From 7598ed496d61d843706fea44dcf64dae64992280 Mon Sep 17 00:00:00 2001
From: kiritow <1362050620@qq.com>
Date: Mon, 7 Aug 2017 10:55:28 +0800
Subject: [PATCH] Update MySQLConn

---
 MySQLWrapper.cpp | 32 ++++++++++++++++++++++++++++++--
 MySQLWrapper.h   |  6 ++++--
 2 files changed, 34 insertions(+), 4 deletions(-)

diff --git a/MySQLWrapper.cpp b/MySQLWrapper.cpp
index c2ae5ee..9b90daa 100644
--- a/MySQLWrapper.cpp
+++ b/MySQLWrapper.cpp
@@ -1,5 +1,11 @@
 #include "MySQLWrapper.h"
 #include "MySQLInclude.h"
+#include <string>
+using namespace std;
+
+/**********************
+MySQL Result Class.
+**********************/
 
 struct MySQLResult::impl
 {
@@ -48,9 +54,15 @@ void MySQLResult::stepRow(const std::function<void(char** RowPtr, unsigned long*
     }
 }
 
+
+/**********************
+MySQL Connection Class.
+**********************/
+
 struct MySQLConn::impl
 {
     MYSQL m;
+    string lasterr;
 };
 
 MySQLConn::MySQLConn() : pimpl(new impl)
@@ -65,7 +77,15 @@ MySQLConn::~MySQLConn()
 
 int MySQLConn::connect(const char* host, const char* user, const char* passwd, const char* db, unsigned int port)
 {
-    return (mysql_real_connect(&(pimpl->m),host,user,passwd,db,port,NULL,0)==NULL)?0:-1;
+    if(mysql_real_connect(&(pimpl->m),host,user,passwd,db,port,NULL,0)==NULL)
+    {
+        pimpl->lasterr=mysql_error(&(pimpl->m));
+        return -1;
+    }
+    else
+    {
+        return 0;
+    }
 }
 
 int MySQLConn::exec(const std::string& SQLCommand, const std::function<void(MySQLResult&)>& func)
@@ -73,8 +93,10 @@ int MySQLConn::exec(const std::string& SQLCommand, const std::function<void(MySQ
     if(mysql_real_query(&(pimpl->m),SQLCommand.c_str(),SQLCommand.size())!=0)
     {
         /// Failed to Query
+        pimpl->lasterr=mysql_error(&(pimpl->m));
         return -1;
     }
+
     MYSQL_RES* pres=mysql_store_result(&(pimpl->m));
     if(pres==nullptr)
     {
@@ -87,6 +109,7 @@ int MySQLConn::exec(const std::string& SQLCommand, const std::function<void(MySQ
         else
         {
             /// Failed to store result.
+            pimpl->lasterr=mysql_error(&(pimpl->m));
             return -2;
         }
     }
@@ -94,7 +117,7 @@ int MySQLConn::exec(const std::string& SQLCommand, const std::function<void(MySQ
     MySQLResult res;
     res.pimpl->res=pres;
 
-    func(res);
+    if(func) func(res);
 
     /// MySQL_RES will be released normally by MySQLResult::~MySQLResult()
     return 0;
@@ -109,3 +132,8 @@ uint64_t MySQLConn::getAffectedRows()
 {
     return mysql_affected_rows(&(pimpl->m));
 }
+
+const std::string& MySQLConn::getError()
+{
+    return pimpl->lasterr;
+}
diff --git a/MySQLWrapper.h b/MySQLWrapper.h
index 67dabb0..c580474 100644
--- a/MySQLWrapper.h
+++ b/MySQLWrapper.h
@@ -32,13 +32,15 @@ public:
     ~MySQLConn();
 
     /// 数据库连接
+    /// 返回值: 0:连接正常, -1:连接错误
     int connect(const char* host,const char* user,const char* passwd,const char* db,unsigned int port);
 
     /// 执行SQL语句
-    int exec(const std::string& SQLCommand,const std::function<void(MySQLResult&)>& res);
+    /// 返回值: 1: 语句执行正常,无返回结果(func未执行) 0:语句执行正常,返回结果集交付func执行. -1:语句执行错误.(mysql_real_query失败) -2: 语句执行正确,获取结果出现错误
+    int exec(const std::string& SQLCommand,const std::function<void(MySQLResult&)>& func);
 
     /// 获取错误信息
-    const char* getError();
+    const std::string& getError();
 
     /// 当结果为空时用于判断数据库运行正常与否
     unsigned int getFieldCount();