As the MySql code does not use the SqlDbType, neither shall I. This appears to be a too small subset of values for MySql.
If I then use this, the MySqlParameter is always going to work?
--------------
Correct DataType Conversion for use of MySql, from MySqlHelper.
(Systerm.Data.DbType equal or larger than MySql Types)
MySqlEnumFieldTypes System.Data.DbType
FIELD_TYPE_DECIMAL Decimal
FIELD_TYPE_TINY Int16
FIELD_TYPE_SHORT Int16
FIELD_TYPE_SHORT U UInt16
FIELD_TYPE_LONG Int64
FIELD_TYPE_LONG U UInt64
FIELD_TYPE_FLOAT Single
FIELD_TYPE_DOUBLE Double
FIELD_TYPE_NULL String
FIELD_TYPE_TIMESTAMP String
FIELD_TYPE_LONGLONG Int64
FIELD_TYPE_LONGLONG U UInt64
FIELD_TYPE_INT24 Int64
FIELD_TYPE_INT24 U UInt64
FIELD_TYPE_DATE Date
FIELD_TYPE_TIME Time
FIELD_TYPE_DATETIME DateTime
FIELD_TYPE_YEAR Int16
FIELD_TYPE_NEWDATE Date
FIELD_TYPE_ENUM Int32
FIELD_TYPE_SET String
FIELD_TYPE_TINY_BLOB Binary
FIELD_TYPE_MEDIUM_BLOB Binary
FIELD_TYPE_LONG_BLOB Binary
FIELD_TYPE_BLOB Binary
FIELD_TYPE_VAR_STRING String
FIELD_TYPE_STRING String
[EMAIL PROTECTED] wrote:
Ben,
Understand below that I only refer to SQL Server. I don't know the
MySQL Mono.Data provider.
>Tim,
>
>I am running into a problem with the Data Types.
>
>The MySqlParameterCollection used the data types 'DbType'.
>In MySqlTypes there are the types MySqlEnumFieldTypes.
>There is also the SqlDbType in System.Data, as included in your email
>yesterday.
Ah, yes. There are several different type enumerations. If you
read the .NET Framework documentation closely, you may get an
understanding as to the difference between SqlDbType and DbType
in System.Data.
SqlDbType is a set of data types used by SQL Server. In fact,
most of these types are supported by SQL Server 7, with the exception
of SqlDbType.BigInt and SqlDbType.Variant, which are SQL Server 2000
types.
But, then, what is DbType? The way I see it, DbType is a more general
set of data types. Most of these types will work with SQL Server,
but then, some of them won't. For instance, DbType.UInt32 will not
work. Go ahead and try to create a SqlParameter with this DbType.
You'll get an ArgumentException when you do.
So, DbType is more abstract, and SqlDbType is specific to SQL Server.
Magically, with a SqlParameter, if you set the SqlDbType, it will
also set the corresponding DbType in the parameter and vice versa
(and, if you provide neither, both will be inferred from the type
of its value...I'm working on this at the moment).
The parameter object doesn't really use the DbType value, but it
is useful if you are writing more general-purpose code that you want
to switch to a different provider, etc.
>Unfortunatelly, none of these types hold the same list of data types.
>For example, the 'blob' types, which may I think be used with
>DbType.Binary. But I can't find any reasonable type for the 'TimeStamp'.
>
>This is with respect to your Parameter. However, since they are all
>being written as a String into the final SQL, should I just use String
>for any which don't match up?
No. You should not use string. In the SqlParameter example, assume
that you have a statement like
insert into my_table (int_value) values (@p1)
and you create a parameter @p1 with a string type (i.e. varchar)
with value 42. When you execute the statement, it will send to
SQL Server:
sp_executesql N'insert my_table (int_value) values (@p1)', N'@p1 varchar', '42'
which will give you a SqlException, because you're trying to insert
a varchar value into an int column.
If you want to look at the SqlClient code, you'll see that it isn't
*exactly* converting the value to a string. If it's a string type,
it actually converts the value to a string contained in apostrophes (').
Again, this may be completely different in MySQL.
>In short, does is actually matter what data type I use as long as MySQL
>understands it with respect to the colunm definition?
>
>Hope this is an easy question to answer,
Perhaps someone else will be able to talk about MySQL.
Cheers,
_______________________________________________ Mono-list maillist - [EMAIL PROTECTED] http://lists.ximian.com/mailman/listinfo/mono-list
