sql_handler.h

#pragma once
#include <string>

struct CommonSqlHandler {
    virtual void        ExecuteQuery(const std::string &sql) = 0;
    virtual int32_t     ExecuteUpdate(const std::string &sql) = 0;
    virtual bool        Next() = 0;
    virtual size_t      GetFetchSize() = 0;
    virtual size_t      GetRow() = 0;
    virtual std::string EscapeString(const std::string &str) { return str; };
    ~CommonSqlHandler () {}
};

// 需要实现的接口
struct ColumnIndexSqlHandler : public CommonSqlHandler {
    virtual bool        GetBoolean(uint32_t column_index) const = 0;
    virtual long double GetDouble(uint32_t column_index) const = 0;
    virtual int32_t     GetInt(uint32_t column_index) const = 0;
    virtual uint32_t    GetUInt(uint32_t column_index) const = 0;
    virtual int64_t     GetInt64(uint32_t column_index) const = 0;
    virtual uint64_t    GetUInt64(uint32_t column_index) const = 0;
    virtual std::string GetString(uint32_t column_index)  const = 0;
};


// 需要实现的接口
struct ColumnLabelSqlHandler : public CommonSqlHandler {
    virtual bool        GetBoolean(const std::string& column_label) const = 0;
    virtual long double GetDouble(const std::string& column_label) const = 0;
    virtual int32_t     GetInt(const std::string& column_label) const = 0;
    virtual uint32_t    GetUInt(const std::string& column_label) const = 0;
    virtual int64_t     GetInt64(const std::string& column_label) const = 0;
    virtual uint64_t    GetUInt64(const std::string& column_label) const = 0;
    virtual std::string GetString(const std::string& column_label) const = 0;
};