::query(string query, StringMap params)
+DTree MySQL::get_pending_result()
 {
-	auto res = mysql_query(
-		(MYSQL*)connection,
-		parse_query_parameters(query, params).c_str()
-	);
-	return(true);
+	DTree result_data;
+	// based on: https://dev.mysql.com/doc/c-api/5.7/en/mysql-field-count.html
+	MYSQL_RES *result;
+	result = mysql_store_result((MYSQL*)connection);
+	insert_id = mysql_insert_id((MYSQL*)connection);
+	//statement_info.assign(mysql_info((MYSQL*)connection));
+    if (result)  // there are rows
+    {
+        field_count = mysql_num_fields(result);
+        row_count = mysql_num_rows(result);
+
+		field_info.clear();
+		unsigned int i;
+		MYSQL_FIELD *fields;
+		fields = mysql_fetch_fields(result);
+		for(i = 0; i < field_count; i++)
+		{
+			MySQLFieldInfo fi;
+			if(fields[i].name) fi.name.assign(fields[i].name);
+			if(fields[i].table) fi.table.assign(fields[i].table);
+			if(fields[i].db) fi.db.assign(fields[i].db);
+			fi.length = (fields[i].length);
+			if(fields[i].def) fi.def.assign(fields[i].def);
+			fi.max_length = (fields[i].max_length);
+			fi.flags = (fields[i].flags);
+			fi.type = (fields[i].type);
+			field_info.push_back(fi);
+		}
+
+        MYSQL_ROW row;
+        while ((row = mysql_fetch_row(result)))
+		{
+			DTree row_data;
+			auto lengths = mysql_fetch_lengths(result);
+			for(i = 0; i < field_count; i++)
+			{
+				row_data[field_info[i].name] = field_to_dtree_node(row[i], field_info[i], lengths[i]);
+			}
+			result_data.push(row_data);
+		}
+
+        mysql_free_result(result);
+    }
+    else  // mysql_store_result() returned nothing; should it have?
+    {
+        if(mysql_field_count((MYSQL*)connection) == 0)
+        {
+            // query does not return data
+            // (it was not a SELECT)
+            affected_rows = mysql_affected_rows((MYSQL*)connection);
+        }
+        else // mysql_store_result() should have returned data
+        {
+			// error
+        }
+    }
+    return(result_data);
+}
+
+DTree MySQL::query(string q)
+{
+	_preload_next_error_code = mysql_query((MYSQL*)connection, q.c_str());
+	DTree result;
+	if(_preload_next_error_code == 0)
+		result = get_pending_result();
+	return(result);
+}
+
+DTree MySQL::query(string q, StringMap params)
+{
+	return(query(
+		parse_query_parameters(q, params).c_str()
+	));
 }
 
 string MySQL::parse_query_parameters(string query, StringMap map)
@@ -144,6 +243,31 @@ void MySQL::disconnect()
 
 string MySQL::error()
 {
+	if(_preload_next_error_code)
+	{
+		string p = "Unknown error";
+		switch(_preload_next_error_code)
+		{
+			case(CR_COMMANDS_OUT_OF_SYNC):
+				p = "Commands out of sync";
+				break;
+			case(CR_SERVER_GONE_ERROR):
+				p = "Server connection error";
+				break;
+			case(CR_SERVER_LOST):
+				p = "Server hung up";
+				break;
+			case(CR_OUT_OF_MEMORY):
+				p = "Out of memory";
+				break;
+			default:
+			case(CR_UNKNOWN_ERROR):
+				p = "Unknown server error";
+				break;
+		}
+		_preload_next_error_code = 0;
+		return(p);
+	}
 	const char* res = mysql_error((MYSQL*)connection);
 	if(res)
 	{

src/lib/mysql-connector.h

@@ -1,14 +1,33 @@
+struct MySQLFieldInfo {
+	string name;
+	string table;
+	string db;
+	u64 length;
+	string def;
+	u64 max_length;
+	u64 flags;
+	u32 type;
+};
 
 struct MySQL {
 
-	void* connection;
+	void* connection = 0;
+	u32 _preload_next_error_code = 0;
+	u32 affected_rows = 0;
+	u32 field_count = 0;
+	u32 row_count = 0;
+	u64 insert_id = 0;
+	string statement_info = "";
+
+	std::vector<MySQLFieldInfo> field_info;
 
 	bool connect(string host = "localhost", string username = "root", string password = "");
 	void disconnect();
 	string error();
 	string escape(string raw, char quote_char = '\'');
 	string parse_query_parameters(string query, StringMap m);
-	bool query(string query);
-	bool query(string query, StringMap params);
-	
+	DTree query(string q);
+	DTree query(string q, StringMap params);
+	DTree get_pending_result();
+
 };

test/mysql.uce

@@ -19,14 +19,25 @@ RENDER()
 			params["val"] = "Dubious\\Value'Name\nwith;breaks";
 
 			MySQL con;
-			if(con.connect("localhost", "root", "q831b197f"))
+			if(con.connect("localhost", "root", ""))
 			{
 				echo("connection established\n");
 				echo("error: "+con.error()+"\n");
 				echo("quotation test: "+con.escape("‘\"' or 1=1;–.")+"\n");
 				echo("query parse: "+con.parse_query_parameters(query, params)+"\n");
+				echo(var_dump(con.query("SHOW DATABASES")));
+				con.query("USE mysql");
+
+		?></pre>
+
+		SELECT * FROM user table
+
+		<pre><?
+
+				echo(var_dump(con.query("SELECT * FROM user")));
+
 			}
-			
+
 		?></pre>
 
 		<label>CGI Params</label>