added better database get api

src/database/database.cpp

@@ -1,6 +1,7 @@
 #include "crow.h"
 #include "utils.hpp"
 #include "database.hpp"
+#include <optional>
 
 using namespace std;
 
@@ -72,18 +73,6 @@ map<string, string> Database::getStrMap(const std::string sql, const Database::Q
     return map;
 }
 
-string Database::getStr(const std::string sql, const Database::QueryData& data){
-    sqlite3_stmt* stmt = bind(sql, data);
-    string str;
-    if (stmt == nullptr)
-        return str; 
-
-    str = reinterpret_cast<const char*>(sqlite3_column_text(stmt, 0));
-    
-    sqlite3_finalize(stmt);
-    return str;
-}
-
 set<string> Database::getStrSet(const string& sql){
     sqlite3_stmt* stmt = prepareStmt(sql);
     set<string> vec;
@@ -99,20 +88,6 @@ set<string> Database::getStrSet(const string& sql){
     return vec;
 }
 
-std::optional<int64_t> Database::getInt(const char* sql) {
-    sqlite3_stmt* stmt = prepareStmt(sql);
-    if (stmt == nullptr)
-        return {}; 
-
-    std::optional<int64_t> id;
-    if (sqlite3_step(stmt) == SQLITE_ROW) {
-        id = sqlite3_column_int64(stmt, 0); 
-    }
-
-    sqlite3_finalize(stmt);
-    return id;
-}
-
 std::optional<int64_t> Database::insert(const char* sql) {
     sqlite3_stmt* stmt = prepareStmt(sql);
     if (stmt == nullptr)

src/database/database.hpp

@@ -21,14 +21,27 @@ public:
     bool exec(const char* sqlQuery);
     bool exec(const std::string& sqlQuery);
 
-    /// returns true if the sql statment returns at least one row 
-    std::optional<int64_t> getInt(const char* sql);
-
     std::optional<int64_t> insert(const char* sql);
 
     std::set<std::string> getStrSet(const std::string& sql);
 
-    std::string getStr(const std::string sql, const QueryData& data);
+    template <typename T>
+    std::optional<T> get(const std::string sql, const QueryData& data){
+        sqlite3_stmt* stmt = bind(sql, data);
+        T ret;
+        if ((stmt == nullptr) || (sqlite3_step(stmt) != SQLITE_ROW))
+            return {}; 
+
+        if constexpr (std::is_same_v<T, int>) {
+            ret = sqlite3_column_int64(stmt, 0); 
+        }
+        else if constexpr (std::is_same_v<T, std::string>){
+            ret = reinterpret_cast<const char*>(sqlite3_column_text(stmt, 0));
+        }
+        
+        sqlite3_finalize(stmt);
+        return ret;
+    }
 
     sqlite3_stmt* bind(const std::string sql, const QueryData& data);