what error is this?

[FlyingBear]

I'm using .net with mysql. Sometimes, it reports below error. I'm inserting a string into table, the string value is 'http://www.mysite.com/?aid=1001'. It is just a string, I do not understand why it thinks ?aid is a parameter? how to fix this? The weird thing is sometimes the error shows up, sometimes, not.

thanks

bear
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A first chance exception of type 'MySql.Data.MySqlClient.MySqlException' occurred in MySql.Data.dll
MySql.Data.MySqlClient.MySqlException: Parameter '?aid' must be defined
at MySql.Data.MySqlClient.MySqlCommand.SerializeParameter(PacketWriter writer, String parmName)
at MySql.Data.MySqlClient.MySqlCommand.PrepareSqlBuffers(String sql)
at MySql.Data.MySqlClient.MySqlCommand.ExecuteNonQuery()