C# MySqlException:Timeout expired-增加连接超时没有任何效果

我有一个查询，随着数据库大小的增加，执行该查询的时间会更长。查询是经过优化和必要的，但我的C控制台应用程序最近给了我以下错误：

Unhandled Exception: MySql.Data.MySqlClient.MySqlException: Timeout expired.

var command = new MySqlCommand(
    "SELECT * FROM tblPerson WHERE LastName = @Name AND Height > @Height AND BirthDate < @BirthDate", connection);

command.Parameters.AddWithValue("@Name", lastname);
command.Parameters.AddWithValue("@Height", height);
command.Parameters.AddWithValue("@Name", birthDate);

增加连接字符串中的连接超时没有帮助；我从

var command = new MySqlCommand(
    "SELECT * FROM tblPerson WHERE LastName = @Name AND Height > @Height AND BirthDate < @BirthDate", connection);

command.Parameters.AddWithValue("@Name", lastname);
command.Parameters.AddWithValue("@Height", height);
command.Parameters.AddWithValue("@Name", birthDate);

连接超时=28800

var command = new MySqlCommand(
    "SELECT * FROM tblPerson WHERE LastName = @Name AND Height > @Height AND BirthDate < @BirthDate", connection);

command.Parameters.AddWithValue("@Name", lastname);
command.Parameters.AddWithValue("@Height", height);
command.Parameters.AddWithValue("@Name", birthDate);

到

var command = new MySqlCommand(
    "SELECT * FROM tblPerson WHERE LastName = @Name AND Height > @Height AND BirthDate < @BirthDate", connection);

command.Parameters.AddWithValue("@Name", lastname);
command.Parameters.AddWithValue("@Height", height);
command.Parameters.AddWithValue("@Name", birthDate);

连接超时=128800

var command = new MySqlCommand(
    "SELECT * FROM tblPerson WHERE LastName = @Name AND Height > @Height AND BirthDate < @BirthDate", connection);

command.Parameters.AddWithValue("@Name", lastname);
command.Parameters.AddWithValue("@Height", height);
command.Parameters.AddWithValue("@Name", birthDate);

但是，尽管有了这个改变，我仍然会犯错误

var command = new MySqlCommand(
    "SELECT * FROM tblPerson WHERE LastName = @Name AND Height > @Height AND BirthDate < @BirthDate", connection);

command.Parameters.AddWithValue("@Name", lastname);
command.Parameters.AddWithValue("@Height", height);
command.Parameters.AddWithValue("@Name", birthDate);

如果从MySQL workbench运行查询，只需10秒左右，因此我不确定如何防止此未处理的异常

var command = new MySqlCommand(
    "SELECT * FROM tblPerson WHERE LastName = @Name AND Height > @Height AND BirthDate < @BirthDate", connection);

command.Parameters.AddWithValue("@Name", lastname);
command.Parameters.AddWithValue("@Height", height);
command.Parameters.AddWithValue("@Name", birthDate);

---

除了查询所需的时间之外，还有其他因素会导致此异常吗？

如果您能向我们展示您的方法，我们可以帮助您找到错误

var command = new MySqlCommand(
    "SELECT * FROM tblPerson WHERE LastName = @Name AND Height > @Height AND BirthDate < @BirthDate", connection);

command.Parameters.AddWithValue("@Name", lastname);
command.Parameters.AddWithValue("@Height", height);
command.Parameters.AddWithValue("@Name", birthDate);

如果说历史和其他东西教会了我什么，那就是

"You better be using Paramaterized SQL statements before posting any code" 

var command = new MySqlCommand(
    "SELECT * FROM tblPerson WHERE LastName = @Name AND Height > @Height AND BirthDate < @BirthDate", connection);

command.Parameters.AddWithValue("@Name", lastname);
command.Parameters.AddWithValue("@Height", height);
command.Parameters.AddWithValue("@Name", birthDate);

如果您不确定如何使用参数化命令，这里有一个示例，摘自我没有使用参数化SQL的答案之一

var command = new MySqlCommand(
    "SELECT * FROM tblPerson WHERE LastName = @Name AND Height > @Height AND BirthDate < @BirthDate", connection);

command.Parameters.AddWithValue("@Name", lastname);
command.Parameters.AddWithValue("@Height", height);
command.Parameters.AddWithValue("@Name", birthDate);

---

如果您还没有发布一些代码，请尝试这样做：

我以前遇到过这个问题。ConnectTimeout属性仅适用于连接到数据库时发生的超时，而不适用于查询

var command = new MySqlCommand(
    "SELECT * FROM tblPerson WHERE LastName = @Name AND Height > @Height AND BirthDate < @BirthDate", connection);

command.Parameters.AddWithValue("@Name", lastname);
command.Parameters.AddWithValue("@Height", height);
command.Parameters.AddWithValue("@Name", birthDate);

---

CommandTimeout指定查询返回的等待时间。我相信默认值是30秒。仔细检查MySql库的文档，但是对于SqlCommand，CommandTimeout的单位是秒而不是毫秒。

您也可以尝试在连接字符串中添加默认的CommandTimeout=360；乙二醇

var command = new MySqlCommand(
    "SELECT * FROM tblPerson WHERE LastName = @Name AND Height > @Height AND BirthDate < @BirthDate", connection);

command.Parameters.AddWithValue("@Name", lastname);
command.Parameters.AddWithValue("@Height", height);
command.Parameters.AddWithValue("@Name", birthDate);

Server=myServerAddress;Database=myDataBase;Uid=myUsername;Pwd=myPassword;default command timeout=20;

此选项可从Connector/NET 5.1.4版获得

var command = new MySqlCommand(
    "SELECT * FROM tblPerson WHERE LastName = @Name AND Height > @Height AND BirthDate < @BirthDate", connection);

command.Parameters.AddWithValue("@Name", lastname);
command.Parameters.AddWithValue("@Height", height);
command.Parameters.AddWithValue("@Name", birthDate);

---

[我从

中取消了此操作，更改了CommandTimeout而不是ConnectionTimeout。未处理的异常：System.ArgumentException:关键字不受支持。参数名称：Application.MainClass.MainString处的connecttimeout[]args噢，我需要更仔细地阅读您的命令超时。不是.public静态字符串ConnectionString=server=192.168.1.2；user=user1；database=database1；port=3306；password=testPW；Pooling=true；Connect Timeout=28800；Command Timeout=28800；我仍在测试中。谢谢Tim！自从我设置了命令超时之后，我还没有经历过超时，就像s一样hown在我上面的连接字符串中。在MySQL中也是秒。另外-0是无超时。

var command = new MySqlCommand(
    "SELECT * FROM tblPerson WHERE LastName = @Name AND Height > @Height AND BirthDate < @BirthDate", connection);

command.Parameters.AddWithValue("@Name", lastname);
command.Parameters.AddWithValue("@Height", height);
command.Parameters.AddWithValue("@Name", birthDate);