SQL CONVERT 从 varbinary 到 varchar

另一件事要注意:您的存储过程:ALTER PROCEDURE insertPlayerImage@playerID varchar(9),@profileImage varchar(max),@pending 字符(1)作为转换(varbinary(max)，@profileImage)插入播放器图像( playerID , profileImage , 待定)价值观( @playerID , @profileImage , @pending )走 不是合法的 SQL.Convert() 是一个函数，而不是 SQL 语句.它甚至不编译.如果您尝试将 varchar 参数 @profileImage 转换为 varbinary，您将不得不按照> 声明@image varbinary(max)set @image = convert(varbinary(max),@profileImage)如果你的存储过程有签名创建程序dbo.insertPlayerImage@playerId varchar(9) ,@profileImage varbinary(max) ,@pending 字符(1)作为...那么这段代码就可以了:public int insertProfileImage( string playerId , byte[] profileImage , bool pending ){if ( string.IsNullOrWhiteSpace(playerId) ) throw new ArgumentException("playerId") ;if ( profileImage == null || profileImage.Length 但是，如果您为图像数据传递 null，则需要更改参数值的设置方式.类似的东西:command.Parameters.AddWithValue( "@profileImage" , profileImage != null ? (object)profileImage : (object)DBNull.Value ) ;或SqlParameter p = new SqlParameter( "@profileImage" , SqlDbType.VarBinary ) ;p.Value = DBNull.Value ;if ( profileImage != null ){p.Value = profileImage ;}命令.Parameters.Add(p);I'm using a C# application and it looks like its ready to insert the image to my database, but my stored procedure spits out an implicit conversion error. I read the image into a byte array and pass the byte array to my stored procedure. It expects a varbinary parameter, hence the error. So I alter my stored procedure to be:ALTER PROCEDURE insertPlayerImage @playerID varchar(9), @profileImage varchar(max), @pending char(1)AS CONVERT(varbinary(max), @profileImage)INSERT INTO PlayerImage(playerID, profileImage, pending)VALUES(@playerID, @profileImage, @pending)GOwhich tells me it expects a varchar (my byte array) and convert the array to a varbinary file. Well my stored procedure doesn't like the the convert line i have. but if I simply do SELECT CONVERT(varchar, GETDATE());it works. All google searches point back to converting the date, almost as if its the only thing you can use a convert on. 解决方案 Are you using SQL Server? If so, see this page for the SQL data type to CLR data type mappings: http://msdn.microsoft.com/en-us/library/cc716729.aspxSQL Server char, varchar, nchar and nvarchar all map to/from a C# string (though a char[] will work as well).SQL Server binary andvarbinarymap to/from a C#byte[]`.What's the actual problem you're having?Further, if you're passing binary data as a varchar to SQL Server, I would expect it to get munged in the tranformation between UTF-16 (CLR internal string encoding) to whatever code page SQL Server is using.Another thing to note: your stored procedure:ALTER PROCEDURE insertPlayerImage @playerID varchar(9), @profileImage varchar(max), @pending char(1)AS CONVERT(varbinary(max), @profileImage) INSERT INTO PlayerImage ( playerID , profileImage , pending ) VALUES ( @playerID , @profileImage , @pending )GOisn't legal SQL. Convert() is a function, not a SQL statement. It doesn't even compile. If you are trying to convert your varchar parameter @profileImage to varbinary, you're going to have to do something along the lines of declare @image varbinary(max) set @image = convert(varbinary(max),@profileImage)If you're stored procedure has the signaturecreate procedure dbo.insertPlayerImage @playerId varchar(9) , @profileImage varbinary(max) , @pending char(1)as...Then this code will do you:public int insertProfileImage( string playerId , byte[] profileImage , bool pending ){ if ( string.IsNullOrWhiteSpace(playerId) ) throw new ArgumentException("playerId" ) ; if ( profileImage == null || profileImage.Length < 1 ) throw new ArgumentException("profileImage") ; int rowCount ; string connectString = GetConnectString() ; using ( SqlConnection connection = new SqlConnection(connectString) ) using ( SqlCommand command = connection.CreateCommand() ) { command.CommandType = CommandType.StoredProcedure ; command.CommandText = "dbo.insertPlayerImage" ; command.Parameters.AddWithValue( "@playerId" , playerId ) ; command.Parameters.AddWithValue( "@profileImage" , profileImage ) ; command.Parameters.AddWithValue( "@pending" , pending ? "Y" : "N" ) ; rowCount = command.ExecuteNonQuery() ; } return rowCount ;}If however, you're passing a null for image data, you'll need to change how the value of the parameter gets set. Something along the lines of:command.Parameters.AddWithValue( "@profileImage" , profileImage != null ? (object)profileImage : (object)DBNull.Value ) ;OrSqlParameter p = new SqlParameter( "@profileImage" , SqlDbType.VarBinary ) ;p.Value = DBNull.Value ;if ( profileImage != null ){ p.Value = profileImage ;}command.Parameters.Add( p ) ; 这篇关于SQL CONVERT 从 varbinary 到 varchar的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 上岸，阿里云！