Hi i am using SQL Server 2012. i would like to view the system objects code/definition. can we view the system objects definition/code in SQL Server any version ?
wanted to know when i execute this query SELECT MONTH(18/200), MONTH(200/18) i am getting output 1 for both just want to know internal code what is going on and how it is giving output 1 for MONTH(200/18) ? to understand this looking for MONTH() function code.
Use INFORMATION_SCHEMA
An information schema view is one of several methods SQL Server
provides for obtaining metadata.
Information schema views provide an
internal, system table-independent view of the SQL Server metadata.
Information schema views enable applications to work correctly
although significant changes have been made to the underlying system
tables.
The information schema views included in SQL Server comply
with the ISO standard definition for the INFORMATION_SCHEMA.
answer to SELECT MONTH(18/200), MONTH(200/18) is any integer to the MONTH() interprets 0 as January 1, 1900. that's whey it is returning 1 1 as output.
Related
I have a stored procedure function as well as table in the SQL Server enterprise 2014. I also have data in the table. Now I need same table and data in PostgreSql(pgAdmin4).
Can anyone suggest to me the idea to migrate data to POSTGRESQL or any idea on creating the SQL script so that I can use psql to run the script?
Depending on how much data you have, you could script out the table and data. Then you could tweak the script as needed for PostgreSQL:
Right click on the SQL database > Tasks > Generate Scripts
On the "Choose Objects" screen, select your specific table then select "Next>"
On the "Set Scripting Options" screen, select "Advanced"
Find the option called "Types of data to script", then select "Schema and data" and select "OK"
Set the filename and continue through the dialog until the file is generated
Tweak the sql script for any specific PostgreSQL syntax
If there is a larger amount of data, you might look into some type of data transfer tool like SSIS.
Exporting the table structure and data as Josh Jay describes will likely require some fixes where the syntax doesn't match, but it should be doable if not tedious. Luckily there are existing conversion tools available to help.
You could also try using a foreign data wrapper to map the tables in SQL Server to a running instance of PostgreSQL. Then it's just a matter of copying tables. Depends on your needs and where each database server is located relative to one another.
The stored procedures will be far more difficult to handle unfortunately. While Oracle's pl/sql language is substantially similar to PostgreSQL's pl/pgsql, MS SQL Server/Sybase's TransactSQL dialect on the other hand is different enough to require rewrites. If the TransactSQL functions also access .Net objects, the migration task may end up far more difficult as you reimplement dependencies or find logical equivalents.
using SQL server 2014 I am able to select without specifying the schema name when it is NOT DBO.
We are now switching over to SQL 2016 and I am no longer able to select without adding the schema name?
Problem: Going back into each stored proc to add the schema name in would take a lot of time so I was wondering if it is possible to ignore the schema name somehow? I have been searching google but haven't found anything..
The procs are used in our SSRS reports, which there are over 100 and some are embedded into the reports so if there is a way to avoid having to change each one that would be great!
It seems the default schema is a property of the connecting user. Maybe you should check how the new "migrated" user has been defined.
I have a MS Access query that is based on a linked ODBC table (Oracle).
I'm troubleshooting the poor performance of the query here: Access not properly translating TOP predicate to ODBC/Oracle SQL.
SELECT ri.*
FROM user1_road_insp AS ri
WHERE ri.insp_id = (
select
top 1 ri2.insp_id
from
user1_road_insp ri2
where
ri2.road_id = ri.road_id
and year(insp_date) between [Enter a START year:] and [Enter a END year:]
order by
ri2.insp_date desc,
ri2.length desc,
ri2.insp_id
);
The documentation says:
When you spot a problem, you can try to resolve it by changing the local query. This is often difficult to do successfully, but you may
be able to add criteria that are sent to the server, reducing the
number of rows retrieved for local processing.
In many cases you will find that, despite your best efforts, Office Access still retrieves some entire tables unnecessarily and
performs final query processing locally.
However, it's occurred to me that I don't really understand what sort of SQL I should be writing to make both Access and ODBC/Oracle happy.
Should I be writing some sort of generic SQL that Access can understand in a local query AND that can be easily translated to ODBC/Oracle SQL? Is generic SQL a real thing?
What kind of SQL does the ODBC driver use? It depends as typically MS Access has three types of external data connections that interfaces with different SQL dialects each with the ODBC API.
Linked tables that acts like local tables but are ODBC connected data sources and not stored locally. Once they are incorporated in an Access app, these tables can only use MS Access' SQL dialect. They can be joined with local or even other backend tables from other sources.
Hence, why TOP is available in MS Access and not Oracle. You are essentially using Access SQL to manipulate Oracle data. ODBC serves as the origin point of data while Access' Jet/ACE SQL engine does the processing and resultset viewing in cached memory.
Pass-through queries that do not see local tables or anything else in local app's environment. Such queries use the SQL dialect of the connected database here being Oracle.
Hence, why TOP is NOT available in Oracle and double quotes are allowed in column identifiers. Such quoting would fail in MS Access. Essentially, you are using Oracle SQL to manipulate Oracle data in an Access app. You can take the output of the sqlout.txt log and run it in a pass-through query ODBC-connected to your Oracle database.
ADO/DAO Recordsets that are run entirely via code such as VBA and are direct connections to data sources and uses the connecting database's dialect.
Here, you using Oracle SQL to manipulate Oracle data in an Access app via the ODBC API.
In each one of these types, you will have to connect to a backend ODBC data source. You do not even need to use the GUI but can use Access' object library to create linked tables (see DoCmd.TransferDatabase) and pass through querydefs (see QueryDef.Connect or .Execute).
I suspect the sqlout.txt log you see are translations of the ODBC calls to its native dialect.
To build on #Parfait's point #1:
From Microsoft Access Developer's Guide to SQL Server by Mary Chipman and Andy Baron:
Optimizing Access Queries:
There's a common misconception that the Jet engine always retrieves all the data in linked SQL Server tables and then processes the data locally. This is not usually true. Jet is perfectly capable of sending efficient queries to SQL Server over ODBC and retrieving only the rows required. However, in some cases, Jet will in fact be forced to fetch all the data in certain tables first and then process it. You should be aware of when you are forcing Jet to do this and be sure that it is justified. The following are some general guidelines to follow when creating your Access queries:
Using expressions that can't be evaluated by the server will cause Jet to retrieve all the data required to evaluate those expressions locally. The impact of using Access-specific expressions, such as domain aggregate functions, Access financial functions, or custom VBA functions will vary depending on where in your query the expressions are used. Using such an expression in the SELECT clause will usually not cause a problem because no extra data will be returned. However, if the expression is in the WHERE clause, that criterion cannot be applied on the server, and all the data evaluated by the expression will have to be returned.
With multiple criteria, as many as possible will be processed on the server. This means that even if you use criteria that you know include functions that will need to be processed by Jet, adding other criteria that can be handled by the server will reduce the number of records that Jet has to process. Adding criteria on indexed columns is especially helpful.
Query syntax that includes an Access-specific extension to SQL, not supported by the ODBC driver, may force processing to be done on the client by Access. For example, even though SELECT TOP 5 PERCENT is now supported by SQL Server, it is not supported by the ODBC driver. If you use that syntax in an Access query, Jet will need to retrieve all the records and calculate which ones are in the top 5 percent. On the other hand, even though crosstab queries are specific to Access, Jet will translate them into simple GROUP BY queries and fetch just the required data in one trip to the server unless problematic criteria is used.
Heterogeneous joins between local and remote tables or between remote tables that are in different data sources will, of course, have to be processed by Jet after the source data is retrieved. However, if the remote join field is indexed and the table is large, Jet will often use the index to retrieve only the required rows by making multiple calls to the remote table, one fore each row required.
Jet allows you to mix data types within [typo - fix later] of UNION queries and within expressions, but SQL server doesn't. Such mixing of data types will force processing to be done locally.
Multiple outer joins in one query will be processed locally.
The most important factor is reducing the total number of records being fetched. Jet will retrieve multiple batches of records in the background until the result set is complete, so even though you may seem to get results back immediately, a continuing load is being placed on the server for large result sets.
Note: this book is quite old (published in 2000) and is in reference to Jet Engine. I imagine things might be slightly different in newer versions of Access which use ACE, although I don't have a source to back this up.
I have 13 SQL databases some 2005 others 2008, on a VPN. I'd like to take all of the data from the "Employees" table on each database and make it a view at each location. I would then like to publish these views to 1 database on another server, all in one table marking where each came from within the origninal databases. For example the database where all the information goes to would look like this:
User Name Location
bik Bob K 1
JS John S 2
Etc.
Any help is appreciated.
I assume you want the data on the final server to be viewable, but not modifiable, and to reflect changes made to the source databases?
This would probably not perform all that well, but one do-it-yourself-way to do it would be the following (disclaimer: I haven't tried doing this myself):
Set up all the source servers as linked servers on the final server.
Create a view in this form:
SELECT *, 1 as Location
FROM [Linked Server 1].Database1.dbo.Table1
UNION ALL
SELECT *, 2 as Location
FROM [Linked Server 2].Database2.dbo.Table2
... etc ....
You might want to read this documentation on distributed queries, if you haven't already.
I believe it's also possible to use SSIS as the source of a distributed query, but a quick scan through the documentation didn't find anything about it. I mention that because SSIS would make pulling and transforming data from disaparate data sources very easy, and if you could use the final recordset as a data source, you could use an SSIS package as the backend to your view. However, again, performance would probably require considerable tuning.
If the queries don't have to be real time you could look into using SQL Server Integration Services (SSIS) to pull in the data to a local DB. you could schedule the job to run hourly/daily/weekly..
We're working on a product that may or may not have differing license schema for different databases. In particular, a lower-tier product would run on SQLExpress, but we don't want the end user to be able to use a "full-fat" SQL install - benefiting from the price cut. Clearly this must also be the case for other DBs, so Oracle may command a higher price than SQL, for instance (hypothetically).
We're using Entity Framework. Obviously this hides all the neatness of accessing the core schema and using sp_version or whatever it is. We'd rather not pre-load the condition by running a series of SQL commands (one for each platform) and see what comes back, as this would limit our DB options. But if necassary, we're prepared to do it.
So, is it possible to get this using EF itself? DBContext.COnnection.ServerVersion only returns something like "9.00.1234" (for SQL Server 2005). I would assume (though haven't yet checked - need to install an instance) SQLExpress would return something similar - "pretending" it is full-fat. Obviously, we have no Oracle/MySQL/etc. instance so can't establish whether that returns text "Oracle" or whatever.
I can't comment on Entity Framework itself, but for MS SQL Server you can use the T-SQL function SERVERPROPERTY to detect extra information that relates to licence/cost
SELECT
SERVERPROPERTY('LicenseType'),
SERVERPROPERTY('NumLicenses'),
SERVERPROPERTY('EngineEdition'),
SERVERPROPERTY('Edition')
Otherwise, it's simply not exposed in the client code