I am building a .NET disconnected client-server application that uses Entity Framework 5 (EF5) to generate a SQL Server CE 4.0 database from POCOs. The application allows the user to perform a bulk copy of data from the network SQL Server into the client's SQL Server CE database. This is very (VERY) slow, due to the constraints and indexes created by EF5. Temporarily dropping the constraints and indexes will reduce the 30-minute wait to 1 minute or less.
Before starting the bulk copy, the application executes queries to drop the constraints and indexes from the SQL Server CE tables. However, the commands fail, because EF5 created constraint names include the table schema name, dot, and table name. The dot in the constraint name is causing the drop command to fail, due to a parsing issue.
For example, POCO Customer creates table dbo.Customer with the primary key constraint PK_dbo.Customer_Id. The database performs as expected.
However, upon executing non-query:
ALTER TABLE Customer DROP CONSTRAINT PK_dbo.Customer;
SQL Server Compact ADO.NET Data Provider returns an error:
There was an error parsing the query.
[ Token line number = 1, Token line offset = 57, Token in error = . ]
Of course, using a secondary DataContext object that does not have foreign keys generate the database without the constraints, and then add them later works; but, that requires maintaining two DataContext objects and hopefully not forgetting to keep both updated. Therefore, I am looking for one of two solutions:
Compose the DROP statement in such a way that the . character is parsed
Prevent EF5 from using the . character in the constraint and index names
Thank you in advance for your help!
Wrap that bad boy in a []. It tells the parser that everything inside is the key name.
ALTER TABLE Customer DROP CONSTRAINT [PK_dbo.Customer];
Should run fine.
Personally I just wrap every identifier in brackets to avoid this exact issue. So I would write this query like this.
ALTER TABLE [Customer] DROP CONSTRAINT [PK_dbo.Customer];
I think it's more readable that way because you can instantly see identifiers.
Related
I am new to SSIS packages and just require assistance on how to transfer data from one data source onto my own database.
Below is my data flow:
Now I have a ODBC Source (Http_Requests Source) where I take data from a PostgreSQL database table (see screenshot below for table columns and data):
Below is the OLE DB destination where it has the table I want to transfer the data to (this table is currently blank):
Now I tried to start debugging to extract the data but I get a few errors (displayed below):
I am a complete novice so I would like some guidance on what I need to include in order to get this SSIS package to transfer data across. Would I need to include a merge statement and how do I apply it. I heard you can write a merge as a proc and call on the proc as a sql command. Does that mean I will need to write a proc in SSMS and then call on it within the OLE DB Destination?
If somebody can provide an example and screenshot then that would be very helpful as I am really new to SSIS.
Thank you,
Check constraint on destination table or disable them before running it.
Below are query you can use.
-- Disable all table constraints
ALTER TABLE YourTableName NOCHECK CONSTRAINT ALL
-- Enable all table constraints
ALTER TABLE YourTableName CHECK CONSTRAINT ALL
Tick keep identity
box or drop primary key on the table. After you apply the changes do not forget to refresh metadata by opening the mappings in sis.
the error means that PerformanceId is an IDENTITY column on your destination table. IDENTITY columns are read only unless you tell it otherwise. So if we were in tSQL to be able to insert IDENTITY we would turn on IDENTITY_INSERT. Because you are in SSIS you can accomplish the same thing by checking the "keep identity" box.
HOWEVER when ever you get an error like this it is usually a sign that you should NOT be mapping ID to Performance ID. The question you have to ask is the Identity from your source supposed to be the identity of the destination table? Usually not, most of the time it would be another column as a surrogate key. Then you have to understand if it is even possible. because if there is a unique constraint or primary key then the identity cannot repeat which means you have to know that your source's id column will not cause a duplicate primary key violation.
More than likely the actual fix if for you to uncheck ID from the source and ignore the value.
The column PerformanceID (in the target) is almost certainly an identity column and that is why it is not working. You may not want to transfer it (and have SQL Server generate values for PerformanceID or you can check 'Keep Identity.'
I have sql Upgrade script which has many sql statements(DDL,DML). When i ran this upgrade script in SQL developer, it runs successufully.I also provide in my script at the bottom commit. I can see all the changes in the database after running this upgrade script except the unique index constraints. When i insert few duplicate records it says unique constraint violated. It means the table has unique constraints. But i dont know why i cant view this constraints in oracle sql developer. The other DDL changes made i can view.I dont know is there any settings to view it in oracle sql developer.
CREATE UNIQUE INDEX "RATOR_MONITORING"."CAPTURING_UK1" ON "RATOR_MONITORING"."CAPTURING" ("DB_TABLE");
CREATE UNIQUE INDEX "RATOR_MONITORING_CONFIGURATION"."BRAND_UK1" ON "RATOR_MONITORING_CONFIGURATION"."BRAND" ("NAME");
CREATE UNIQUE INDEX "RATOR_MONITORING_CONFIGURATION"."BRAND_BUSINESS_PROCESS_UK1" ON "RATOR_MONITORING_CONFIGURATION"."BRAND_BUSINESS_PROCESS" ("BRAND_ID", "BP_ID");
CREATE UNIQUE INDEX "RATOR_MONITORING_CONFIGURATION"."BRAND_ENGINE_UK1" ON "RATOR_MONITORING_CONFIGURATION"."BRAND_ENGINE" ("BRAND_ID", "ENGINE_ID");
As A Hocevar noted, if you create an index
create unique index test_ux on test(id);
you see it in the Indexes tab of the table properties (not in the Constraints tab).
Please note that COMMIT is not required here, it is done implicitely in each DDL statement. More usual source of problems are stale metadata in SQL Developer, i.e. missing REFRESH (ctrl R on user or table node).
If you want to define the constraint, add following statement, that will reuse the index defined previously
alter table test add constraint test_unique unique(id) using index test_ux;
See further discussion about the option in Documentation
I am assuming you are trying to look for index on a table in the correct tab in sql developer. If you are not able to see the index there, one reason could be that your user (the one with which you are logged in) doesn't have proper rights to see the Index.
If you not obtain any error, the solution is very simple and tedious. SQL Developer doesn't refresh his fetched structures. Kindly push Refresh blue icon (or use Ctrl-R) in Connections view or disconnect and connect again (or restart SQL Developer) to see your changes in structures.
I use Access 2010 and SQL Server 2005. I am new to the process of "upsizing" which I understand is a legacy term. When I make changes to published tables, I like to localize them back into Access, alter them with the Access interface, and then "re-upsize" them to SQL Server. When I "re-uspize" an altered table Access warns me:
"A table named xxxx already exists. Do you want to overwrite it?"
I choose yes. Then Access reports an error
"Server Error 3726: Could not drop object 'xxxx' because it is
referenced by a FOREIGN KEY constraint."
I understand the importance of foreign key constraints. I have encountered this same trouble using MySQL. In MySQL I would simply set Foreign_Key_Checks = 0; before the import, then set Foreign_Key_Checks = 1; when finished.
Unfortunately in SQL Server, a table cannot be dropped while it's keys are only disabled, they must be deleted. I don't want to delete and recreate foreign keys every time I alter a table. Do I need to start altering my tables in the SQL Server environment? Is there a way to easily "Re-upsize" a table and ignore foreign Key constraints?
If you need to use Access for a front end, instead of keeping an Access DB locally and dealing with the issues of moving back and forth. Try to use Access and connect directly to a version of the sql database you can develop against directly through access. You will probably want to look into using a linked datasource in Access to SQL.
Connecting SQL Server to an Access Database
We moved our DB from an instance of SQL 2005 to a new SQL 2008r2 server. We changed the connection strings in our app to point to new database, even modified the ProviderManifestToken from 2005 to 2008. Everything was working fine until we tried to add entities from our database to our existing edmx model. I'm using the 'update model from database' wizard to add tables to the edmx diagram. The tables will appear in the diagram but only some have their associations and/or foreign keys imported. If I switch the connection string to point back to the old 2005 sql instance everything imports correctly and associations are present. I'm happy to provide additional details if necessary. I can't find a pattern to this at all. What gives?
Update: I created a new project, added an edmx, pointed it to the 2008r2 db instance, selected tables that I know have associations but the designer failed to pick up the associations. Is there something I need to install on the SQL server to get EF to work?
It's working for now. Deleting the connection string from the web.config and then using 'Update Model from Database' and going through the 'Add new connection' dialog to point to the database on the new server seemed to make it behave. If this stops working I'll post back.
Update: Turns out I had two problems. The second was that one of the tables in our DB had two nearly identical redundant indexes on the same column; a clustered PK index and a unique, non-clustered index. So any time I created a foreign key pointing to this table the database chose the unique non-clustered index to enforce the constraint (why? I don't know). But Entity Framework didn't like it and would not create or even recognize the foreign key association. I had to delete the extra non-clustered index and re-create all the foreign keys so they would point to the clustered index. Once that was done I updated my model from the database and all associations were present.
Here's the SQL query I used to check which indexes my foreign keys were using:
SELECT *
FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS C
ORDER BY CONSTRAINT_NAME
The UNIQUE_CONSTRAINT_NAME column for the FK in question should point to a clustered PK for it to work.
How did you move the database to the 2008 Server? Sounds like some or all of the relationships/constraints were not migrated. That would explain why the associations are not showing up when you point to the 2008 database.
I wanted to modify a column in a sql server 2005 table to IDENTITY(1,1)
Incidentally this table is empty and the column to be changed is a primary key.
This column is also a foreign key for two other tables.
After googling I found that you cannot use Alter table syntax to modify a column and make it an indentity column.
Link #1 : How do I add the identity property to an existing column in SQL Server
Link #2 : Adding an identity to an existing column -SQL Server
I ended up checking the dependent tables (2 of them) removing the foreign keys (generated the script from SSMS) then dropping the main table then re-creating with identity. (could try the rename option here as well)
Then re-created the foreign keys for the earlier dependent two tables.
But all this was manual work, any scripts or SPs out there to make this easier.
Ideally all these steps would be done by such a script/tool/utility:
Check dependent tables keys
Generate Create and drop foreign key scripts for this
Generate create script for the main table
drop the main table (or rename the table if the table has data)
re-create the table with identity column enabled
re-create foreign keys
You can use SSMS to generate a script (Edit a table, save script), but otherwise it's a manual process as you identified.
The SSMS scripts will pick up dependencies etc. For this kind of work, I tend to use SSMS to generate a basic script, pimp it a bit, run it carefully, then use a comparison tool (such as Red Gate compare) to generate a safer version.
Edit: The SSMS error is not an error, it's a safety check that can be switched off
(This is merely a follow-up to gbn's post with more details -- it isn't all that easy to figure this stuff out.)(
It isn't impossible to write a utility to do this, just very complex and very hard. Fortunately, Microsoft has already done it -- its called SSMS (or SMO?). To generate such a script:
In the Object Explorer, drill down to the database and table that you want to modify
Right click and select Design
Make the desired changes to the one table in the design screen. It's reasonably intuitive.
To add/remove the identity property, select the column in the upper pane, and in the lower pane/"Column Properties" tab, expand and configure the settings under "Identity Specification".
To generate a script to implement all your changes, incorporating all the dependent key changes, click on the "Generate Change Script" toolbar button. This is also an option under the "Table Designer" menu.
I also do this to generate scripts (that I later modify--SSMS doesn't always produce the most efficient code.) Once done, you can exit out without saving your changes -- leaving you a DB you can test your new script on.
drop the pk and build the same datatype column
copy the data of the column which you want to set identity to the new column.
drop the old column
reset primary key
ALTER TABLE UserRole
DROP CONSTRAINT PK_XX
ALTER TABLE XX
ADD newX int not null identity(1,1) primary key
update XX set newX = oldX
alter table XX
DROP COLUMN oldX
this is the simplest way to set identity column.
if you don't want to use the long generated script.