create table as

row.h

@@ -10,7 +10,7 @@ namespace usql {
 
     struct ColValue {
 
-	virtual bool isNull() { return false; };;;;
+	virtual bool isNull() { return false; };
 
 	virtual int integerValue() { throw Exception("Not supported"); };
 
@@ -80,22 +80,20 @@ namespace usql {
 
     public:
 	Row(int cols_count);
-
 	Row(const Row &other);
 
 	Row &operator=(Row other);
 
+	void setColumnNull(int col_index);
 	void setColumnValue(int col_index, int value);
-
 	void setColumnValue(int col_index, double value);
-
 	void setColumnValue(int col_index, const std::string &value);
 
 	ColValue &operator[](int i) {
 		return *m_columns[i];
 	}
 
-	ColValue *ithColumn(int i) {
+	ColValue * ithColumn(int i) const {
 		return m_columns[i].get();
 	}