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Add bindNoCopy methods to allow binding std::string with SQLITE_STATIC.
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Should be safe, as long as you can guarantee the std::string exists while executing the query.

Added an accessor to Column that returns a std::string, that can handle BLOB or TEXT values that contain null-bytes.

Also more binding & Column cast support for uint32_t - fixes ambiguous overload errors when using unsigned-integer types.
Note that I didn't use uint64_t, because unsigned 64-bit integers doesn't fit into SQLite (except for using int64_t and dealing with overflow with custom functions).

Added a C++11 move constructor to Statement, to allow storing it inside STL containers (eg. vector).
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@DouglasHeriot
DouglasHeriot committed Jun 25, 2016
1 parent 50501a4 commit d1fc9c3
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Showing 4 changed files with 189 additions and 21 deletions.
29 changes: 24 additions & 5 deletions include/SQLiteCpp/Column.h
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Original file line number Diff line number Diff line change
Expand Up @@ -99,7 +99,14 @@ class Column
* thus you must copy it before using it beyond its scope (to a std::string for instance).
*/
const void* getBlob() const noexcept; // nothrow

/**
* @brief Return a std::string for a TEXT or BLOB column.
*
* Note this correctly handles strings that contain null bytes.
*
*/
std::string getString() const noexcept; // nothrow

/**
* @brief Return the type of the value of the column
*
Expand Down Expand Up @@ -158,6 +165,11 @@ class Column
{
return getInt();
}
/// @brief Inline cast operator to 32bits unsigned integer
inline operator uint32_t() const
{
return static_cast<uint32_t>(getInt64());
}
/// @brief Inline cast operator to 64bits integer
inline operator sqlite3_int64() const
{
Expand Down Expand Up @@ -186,19 +198,26 @@ class Column
{
return getBlob();
}

#if !(defined(_MSC_VER) && _MSC_VER < 1900)
// NOTE : the following is required by GCC and Clang to cast a Column result in a std::string
// (error: conversion from ‘SQLite::Column’ to non-scalar type ‘std::string {aka std::basic_string<char>}’)
// but is not working under Microsoft Visual Studio 2010, 2012 and 2013
// (error C2440: 'initializing' : cannot convert from 'SQLite::Column' to 'std::basic_string<_Elem,_Traits,_Ax>'
// [...] constructor overload resolution was ambiguous)
/// Inline cast operator to std::string
inline operator const std::string() const
/**
* @brief Inline cast operator to std::string
*
* Handles BLOB or TEXT, which may contain null bytes within
*
* @see getString
*/
inline operator std::string() const
{
return getText();
return getString();
}
#endif

// NOTE : the following is required by GCC and Clang to cast a Column result in a long/int64_t
/// @brief Inline cast operator to long as 64bits integer
inline operator long() const
Expand Down
90 changes: 81 additions & 9 deletions include/SQLiteCpp/Statement.h
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Original file line number Diff line number Diff line change
Expand Up @@ -67,6 +67,17 @@ class Statement
*/
Statement(Database& aDatabase, const std::string& aQuery);

// Require C++11
#if ( __cplusplus>= 201103L) || ( defined(_MSC_VER) && (_MSC_VER >= 1900) )
#define Statement_CAN_MOVE 1
/**
* @breif Move Constructor
*
* (Allows inserting into STL containers that may need to move memory when growing.)
*/
Statement(Statement &&other);
#endif

/**
* @brief Finalize and unregister the SQL query from the SQLite Database Connection.
*/
Expand Down Expand Up @@ -105,21 +116,33 @@ class Statement
/**
* @brief Bind an int value to a parameter "?", "?NNN", ":VVV", "@VVV" or "$VVV" in the SQL prepared statement (aIndex >= 1)
*/
void bind(const int aIndex, const int& aValue);
void bind(const int aIndex, const int aValue);
/**
* @brief Bind a 64bits int value to a parameter "?", "?NNN", ":VVV", "@VVV" or "$VVV" in the SQL prepared statement (aIndex >= 1)
*/
void bind(const int aIndex, const sqlite3_int64& aValue);
void bind(const int aIndex, const sqlite3_int64 aValue);
/**
* @brief Bind a 32bits unsigned int value to a parameter "?", "?NNN", ":VVV", "@VVV" or "$VVV" in the SQL prepared statement (aIndex >= 1)
*/
void bind(const int aIndex, const uint32_t aValue);
/**
* @brief Bind a double (64bits float) value to a parameter "?", "?NNN", ":VVV", "@VVV" or "$VVV" in the SQL prepared statement (aIndex >= 1)
*/
void bind(const int aIndex, const double& aValue);
void bind(const int aIndex, const double aValue);
/**
* @brief Bind a string value to a parameter "?", "?NNN", ":VVV", "@VVV" or "$VVV" in the SQL prepared statement (aIndex >= 1)
*
* @note This uses the SQLITE_TRANSIENT flag, making a copy of the data, for SQLite internal use
*/
void bind(const int aIndex, const std::string& aValue);

/**
* @brief Bind a string value to a parameter "?", "?NNN", ":VVV", "@VVV" or "$VVV" in the SQL prepared statement (aIndex >= 1)
*
* @note This uses the SQLITE_STATIC flag, NOT making a copy of the data. It must exist while executing the statement.
*/
void bindNoCopy(const int aIndex, const std::string& aValue);

/**
* @brief Bind a text value to a parameter "?", "?NNN", ":VVV", "@VVV" or "$VVV" in the SQL prepared statement (aIndex >= 1)
*
Expand All @@ -132,6 +155,14 @@ class Statement
* @note This uses the SQLITE_TRANSIENT flag, making a copy of the data, for SQLite internal use
*/
void bind(const int aIndex, const void* apValue, const int aSize);

/**
* @brief Bind a binary blob value to a parameter "?", "?NNN", ":VVV", "@VVV" or "$VVV" in the SQL prepared statement (aIndex >= 1)
*
* @note This uses the SQLITE_STATIC flag, NOT making a copy of the data. It must exist while executing the statement.
*/
void bindNoCopy(const int aIndex, const void* apValue, const int aSize);

/**
* @brief Bind a NULL value to a parameter "?", "?NNN", ":VVV", "@VVV" or "$VVV" in the SQL prepared statement (aIndex >= 1)
*/
Expand All @@ -140,21 +171,31 @@ class Statement
/**
* @brief Bind an int value to a named parameter "?NNN", ":VVV", "@VVV" or "$VVV" in the SQL prepared statement (aIndex >= 1)
*/
void bind(const char* apName, const int& aValue);
void bind(const char* apName, const int aValue);
/**
* @brief Bind a 64bits int value to a named parameter "?NNN", ":VVV", "@VVV" or "$VVV" in the SQL prepared statement (aIndex >= 1)
*/
void bind(const char* apName, const sqlite3_int64& aValue);
void bind(const char* apName, const sqlite3_int64 aValue);
/**
* @brief Bind a 32bits unsigned int value to a named parameter "?NNN", ":VVV", "@VVV" or "$VVV" in the SQL prepared statement (aIndex >= 1)
*/
void bind(const char* apName, const uint32_t aValue);
/**
* @brief Bind a double (64bits float) value to a named parameter "?NNN", ":VVV", "@VVV" or "$VVV" in the SQL prepared statement (aIndex >= 1)
*/
void bind(const char* apName, const double& aValue);
void bind(const char* apName, const double aValue);
/**
* @brief Bind a string value to a named parameter "?NNN", ":VVV", "@VVV" or "$VVV" in the SQL prepared statement (aIndex >= 1)
*
* @note This uses the SQLITE_TRANSIENT flag, making a copy of the data, for SQLite internal use
*/
void bind(const char* apName, const std::string& aValue);
/**
* @brief Bind a string value to a named parameter "?NNN", ":VVV", "@VVV" or "$VVV" in the SQL prepared statement (aIndex >= 1)
*
* @note This uses the SQLITE_STATIC flag, NOT making a copy of the data.
*/
void bindNoCopy(const char* apName, const std::string& aValue);
/**
* @brief Bind a text value to a named parameter "?NNN", ":VVV", "@VVV" or "$VVV" in the SQL prepared statement (aIndex >= 1)
*
Expand All @@ -167,6 +208,12 @@ class Statement
* @note This uses the SQLITE_TRANSIENT flag, making a copy of the data, for SQLite internal use
*/
void bind(const char* apName, const void* apValue, const int aSize);
/**
* @brief Bind a binary blob value to a named parameter "?NNN", ":VVV", "@VVV" or "$VVV" in the SQL prepared statement (aIndex >= 1)
*
* @note This uses the SQLITE_STATIC flag, making a copy of the data.
*/
void bindNoCopy(const char* apName, const void* apValue, const int aSize);
/**
* @brief Bind a NULL value to a named parameter "?NNN", ":VVV", "@VVV" or "$VVV" in the SQL prepared statement (aIndex >= 1)
*/
Expand All @@ -176,21 +223,28 @@ class Statement
/**
* @brief Bind an int value to a named parameter "?NNN", ":VVV", "@VVV" or "$VVV" in the SQL prepared statement (aIndex >= 1)
*/
inline void bind(const std::string& aName, const int& aValue)
inline void bind(const std::string& aName, const int aValue)
{
bind(aName.c_str(), aValue);
}
/**
* @brief Bind a 64bits int value to a named parameter "?NNN", ":VVV", "@VVV" or "$VVV" in the SQL prepared statement (aIndex >= 1)
*/
inline void bind(const std::string& aName, const sqlite3_int64& aValue)
inline void bind(const std::string& aName, const sqlite3_int64 aValue)
{
bind(aName.c_str(), aValue);
}
/**
* @brief Bind a 32bits unsigned int value to a named parameter "?NNN", ":VVV", "@VVV" or "$VVV" in the SQL prepared statement (aIndex >= 1)
*/
inline void bind(const std::string& aName, const uint32_t aValue)
{
bind(aName.c_str(), aValue);
}
/**
* @brief Bind a double (64bits float) value to a named parameter "?NNN", ":VVV", "@VVV" or "$VVV" in the SQL prepared statement (aIndex >= 1)
*/
inline void bind(const std::string& aName, const double& aValue)
inline void bind(const std::string& aName, const double aValue)
{
bind(aName.c_str(), aValue);
}
Expand All @@ -203,6 +257,15 @@ class Statement
{
bind(aName.c_str(), aValue);
}
/**
* @brief Bind a string value to a named parameter "?NNN", ":VVV", "@VVV" or "$VVV" in the SQL prepared statement (aIndex >= 1)
*
* @note This uses the SQLITE_STATIC flag, NOT making a copy of the data.
*/
inline void bindNoCopy(const std::string& aName, const std::string& aValue)
{
bindNoCopy(aName.c_str(), aValue);
}
/**
* @brief Bind a text value to a named parameter "?NNN", ":VVV", "@VVV" or "$VVV" in the SQL prepared statement (aIndex >= 1)
*
Expand All @@ -221,6 +284,15 @@ class Statement
{
bind(aName.c_str(), apValue, aSize);
}
/**
* @brief Bind a binary blob value to a named parameter "?NNN", ":VVV", "@VVV" or "$VVV" in the SQL prepared statement (aIndex >= 1)
*
* @note This uses the SQLITE_STATIC flag, NOT making a copy of the data.
*/
inline void bindNoCopy(const std::string& aName, const void* apValue, const int aSize)
{
bindNoCopy(aName.c_str(), apValue, aSize);
}
/**
* @brief Bind a NULL value to a named parameter "?NNN", ":VVV", "@VVV" or "$VVV" in the SQL prepared statement (aIndex >= 1)
*/
Expand Down
15 changes: 14 additions & 1 deletion src/Column.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -69,12 +69,25 @@ const char* Column::getText(const char* apDefaultValue /* = "" */) const noexcep
return (pText?pText:apDefaultValue);
}

// Return a pointer to the text value (NULL terminated string) of the column specified by its index starting at 0
// Return a pointer to the blob value (*not* NULL terminated) of the column specified by its index starting at 0
const void* Column::getBlob() const noexcept // nothrow
{
return sqlite3_column_blob(mStmtPtr, mIndex);
}

// Return a std::string to a TEXT or BLOB column
std::string Column::getString() const noexcept // nothrow
{
// Note: using sqlite3_column_blob and not sqlite3_column_text
// - no need for sqlite3_column_text to add a \0 on the end, as we're getting the bytes length directly
const char *data = static_cast<const char *>(sqlite3_column_blob(mStmtPtr, mIndex));

// Note: C++ order of argument evaluation is unspecified, so not calling _blob and _bytes both directly in std::string constructor
// SQLite docs: "The safest policy is to invoke… sqlite3_column_blob() followed by sqlite3_column_bytes()"
// Note: std::string is ok to pass nullptr as first arg, if length is 0
return std::string(data, sqlite3_column_bytes(mStmtPtr, mIndex));
}

// Return the type of the value of the column
int Column::getType() const noexcept // nothrow
{
Expand Down
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