I was trying to use Subsonic to generate my DAL, but I noticed a bug while generating Classes using LinqToEntities T4 templates.
I noticed that one of the columns in a table was having the type tinyint, while generating a Property for this column it created one which returns a byte[] instead of a byte.
Also another Table had a Column named ModifiedBy with the type set to smallint. Subsonic created the Property in the class correctly as short however in one of the PropertyChanged methods it was expecting a string for this field and was setting its value to Environment.UserName.
Has anyone faced this issue before?
TIA..
you may have solved this by now but..
Search in the file SQLServer.ttinclude for "tinyint"
You'll see a C# switch statement
Modify the one for tinyint to something more useful, such as Integer
Worked for me
Related
I'm storing a few fields and for the sake of simplicity lets call the field in question 'age'. Initially ES created the index for me and it ended up choosing the wrong field type for 'age'. It's a string type right now instead of a numeric type. I'm aware that, I should have defined the mappings myself to begin with and force the data values been sent to be consistently all strings or numeric values.
What I've right now is an index with a ton of data that uses a 'string' type for age with following values: 1, 10, 'na', etc..
Now my question is: if I were to change the mapping from string to integer, would indexing have any issues with the existing data values such as 'na' when being updated ??
I just wanted to ask first before I start creating a playground environment to test with a sample data set.
What you can update according to the doc:
new properties can be added to Object datatype fields.
new multi-fields can be added to existing fields.
doc_values can be disabled, but not enabled.
the ignore_above parameter can be updated.
Otherwise I am afraid you will have to create a new mapping and reindex your data, see this post for example
I am coding a cpp project with the database "postgreSQL".
I created a table in my database its type is character varying(40).
Now I need to SELECT these data FROM the table in my cpp project. I knew that I should use the library libpq, this is the interface of "postgreSQL" for c/cpp.
I have succeeded in selecting data from the table. Now I am considering if it's possible to get the data type of this table. For example, here I want to get character varying(40).
You need to use PQftype.
As described here: http://www.idiap.ch/~formaz/doc/postgreSQL/libpq-chapter17861.htm
And just take a look here about decoding return values: http://www.postgresql.org/message-id/da7021e0608040738l3b0880a1q5a76b838937f8c78#mail.gmail.com
You must also use PQfsize to get field size.
What built-in routine can I make use of to cast data of type LVARCHAR to data of type TEXT?
The larger context: I have a table with a column that has been defined as LVARCHAR(4096). Now a developer wishes to change the data type of this column to TEXT. Ideally this would be done with:
ALTER TABLE foo MODIFY bar TEXT;
...but in such a case the following error is puked to the screen:
ALTER TABLE can not modify column (bar) type. Need a cast from the current type to the new type.
I have read up on the CREATE CAST construction, but I cannot begin to think what on earth the proper conversion function would look like. Without a function, Informix will not allow the CREATE CAST to work. That is, if I do, simply:
CREATE CAST (LVARCHAR AS TEXT)
...Informix tells me that a cast function is required (which makes sense).
Beware, Informix developers: if you inadvertently run into a problem like this, there is no way to get out of it using SQL or DDL alone. Let me repeat that.
If you have a VARCHAR or an LVARCHAR column that you need to migrate to be a TEXT column, and if you cannot afford to lose data in that column, there is no way to do this in SQL or DDL.
Instead, you must write a program that does the conversion for you inside the database driver, in memory. In my case, I used JDBC mutable result sets and copied the column to a new column, letting the JDBC driver perform the conversion, then dropped the old column, and renamed the new column back to the old column. This general pattern is the only way to migrate existing character data into a TEXT column.
#Storm: Which version of IDS/ODBC are you using? AFAIK, IDS 9 or 10 can't do that without using specific embedded C in server (See boulder site), but in no way you can do that directly through SQL. Blob related functions or so.
Othe way is by using UNLOAD / LOAD.
In my scenario, we have lots of problems: no admin rights to enterprise server, as we are service providers, we only can use database, but cannot modify structure. We cannot modify TEXT fields only by launching queries.
I need to make a query like this:
SELECT PNPDeviceID FROM Win32_NetworkAdapter WHERE AdapterTypeId = 0
Trouble is, the AdapterTypeId column isn't always present. In this case, I just want everything, like so:
SELECT PNPDeviceID FROM Win32_NetworkAdapter
My WQL/SQL knowledge is extremely limited. Can anybody tell me how to do this in a single query?
EDIT:
A bit more background seems to be required: I am querying Windows for device information using WMI, which uses an SQL-like syntax. So, in my example, I am querying for network adapters that have an AdapterTypeId of 0.
That column is not always present however, meaning that if I enumerate through the returned values then "AdapterTypeId" is not listed.
EDIT 2:
Changed SQL to WQL; apparantly this is more correct.
I am assuming you mean the underlying schema is unreliable.
This is a highly unconventional situation. I suggest that you resolve the issue that is causing the column to not always be present, because to have the schema changing dynamically underneath your application is potentially (almost certainly) disastrous.
Update:
OK, so WQL lets you query objects with a SQL-like syntax but, unlike SQL, the schema can change underneath your feet. This is a classic example of a leaky abstraction, and I now hate WQL without ever having used it :).
Since the available properties are in flux, I am guessing that WQL provides a way to enumerate the properties for a given adapter. Do this, and choose which query to run depending upon the results.
After some Googling, there is an example here, which shows how to enumerate through the available properties. You can use this to determine if AdapterTypeId exists or not.
SELECT PNPDeviceID FROM Win32_NetworkAdapter WHERE AdapterTypeId = {yourDesire} OR AdapterTypeId IS NULL
I assume that you mean that this field is missing from the table.
Do you know before submitting the query if this field exists?
If yes then just create SQL dynamically, otherwise It think you will get syntax error in case of missing field
This is not an SQL question. SQL does not contemplate records with varying schemas in a single table source. Instead (as you mention) this is a different system using an "SQL-like" syntax. You'll have better luck if you recast the question using the actual product that you're trying to query, and information how that product deals with variable record structures is probably discussed in the documentation.
I'm trying to do a proof of concept using SubSonic 3 but Sstraight away i'm hitting numerous errors with the generation. I started making alterations to the generator settings but that seems a little odd when I'm just trying to do a simple one to one mapping of my DB.
Firstly I found an SP that had #delagate as an SP parameter name, this was easily fixed, but should probably be in the standard templates as a user shouldn't have to make template changes for this simple an issue.
Next I found that the system choked on two tables and tried to create signatures the same
the tables where
Field
Fields
now i know SubSonix 2 had a fixPluralClassName property but buggered if I can find one in the template for SubSonic 3
Any help on that one will get me started
Generally 'X' and 'Datum' type appendages/substitutions happen when you have used a 'reserved' word in a column or table name. In this case 'Reserved' being a word that Subsonic doesn't like to use for data objects.
A couple of rules I follow are;
Ensure both table names and column
names are not 'reserved' words (ie
'Data' or 'Int' or 'Table')
Ensure that each table has a primary key
Don't use date and time column types
as they are not supported yet
(DateTime is, just not Date and Time types)
Don't have a column with the same
name as the table
The Subsonic FAQ might be helpful.