用 C++ 封装一层 MySQL 接口，再通过 Lua 桥接函数暴露给脚本层调用。
SQLInterface.cpp
下面是 C++ 封装类及对应的 Lua 桥接函数实现。
#include "mysql/mysql.h"
#pragma comment(lib,"mysql/libmysql.lib")
class SQLInterface
{
public:
SQLInterface()
{
this->res = nullptr;
this->mysql = nullptr;
cout << __FUNCTION__ << endl;
}
~SQLInterface()
{
cout << __FUNCTION__ << endl;
}
bool connect(string user, string pwd, string host, string db, int port)
{
mysql = new MYSQL;
MYSQL_RES *result;
MYSQL_ROW sql_row;
int res;
mysql_init(mysql);
// if (!mysql)return false;
if (!mysql_real_connect(mysql, host.c_str(), user.c_str(), pwd.c_str(), db.c_str(), port, NULL, 0))
{
return false;
}
return true;
}
bool exec(string sql)
{
if (!mysql)return false;
int res11 = mysql_query(this->mysql, sql.c_str());//查询
if (!res11)
{
MYSQL_RES * result = mysql_store_result(mysql);
if (result)
{
this->res = result;
}
}
else
{
cout << "query sql failed!" << endl;
}
return true;
}
int pushParams(lua_State*l, int count)
{
if (!mysql)return 0;
int ret = 0;
MYSQL_ROW row;
while (row = mysql_fetch_row(res))//获取具体的数据
{
int i = count;
while (i)
{
char *str = row[--i];
lua_pushstring(l, str);
++ret;
cout << str << " ";
}
cout << endl; // << " " << sql_row[2] << endl;
}
cout << endl; cout << endl; cout << endl;
return ret;
}
void release()
{
if (res)mysql_free_result(res);
if (mysql)mysql_close(mysql);
}
private:
MYSQL *mysql ;
MYSQL_RES *res ;
};
int SQL_Script_Bridge(lua_State *l)
{
int top = lua_gettop(l);
const char * host = lua_tostring(l, top - 6);
int port = lua_tonumber(l, top - 5);
const char * user = lua_tostring(l, top - 4);
const char * pswd = lua_tostring(l, top - 3);
const char * table = lua_tostring(l, top - 2);
const char * sql = lua_tostring(l, top - 1);
int count = lua_tonumber(l, top);
cout << sql << count << endl;
SQLInterface s;
s.connect(user, pswd, host, table, port);
s.exec(sql);
int n = s.pushParams(l, count);
return n;
}
int SQL_Script_create(lua_State*l)
{
void * user = lua_newuserdata(l, sizeof SQLInterface);
SQLInterface* ins = (SQLInterface*)user;
ins->SQLInterface::SQLInterface();
return 1;
}
int SQL_Script_connect(lua_State*l)
{
int top = lua_gettop(l);
void * instance = lua_touserdata(l, top - 5);
const char * host = lua_tostring(l, top - 4);
int port = lua_tonumber(l, top - 3);
const char * user = lua_tostring(l, top - 2);
const char * pswd = lua_tostring(l, top - 1);
const char * table = lua_tostring(l, top);
SQLInterface* ins = (SQLInterface*)instance;
bool ret = ins->connect(user, pswd, host, table, port);
lua_pushboolean(l,ret);
return 1;
}
int SQL_Script_execute(lua_State*l)
{
int top = lua_gettop(l);
void * instance = lua_touserdata(l, top - 2);
const char * sql = lua_tostring(l, top - 1);
int row_count = lua_tonumber(l, top);
SQLInterface* ins = (SQLInterface*)instance;
ins->exec(sql);
int n = ins->pushParams(l, row_count);
return n;
}
int SQL_Script_release(lua_State*l)
{
int top = lua_gettop(l);
void * instance = lua_touserdata(l, top);
SQLInterface* ins = (SQLInterface*)instance;
return 0;
}
sql.lua
Lua 脚本侧的封装模块。后续可以在此基础上补充参数校验和错误处理，以提升健壮性。
local t={};
t.config=require("sql_config");
--exec the sql
--return the res table which is one by one
function t:exec(sql,row_count)
local c=t.config;
local t={ SQL_Script_Bridge(c.host , c.port , c.user , c.pwd , c.db , sql,row_count)};
return t;
end
function t:create()
return SQL_Script_create();
end
function t:connect(ins)
local c=t.config;
local bool = SQL_Script_connect(ins,c.host , c.port , c.user , c.pwd , c.db);
end
function t:release(ins)
SQL_Script_release(ins);
end
function t:execute(ins,sql,col_count)
local t={ SQL_Script_execute(ins, sql,col_count)};
return t;
end
return t;