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#pragma once
#include "Driver.h"
#include "Core/Str.h"
namespace sql {
/**
* A single value in a column for the MySQL database.
*
* This class allows converting to and from the MYSQL_BIND structure that represents an
* arbitrary datatype. In particular, this class supports storing the data externally so
* that we can create an array of MYSQL_BIND structures to pass to the mysql C-api.
*
* Values are initialized to a generic NULL value, without a particular type.
*/
class Value {
public:
// Create, and associate with some data. This operation will clear whatever is inside 'data'.
Value(MYSQL_BIND *data);
// Destroy. Frees any allocated memory, and clears the associated data.
~Value();
// Set the value. This also makes the value into the desired type (e.g. for output). For
// dynamic data types (e.g. strings), it is possible to set an "empty" representation
// and populate it later. In these cases, call the version that takes a length parameter
// as appropriate.
void setInt(Long value);
void setUInt(Word value);
void setFloat(Double value);
void setString(Str *value);
void setString(size_t max_length);
void setNull();
// Check contained type.
bool isInt() const;
bool isUInt() const;
bool isFloat() const;
bool isString() const;
bool isNull() const;
// Get the value as a particular type.
Long getInt() const;
Word getUInt() const;
Double getFloat() const;
Str *getString(Engine &e) const;
// Check if truncated. If truncated, return the full size of the data.
size_t isTruncated() const {
if (error)
return dataLength;
else
return 0;
}
private:
// Associated data container.
MYSQL_BIND *data;
// Is the value null?
my_bool nullValue;
// Truncation error?
my_bool error;
// Data length. Only used for strings and other dynamic data structures.
unsigned long dataLength;
// Inline data storage large enough to store an integer. This is so that we can avoid
// some allocations when interoperating with MySQL.
union Data {
Long signedVal;
Word unsignedVal;
Double floatVal;
} localBuffer;
// Clear any data in this value, and re-set into the generic null representation.
void clear();
};
}
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