Add StatementPtr - better structure for Statement shared_ptr

Author: Kacperos155

CMakeLists.txt

@@ -109,6 +109,7 @@ set(SQLITECPP_SRC
  ${PROJECT_SOURCE_DIR}/src/Savepoint.cpp
  ${PROJECT_SOURCE_DIR}/src/Statement.cpp
  ${PROJECT_SOURCE_DIR}/src/StatementExecutor.cpp
+ ${PROJECT_SOURCE_DIR}/src/StatementPtr.cpp
  ${PROJECT_SOURCE_DIR}/src/Transaction.cpp
 )
 source_group(src FILES ${SQLITECPP_SRC})
@@ -125,6 +126,7 @@ set(SQLITECPP_INC
  ${PROJECT_SOURCE_DIR}/include/SQLiteCpp/Savepoint.h
  ${PROJECT_SOURCE_DIR}/include/SQLiteCpp/Statement.h
  ${PROJECT_SOURCE_DIR}/include/SQLiteCpp/StatementExecutor.h
+ ${PROJECT_SOURCE_DIR}/include/SQLiteCpp/StatementPtr.h
  ${PROJECT_SOURCE_DIR}/include/SQLiteCpp/Transaction.h
  ${PROJECT_SOURCE_DIR}/include/SQLiteCpp/VariadicBind.h
  ${PROJECT_SOURCE_DIR}/include/SQLiteCpp/ExecuteMany.h

include/SQLiteCpp/Column.h

@@ -10,14 +10,12 @@
  */
 #pragma once
 
-#include <SQLiteCpp/Statement.h>
-#include <SQLiteCpp/Exception.h>
+#include <SQLiteCpp/StatementPtr.h>
 
+#include <ostream>
 #include <string>
 #include <memory>
 
-// Forward declarations to avoid inclusion of <sqlite3.h> in a header
-struct sqlite3_stmt;
 
 namespace SQLite
 {
@@ -55,7 +53,7 @@ class Column
      * 
      * @throws Exception is thrown in case of error, then the Column object is NOT constructed.
      */
-    explicit Column(const StatementExecutor::TStatementPtr& aStmtPtr, int aIndex);
+    explicit Column(const StatementPtr::TStatementPtr& aStmtPtr, int aIndex);
 
     /**
      * @brief Return a pointer to the named assigned to this result column (potentially aliased)
@@ -226,7 +224,7 @@ class Column
     }
 
 private:
-    StatementExecutor::TStatementPtr  mStmtPtr;  ///< Shared Pointer to the prepared SQLite Statement Object
+    StatementPtr::TStatementPtr mStmtPtr;  ///< Shared Pointer to the prepared SQLite Statement Object
     int                         mIndex;    ///< Index of the column in the row of result, starting at 0
 };
 
@@ -242,25 +240,5 @@ class Column
  */
 std::ostream& operator<<(std::ostream& aStream, const Column& aColumn);
 
-#if __cplusplus >= 201402L || (defined(_MSC_VER) && _MSC_VER >= 1900) // c++14: Visual Studio 2015
-
-// Create an instance of T from the first N columns, see declaration in Statement.h for full details
-template<typename T, int N>
-T Statement::getColumns()
-{
-    checkRow();
-    checkIndex(N - 1);
-    return getColumns<T>(std::make_integer_sequence<int, N>{});
-}
-
-// Helper function called by getColums<typename T, int N>
-template<typename T, const int... Is>
-T Statement::getColumns(const std::integer_sequence<int, Is...>)
-{
-    return T{ Column(getStatement(), Is)... };
-}
-
-#endif
-
 
 }  // namespace SQLite

include/SQLiteCpp/Database.h

@@ -10,6 +10,7 @@
  */
 #pragma once
 
+#include <SQLiteCpp/Exception.h>
 #include <SQLiteCpp/Column.h>
 
 // c++17: MinGW GCC version > 8

include/SQLiteCpp/Row.h

@@ -11,13 +11,11 @@
  */
 #pragma once
 
-//#include <SQLiteCpp/RowExecutor.h>
+#include <SQLiteCpp/StatementPtr.h>
 
 #include <memory>
 #include <string>
 
-// Forward declaration to avoid inclusion of <sqlite3.h> in a header
-struct sqlite3_stmt;
 
 namespace SQLite
 {
@@ -27,11 +25,8 @@ namespace SQLite
 */
 class Row
 {
-    /// Weak pointer to SQLite Prepared Statement Object
-    using TStatementWeakPtr = std::weak_ptr<sqlite3_stmt>;
-
 public:
-    Row(TStatementWeakPtr apRow, std::size_t aID);
+    Row(TRowWeakPtr apStatement, std::size_t aID);
 
     std::size_t getRowNumber() const
     {
@@ -58,7 +53,7 @@ class Row
     const char* getText(uint32_t aColumnID) const noexcept;
 
 private:
-    TStatementWeakPtr mpRow;
+    TRowWeakPtr mpStatement;
     std::size_t ID;
 };
 

include/SQLiteCpp/Statement.h

@@ -59,18 +59,13 @@ class Statement : public StatementExecutor
      */
     Statement(const Database& aDatabase, const std::string& aQuery);
 
-    /**
-     * @brief Move an SQLite statement.
-     *
-     * @param[in] aStatement    Statement to move
-     */
-    Statement(Statement&& aStatement) noexcept = default;
-    Statement& operator=(Statement&& aStatement) noexcept = default;
-
     // Statement is non-copyable
     Statement(const Statement&) = delete;
     Statement& operator=(const Statement&) = delete;
 
+    Statement(Statement&& aStatement) = default;
+    Statement& operator=(Statement&& aStatement) = default;
+
     /// Finalize and unregister the SQL query from the SQLite Database Connection.
     /// The finalization will be done by the destructor of the last shared pointer
     ~Statement() = default;
@@ -440,15 +435,27 @@ class Statement : public StatementExecutor
      * @note Requires std=C++14
      */
     template<typename T, int N>
-    T       getColumns();
+    T getColumns()
+    {
+        checkRow();
+        checkIndex(N - 1);
+        return getColumns<T>(std::make_integer_sequence<int, N>{});
+    }
 
 private:
     /**
     * @brief Helper function used by getColumns<typename T, int N> to expand an integer_sequence used to generate
     *        the required Column objects
+    * 
+    * @note Requires std=C++14
+    * 
+    * @return Column object for each column in statement
     */
     template<typename T, const int... Is>
-    T       getColumns(const std::integer_sequence<int, Is...>);
+    T getColumns(const std::integer_sequence<int, Is...>)
+    {
+        return T{ Column(getStatement(), Is)... };
+    }
 
 public:
 #endif

include/SQLiteCpp/StatementExecutor.h

@@ -3,23 +3,21 @@
  * @ingroup SQLiteCpp
  * @brief   Step executor for SQLite prepared Statement Object
  *
- * Copyright (c) 2015 Shibao HONG (shibaohong@outlook.com)
- * Copyright (c) 2015-2021 Sebastien Rombauts (sebastien.rombauts@gmail.com)
+ * Copyright (c) 2012-2021 Sebastien Rombauts (sebastien.rombauts@gmail.com)
  *
  * Distributed under the MIT License (MIT) (See accompanying file LICENSE.txt
  * or copy at http://opensource.org/licenses/MIT)
  */
 #pragma once
 
+#include <SQLiteCpp/StatementPtr.h>
 #include <SQLiteCpp/Row.h>
 #include <SQLiteCpp/Exception.h>
 
 #include <memory>
 #include <string>
 #include <map>
 
-// Forward declaration to avoid inclusion of <sqlite3.h> in a header
-struct sqlite3_stmt;
 
 namespace SQLite
 {
@@ -44,24 +42,13 @@ extern const int OK; ///< SQLITE_OK
 class StatementExecutor
 {
 public:
-    /// Shared pointer to SQLite Prepared Statement Object
-    using TStatementPtr = std::shared_ptr<sqlite3_stmt>;
-
-    /// Weak pointer to SQLite Prepared Statement Object
-    using TStatementWeakPtr = std::weak_ptr<sqlite3_stmt>;
-
-    /// Shared pointer to SQLite StatementExecutor
-    using TRowPtr = std::shared_ptr<StatementExecutor>;
-
-    /// Weak pointer to SQLite StatementExecutor
-    using TRowWeakPtr = std::weak_ptr<StatementExecutor>;
-
     /// Type to store columns names and indexes
     using TColumnsMap = std::map<std::string, int, std::less<>>;
 
     StatementExecutor(const StatementExecutor&) = delete;
-    StatementExecutor(StatementExecutor&&) = default;
     StatementExecutor& operator=(const StatementExecutor&) = delete;
+
+    StatementExecutor(StatementExecutor&&) = default;
     StatementExecutor& operator=(StatementExecutor&&) = default;
 
     /// Reset the statement to make it ready for a new execution. Throws an exception on error.
@@ -180,8 +167,8 @@ class StatementExecutor
         using difference_type = std::ptrdiff_t;
 
         RowIterator() = default;
-        RowIterator(TStatementWeakPtr apStatement, TRowWeakPtr apRow, uint16_t aID) :
-            mpStatement(apStatement), mpRow(apRow), mID(aID), mRow(apStatement, aID) {}
+        RowIterator(TRowWeakPtr apStatement, uint16_t aID) :
+            mpStatement(apStatement), mID(aID), mRow(apStatement, aID) {}
 
         reference operator*() const
         {
@@ -216,8 +203,7 @@ class StatementExecutor
         /// Executing next statement step
         void advance() noexcept;
 
-        TStatementWeakPtr   mpStatement{};  //!< Weak pointer to SQLite Statement Object
-        TRowWeakPtr         mpRow{};        //!< Weak pointer to StatementExecutor Object
+        TRowWeakPtr         mpStatement{};  //!< Weak pointer to prepared Statement Object
         uint16_t            mID{};          //!< Current row number
 
         /// Internal row object storage
@@ -256,9 +242,9 @@ class StatementExecutor
      *
      * @return raw pointer to Statement Object
      */
-    TStatementPtr getStatement() const noexcept
+    StatementPtr::TStatementPtr getStatement() const noexcept
     {
-        return mpStatement;
+        return mpStatement->mpStatement;
     }
 
     /**
@@ -277,7 +263,7 @@ class StatementExecutor
      */
     TRowWeakPtr getExecutorWeakPtr() const
     {
-        return mpRowExecutor;
+        return mpStatement;
     }
 
     ////////////////////////////////////////////////////////////////////////////
@@ -291,7 +277,7 @@ class StatementExecutor
     {
         if (SQLite::OK != aRet)
         {
-            throw SQLite::Exception(mpSQLite, aRet);
+            throw SQLite::Exception(mpStatement->mpConnection, aRet);
         }
     }
 
@@ -318,18 +304,17 @@ class StatementExecutor
     }
 
 private:
-    ///  Create prepared SQLite Statement Object
-    void prepareStatement(const std::string& aQuery);
-
     ///  Get column number and create map with columns names
     void createColumnInfo();
 
-    sqlite3*        mpSQLite{};     //!< Pointer to SQLite Database Connection Handle
-    TStatementPtr   mpStatement{};  //!< Shared Pointer to the prepared SQLite Statement Object
+    // xD
+    bool checkReturnCode(int aReturnCode) const;
+    // xD
+    bool checkReturnCode(int aReturnCode, int aErrorCode) const;
 
     /// Shared Pointer to this object.
     /// Allows RowIterator to execute next step
-    TRowPtr mpRowExecutor{};
+    TRowPtr mpStatement{};
 
     int     mColumnCount = 0;   //!< Number of columns in the result of the prepared statement
     bool    mbHasRow = false;   //!< true when a row has been fetched with executeStep()

include/SQLiteCpp/StatementPtr.h

@@ -0,0 +1,75 @@
+/**
+ * @file    StatementPtr.h
+ * @ingroup SQLiteCpp
+ * @brief   Pointer for prepared SQLite Statement Object
+ *
+ * Copyright (c) 2022 Sebastien Rombauts (sebastien.rombauts@gmail.com)
+ *
+ * Distributed under the MIT License (MIT) (See accompanying file LICENSE.txt
+ * or copy at http://opensource.org/licenses/MIT)
+ */
+#pragma once
+
+#include <memory>
+#include <string>
+
+// Forward declaration to avoid inclusion of <sqlite3.h> in a header
+struct sqlite3;
+struct sqlite3_stmt;
+
+namespace SQLite
+{
+
+
+/**
+* @brief Container for SQLite Statement pointer.
+*
+* You should never create this object unless you are expanding SQLiteCPP API.
+*/
+struct StatementPtr
+{
+    /**
+    * @brief Don't create this object unless you are expanding SQLiteCPP API.
+    * 
+    * @param[in] apSQLite  the SQLite Database Connection
+    * @param[in] aQuery    an UTF-8 encoded query string
+    *
+    * @throws Exception is thrown in case of error, then the StatementPtr object is NOT constructed.
+    */
+    StatementPtr(sqlite3* apSQLite, const std::string& aQuery);
+
+    /// Shared pointer to SQLite prepared Statement Object
+    using TStatementPtr = std::shared_ptr<sqlite3_stmt>;
+
+    sqlite3* const      mpConnection;       //!< Pointer to SQLite Database Connection Handle
+    TStatementPtr const mpStatement;        //!< Shared Pointer to the prepared SQLite Statement Object
+    std::size_t         mCurrentStep = 0;   //!< Current step of prepared Statement Object
+
+    /// Resets SQLite Statement Object
+    int reset() noexcept;
+
+    /// Execute next step of SQLite Statement Object
+    int step() noexcept;
+
+    /**
+    * @brief Returns pointer to prepared SQLite Statement Object.
+    * Use this ONLY on sqlite3 function!
+    * 
+    * @return Pointer to SQLite Statement Object
+    */
+    sqlite3_stmt* getPreparedStatement() const;
+
+private:
+    /// Create prepared SQLite Statement Object
+    TStatementPtr prepareStatement(sqlite3* apConnection, const std::string& aQuery) const;
+};
+
+
+/// Shared pointer to SQLite StatementPtr
+using TRowPtr = std::shared_ptr<StatementPtr>;
+
+/// Weak pointer to SQLite StatementPtr
+using TRowWeakPtr = std::weak_ptr<StatementPtr>;
+
+
+}  // namespace SQLite