We're migrating form SQL Server 2005 to 2014 for a pretty large environment. And we've noticed that OPENQUERY behaves differently when interacting with MySQL database when it comes to datetime. Previously, it would translate just fine to DATETIME column. With 2014 (I assume started in 2008 or so), it now converts to DATETIME2 (with maximum precision). This causes problems when comparing to or inserting into DATETIME columns.
Is there a way to specify on a server-level (or specify default) for which type those will translate to? Rewriting all of the queries will be quite an undertaking, and I'd like to avoid this now, if possible (rather rewrite as we edit or introduce new things).
Try to Use VARCHAR datatype while migration of date fields, and it is always easy to Convert/Cast in various types as per need.
I've developed my website using EF4 and SQL Server 2005, but when moving to the staging site it turns out that they use SQL Server 2000.
Now I'm getting this error, which I believe is related to SQL Server 2000:
Incorrect syntax near '('. 'row_number' is not a recognized function name.
Is there a way of fixing this?
Thanks
EF v4 does not support SQL Server 2000. More details here:
https://connect.microsoft.com/VisualStudio/feedback/details/499186/entity-framework-v2-doesn-t-support-sql-2000
I came across the exact same problem and as per the comments/responses on StackOverflow I had almost given up and flicked it to client to upgrade their database to > 2000 version. Unfortunately that wasn't possible for them due to many other issues. I had to go around googling for a solution and from somewhere I found a work-around.
This is what I did.
Right clicked the ModelName.EDMX file -> Open With
Selected XML (Text) Editor
Found ProviderManifestToken="2005" and replaced it with
ProviderManifestToken="2000"
Published the changes and voila!
Now the reason I'm saying it's a work-around (not a solution) is because
If you update your model from database again and your development
machine database is >= 2000 (which is likely to be a case as SQL
2000 connection is not supported at all by MS according to this
article) this value in the XML will change automatically
Also, the queries generated by EF after this change have worked in
my situation but I cannot guarantee that all the queries ever
generated by your application would work without any problems
Row_Number() returns the sequential number for a each row returned. Are you calling Row_number(), or is the entity framework?
Either way, you may be able to write a user-defined function that re-implements ROW_NUMBER. Stackoverflow post on this here:
ROW_NUMBER Alternative for SQL Server 2000
Not sure this is going to do any good in the long run; you're likely to find that you get around this problem only to encounter the next reason that EF doesn't work on SQL 2000. But, it might be worth the few minutes to try.
I have a few SQL Server tables with a datetime field that really only has to contain dates... and the fact that it's a datetime object violates data integrity, because it's possible for data to be inserted with a time - which isn't really valid for this field. The result is that we have to convert it and strip off the time every single time we use it. We've considered adding triggers to make sure that no data can even get in with a time attached... but it seems to me that this should really be part of the database software, and shouldn't need to be specifically programmed each time.
Why doesn't SQL Server have separate date and time data types? Is this going to change in the near future? Do other database platforms have this functionality?
SQL Server 2008 has DATE and TIME data types.
What version are you using?
SQL Server has a pure date and time data type since version 2008, they also added a bunch of new datetime types, now it also goes all the way back to year 1 instead of 1753
This is the second time it happens to me and before modifying a 3rd party Database structure I wanted to know if anyone knew a better solution:
I'm accessing a MS SQL Server 2008 from a Lotus Notes Agent (Notes 7) to retrieve some data. I use LSXODBC and my "Select" statement works perfect... Except that my agent cannot "understand" Nvarchar SQL Field types. Any other data types work ok (can get the values from number and dates fields without a problem).
It took me a while to figure it out, and I couldn't find a solution (other than modifying the field types on the SQL table to Varchar instead of nVarchar)
I could replicate this both in MS SQL 2005 and 2008.
Last "elegant" solution was to create an SQL view -instead of modifying table structure- with the varchar types instead of nvarchar. Works ok but I have to create a view for each table I'm retrieving data from.
I tried to set the Field type using FieldExpectedDataType Method but didn't work. Still got a DB_TYPE_UNDEFINED.
I thought there might be some configuration issues? or maybe I'm using an old LN Version / ODBC Driver version?
Any hint would be greatly appreciated.
Thank you in advance.
Diego
An old ODBC driver may not support unicode. It was not added until SQL Server 2000 (I'm fairly sure)
I've worked with T-SQL for years but I've just moved to an organisation that is going to require writing some Oracle stuff, probably just simple CRUD operations at least until I find my feet. I'm not going to be migrating databases from one to the other simply interacting with existing Oracle databases from an Application Development perspective. Is there are tool or utility available to easily translate T-SQL into Oracle SQL, a keyword mapper is the sort of thing I'm looking for.
P.S. I'm too lazy to RTFM, besides it's not going to be a big part of my role so I just want something to get me up to speed a little faster.
The language difference listed so far are trivial compared to the logical differences. Anyone can lookup NVL. What's hard to lookup is
DDL
In SQL server you manipulate your schema, anywhere, anytime, with little or no fuss.
In Oracle, we don't like DDL in stored procedures so you have jump through hoops. You need to use EXECUTE IMMEDIATE to perform a DDL function.
Temp Tables
IN SQL Server when the logic becomes a bit tough, the common thing is to shortcut the sql and have it resolved to a temp table and then the next step is done using that temp table.
MSSS makes it very easy to do this.
In Oracle we don't like that. By forcing an intermediate result you completely prevent the Optimizer from finding a shortcut for you. BUT If you must stop halfway and persist the intermediate results Oracle wants you to make the temp table in advance, not on the fly.
Locks
In MSSS you worry about locking, you have nolock hints to apply to DML, you have lock escalation to reduce the count of locks.
In Oracle we don't worry about these in that way.
Read Commited
Until recently MSSS didn't fully handle Read Committed isolation so you worried about dirty reads.
Oracle has been that way for decades.
etc
MSSS has no concept of Bitmap indexes, IOT, Table Clusters, Single Table hash clusters, non unique indexes enforcing unique constraints....
I get the impression most answers focus on migrating an entire database or just point to some differences between T-SQL and PL/SQL. I recently had the same problem. The Oracle database exists, but I need to convert a whole load of T-SQL scripts to PL/SQL.
I installed Oracle SQL Developer and ran the Translation Scratch Editor (Tools > Migration > Scratch Editor).
Then, just enter your T-SQL, choose the correct translation in the dropdown-list (it should default to 'T-SQL to PL/SQL'), and convert it.
I have to things to mention.
1) When I worked on Oracle 8, you could not do "Select #Result", you had to instead use the dummy table as follows "Select #Result from dual". Not sure if that ridiculousness still exists.
2) In the Oracle world they seem to love cursors and you better read up on them, they use them all the time AFAICS.
Good luck and enjoy,
it is not that different to MS SQL. Thankfully, I do not have to work with it anymore and I am back in the warm comfort of MS tools.
If you replace your ISNULL and NVL nonsense with COALESCE, it'll work in T-SQL and PL/SQL!
It's not trivial to map them back and forth, so I doubt there's a tool that does it automatically. But this link might help you out: http://vyaskn.tripod.com/oracle_sql_server_differences_equivalents.htm
The most important differences for plain T-SQL are:
NVL replaces ISNULL
SYSDATE replaces GETDATE()
CONVERT is not supported
Identity columns must be replaced with sequences <-- not technically T- or PL/ but just SQL
Note. I assume you do not use the deprecated SQL Server *= syntax for joins
#jodonell: The table you link to is a bit outdated, oracle has become somewhat more standards compliant after 9i supporting things like CASE and ANSI outer joins
I have done a few SQL server to oracle migrations. There is no way to migrate without rewriting the backend code. Too many differences between the 2 databases and more importantly differences between the 2 mind sets of the programmers. Many managers think that the 2 are interchangeable, I have had managers ask me to copy the stored procedures from SQL server and compile them in oracle, not a clue! Toad is by far the best tool on the market for supporting an oracle application. SQL developer is ok but was disappointing compared to toad. I hope that oracle will catch their product up to toad one day but it is not there yet. Have a good day :) chances are if you are migrating to oracle it is for a reason and in order to meet that requirement you will need to rewrite the back end code or you will have many issues.
In Oracle SQL Developer, there is a tool called Translation Scratch Editor. You can find it from Tools > Migration.
The Oracle SQL Developer is a free download from Oracle and it is an easy install.
If you're doing a one-off conversion, rather than trying to support two versions, you must look at Oracle Migration Workbench. This tool works with Oracle's SQLDeveloper (which you really should have if you are working with Oracle). This does a conversion of the schema, data, and some of the T-SQL to PL/SQL. Knowing both well, I found it did about an 80% job. Good enough to make it worth while to convert the bulk of procedures, and hand convert the remainder "tougher" unknown parts.
Not cheap ($995) but this tool works great: http://www.swissql.com/products/sql-translator/sql-converter.html
A few people have mentioned here converting back and forward. I do not know of a tool to convert from MSSQL to Oracle, but I used the free MS tool to convert a Oracle db to MSSQL and it worked for me and converted a large db with no problems I can call. It is similar to the Access to MSSQL tool that MS also provide for free. Enjoy
jOOQ has a publicly available, free translator, which can be accessed from the website here: https://www.jooq.org/translate
It supports DML, DDL, and a few procedural syntax elements. If you want to run the translation locally via command line, a license can be purchased and the command line works as follows:
$ java -cp jooq-3.11.9.jar org.jooq.ParserCLI -t ORACLE -s "SELECT substring('abcde', 2, 3)"
select substr('abcde', 2, 3) from dual;
See: https://www.jooq.org/doc/latest/manual/sql-building/sql-parser/sql-parser-cli
(Disclaimer, I work for the vendor)