目录
一、连接外网数据库遇到的问题
先抛出问题，就是连接内网数据库不会报错，连接外网时和查询时就报这个错：
The given key 'utf8mb4' was not present in the dictionary.
二、解决问题的方案
1、建立连接时报以上的错，在建立连接时添加这句 charset=utf8，即可解决。
public static void OpenSql()
{
try
{
string connectionString = string.Format("Server = {0};port={1};Database = {2}; User ID = {3}; Password = {4};charset=utf8", host, "3306", database, id, pwd);
dbConnection = new MySqlConnection(connectionString);
dbConnection.Open();
}
catch (Exception e)
{
Debug.LogError("服务器连接失败！ " + e.Message);
}
}2.在内网增删改查都不会有问题，但是连外网时，查询就又报上面的错，插入数据没问题！
换了个MySql.Data.dll动态链接库就解决了！
新的MySql.Data.dll依赖了几个别的库，BouncyCastle.Crypto.dll、Google.Protobuf.dll、Renci.SshNet.dll、SshNet.Security.Cryptography.dll
新的MySql.Data.dll从VS里即可找到，用VS连接过MySql数据库的就有，需要下载一个支持文件VS才能连接Mysql。
动态链接库下载地址：
https://download.csdn.net/download/hack_yin/85635678三、建表，增删改查
工具类SqlTools
/*----------------------------------------------------------------
Created by 王银
文件名: SqlTools.cs
创建时间： 2022/6/13
文件功能描述: SqlTools工具类
Copyright © 2022年 王银 All rights reserved.
----------------------------------------------------------------*/
using UnityEngine;
using System;
using System.Data;
using MySql.Data.MySqlClient;
public class SqlTools
{
public static MySqlConnection dbConnection;
static string host = "114.55.165.42";
static string id = "zhouyi";
static string pwd = "xZMGeGKwA8k43bNj";
static string database = "zhouyi";
public SqlTools()
{
OpenSql();
}
public static void OpenSql()
{
try
{
string connectionString = string.Format("Server = {0};port={1};Database = {2}; User ID = {3}; Password = {4};charset=utf8", host, "3306", database, id, pwd);
dbConnection = new MySqlConnection(connectionString);
dbConnection.Open();
}
catch (Exception e)
{
Debug.LogError("服务器连接失败！ " + e.Message);
}
}
public DataSet CreateTable(string name, string[] col, string[] colType)
{
if (col.Length != colType.Length)
{
Debug.LogError("columns.Length != colType.Length");
}
string query = "CREATE TABLE " + name + " (" + col[0] + " " + colType[0];
for (int i = 1; i < col.Length; ++i)
{
query += ", " + col[i] + " " + colType[i];
}
query += ")";
return ExecuteQuery(query);
}
/// <summary>
/// CREATE TABLE `NewTable` (`id` int NOT NULL AUTO_INCREMENT,`content` longtext NOT NULL ,PRIMARY KEY(`id`));
/// 建表时设置主键，让id自己增加
/// </summary>
/// <returns></returns>
public DataSet CreateTableAutoID(string name, string[] col, string[] colType)
{
if (col.Length != colType.Length)
{
Debug.LogError("columns.Length != colType.Length");
}
string query = "CREATE TABLE " + name + " (" + col[0] + " " + colType[0] + " NOT NULL AUTO_INCREMENT";
for (int i = 1; i < col.Length; ++i)
{
query += ", " + col[i] + " " + colType[i];
}
query += ", PRIMARY KEY (" + col[0] + ")" + ")";
return ExecuteQuery(query);
}
/// <summary>
/// INSERT INTO `testTable` VALUES (0, 'aa', 'ss', 'dd');
/// </summary>
/// <param name="tableName"></param>
/// <param name="values"></param>
/// <returns></returns>
//插入一条数据
public DataSet InsertInto(string tableName, string[] values)
{
string query = "INSERT INTO " + tableName + " VALUES (" + "'" + values[0] + "'";
for (int i = 1; i < values.Length; ++i)
{
query += ", " + "'" + values[i] + "'";
}
query += ")";
return ExecuteQuery(query);
}
//插入部分ID
/// <summary>
///数据库语法
/// 插入数据
/// INSERT INTO tableName(id, name) VALUES('s_1001', 'zhangSan');
/// INSERT INTO tableName VALUES('s_1002', 'liSi', 32, 'female');
/// <param name="tableName"></param>
/// <param name="col"></param>
/// <param name="values"></param>
/// <returns></returns>
public DataSet InsertDataIntoTable(string tableName, string[] col, string[] values)
{
if (col.Length != values.Length)
{
Debug.LogError("columns.Length != colType.Length");
}
string query = "INSERT INTO " + tableName + " (" + col[0];
for (int i = 1; i < col.Length; ++i)
{
query += ", " + col[i];
}
query += ") VALUES (" + "'" + values[0] + "'";
for (int i = 1; i < values.Length; ++i)
{
query += ", " + "'" + values[i] + "'";
}
query += ")";
return ExecuteQuery(query);
}
public DataSet SelectWhere(string tableName, string[] items, string[] col, string[] operation, string[] values)
{
if (col.Length != operation.Length || operation.Length != values.Length)
{
Debug.LogError("col.Length != operation.Length != values.Length");
}
string query = "select " + items[0];
for (int i = 1; i < items.Length; ++i)
{
query += ", " + items[i];
}
query += " from " + tableName + " where " + col[0] + operation[0] + "" + values[0] + "";
for (int i = 1; i < col.Length; ++i)
{
query += " AND " + col[i] + operation[i] + "" + values[0] + "";
}
return ExecuteQuery(query);
}
/// <summary>
/// 用id从表中查找
/// </summary>
/// <param name="id"></param>
/// <returns></returns>
public DataSet SelectWhereId(string tableName, int id)
{
string query = "select * from " + tableName + " where id=" + id;
return ExecuteQuery(query);
}
public DataSet SelectWhereId(int id)
{
string query = "select * from textbook where id=" + id;
return ExecuteQuery(query);
}
public DataSet SelectAllTable(string tableName)
{
string query = "select * from " + tableName;
return ExecuteQuery(query);
}
/// 修改数据
/// UPDATE tableName SET name =’liSi’, age=’20’ WHERE age>50 AND gender =’male’;
public DataSet UpdateInto(string tableName, string[] cols, string[] colsvalues, string selectkey, string selectvalue)
{
string query = "UPDATE " + tableName + " SET " + cols[0] + " = " + colsvalues[0];
for (int i = 1; i < colsvalues.Length; ++i)
{
query += ", " + cols[i] + " =" + colsvalues[i];
}
query += " WHERE " + selectkey + " = " + selectvalue + " ";
return ExecuteQuery(query);
}
/// 删除数据
/// DELETE FROM tableName WHERE name=’changHao’ OR age > 30;
/// DELETE FROM tableName;
/// truncate 是先DROP TABLE，再CREATE TABLE。而且TRUNCATE删除的记录是无法回滚的，但DELETE删除的记录是可以回滚的
/// TRUNCATE TABLE stu;
public DataSet Delete(string tableName, string[] cols, string[] colsvalues)
{
string query = "DELETE FROM " + tableName + " WHERE " + cols[0] + " = " + colsvalues[0];
for (int i = 1; i < colsvalues.Length; ++i)
{
query += " or " + cols[i] + " = " + colsvalues[i];
}
return ExecuteQuery(query);
}
public void Close()
{
if (dbConnection != null)
{
dbConnection.Close();
dbConnection.Dispose();
dbConnection = null;
}
}
public static DataSet ExecuteQuery(string sqlString)
{
if (dbConnection.State == ConnectionState.Open)
{
DataSet ds = new DataSet();
try
{
Debug.Log("<color=red>" + sqlString + "</color>");
MySqlCommand sqlCmd = new MySqlCommand(sqlString, dbConnection);
MySqlDataAdapter da = new MySqlDataAdapter(sqlCmd);
da.Fill(ds);
}
catch (Exception ee)
{
Debug.LogError(sqlString + "\r" + ee.Message);
}
return ds;
}
return null;
}
}
SqlScript.cs 数据库的建表、增删改查操作
/*----------------------------------------------------------------
Created by 王银
文件名: SqlScript.cs
创建时间： 2022/6/13
文件功能描述: Unity连接外网数据库，建表，增删改查等操作
Copyright © 2022年 王银 All rights reserved.
----------------------------------------------------------------*/
using UnityEngine;
using System;
using System.Data;
public class SqlScript : MonoBehaviour
{
void Start()
{
try
{
SqlTools sql = new SqlTools();
//创建数据表，各数据非空，主键id自增加
sql.CreateTableAutoID("newtextbook", new string[] { "id", "name", "content", "other" }, new string[] { "int", "text", "longtext", "text" });
//插入数据
sql.InsertDataIntoTable("newtextbook", new string[] { "name", "content", "other" }, new string[] { "test1", "This is test info 1.", "no.1" });
sql.InsertDataIntoTable("newtextbook", new string[] { "name", "content", "other" }, new string[] { "test2", "This is test info 2.", "no.2" });
sql.InsertDataIntoTable("newtextbook", new string[] { "name", "content", "other" }, new string[] { "test3", "This is test info 3.", "no.3" });
//查询数据
DataSet ds = sql.SelectWhere("newtextbook", new string[] { "name", "content" }, new string[] { "id" }, new string[] { "=" }, new string[] { "1" });
if (ds != null)
{
DataTable table = ds.Tables[0];
Debug.Log("Select1-> name: " + table.Rows[0][0] + "content: " + table.Rows[0][1]);
}
//查询整表
ds = sql.SelectAllTable("newtextbook");
if (ds != null)
{
DataTable table = ds.Tables[0];
//foreach (DataRow row in table.Rows)
//{
// foreach (DataColumn column in table.Columns)
// {
// Debug.Log("SelectAllTable : "+row[column]);
// }
//}
int count = table.Rows.Count;
for (int i = 0; i < count; i++)
{
Debug.Log("SelectAllTable id: " + table.Rows[i][0] + ", name: " + table.Rows[i][1] + ", content: " + table.Rows[i][2]);
}
}
//修改数据
sql.UpdateInto("newtextbook", new string[] { "name", "content" }, new string[] { "'testupdate'", "'uptate info'" }, "id", "2");
//新建查询
ds = sql.SelectWhere("newtextbook", new string[] { "name", "content" }, new string[] { "id" }, new string[] { "=" }, new string[] { "2" });
if (ds != null)
{
DataTable table = ds.Tables[0];
Debug.Log("name: "+table.Rows[0][0] + " content: " + table.Rows[0][1]);
}
//删除数据
sql.Delete("newtextbook", new string[] { "id" }, new string[] { "3"});
//查询整表
ds = sql.SelectAllTable("newtextbook");
if (ds != null)
{
DataTable table = ds.Tables[0];
int count = table.Rows.Count;
for (int i = 0; i < count; i++)
{
Debug.Log("SelectAllTable id: " + table.Rows[i][0] + ", name: " + table.Rows[i][1] + ", content: " + table.Rows[i][2]);
}
}
//关闭数据连接
sql.Close();
}
catch (Exception e)
{
Debug.LogError(e.Message);
}
}
}
效果图
输出的红色部分为数据库语句，普通的为正常 Debug.Log
