Can anybody help me with this?
I prefer if I don't have to explicitly list the table names.
Saw this before...
exec sp_MSforeachtable "DROP TABLE ? PRINT '? to be dropped' "
Source - http://sqlserver-qa.net/blogs/t-sql/archive/2008/05/20/4266.aspx
How about dropping the database? DROP DATABASE <database name>
Of course, that's rough on stored procedures, triggers, etc. But if the purpose is to eliminate all the tables in order to recreate them, it makes sense that you'd recreate all the other associated components as well, such as indexes.
Related
I am looking to set up a high availability architecture whereby two mirror databases exist (DB1 & DB2) that serve another database with views (DBV) on it. DB1 has the overnight ETL on it, whilst DBV looks at DB2 until the etl is complete on DB1, at which point its views switch to the underlying tables on DB1. Once the ETL is complete on DB1, DB2 is restored with DB1 data before the next day's ETL. The next day, DB1 and DB2 switch roles.
I am looking for a neater/more secure way of switching between the two views than running sp_executesql to run a dynamically built string. I will be looking to also do this on stored procedures from a staging database which need to have their scripts dynamically altered to use the correct database to run the ETL on. Essentially, I am looking to pass the USE statement dynamically and then execute the rest of the script outside of any dynamic statement.
I want to avoid sp_executesql for support reasons for other developers and also to get around any possible extensive concatenation of strings if the stored procedure/view gets particularly lengthy.
Any ideas / different approaches to high availability in this context would be welcome.
One option might be to create a copy of each view in DBV for both target databases - i.e.
some_schema.DB1_myview
some_schema.DB2_myview
and then use a synonym to expose the views under their final names.
CREATE SYNONYM some_schema.myview ON some_schema.DB1_myview
Your switch process would then need only to drop and recreate the synonyms, rather than the views themselves. This would still need to be done with a dynamic SQL statement, but the complexity would be much lower.
A downside would be that there would be a risk of the definitions of the underlying views getting out of sync.
Edit
At the cost of more risk of getting out of sync, it would be possible to avoid dynamic SQL altogether by creating (for instance) a pair of stored procedures each of which generated the synonyms for one database or the other. Your switch code would then only need to work out which procedure to call.
Have you considered renaming the databases as you switch things around? I.e. the following prints 1 followed by 2, nothing in DBV had to be modified:
create database DB1
go
use DB1
go
create table T (ID int not null);
insert into T(ID) values (1);
go
create database DB2
go
use DB2
go
create table T (ID int not null);
insert into T(ID) values (2);
go
create database DBV
go
use DBV
go
create view V
as
select ID
from DB1..T
go
select * from V
go
alter database DB1 modify name = DBt
go
alter database DB2 modify name = DB1
go
alter database DBt modify name = DB2
go
select * from V
Obviously better names than 1 and 2 may be used. This way, DB1 is always the one used for live and DB2 is used for any staging work.
I have a database which consist of 300 tables with data in it. I need to delete all the data inside each tables. I tried to truncate all tables but then I got an error that the process could not be completed because one of the column in a table is a foreign key. Is there other way to resolve my problem? Thanks.
You need to either:
remove all the foreign keys, truncate, then re-create FKs;
disable all the foreign keys, delete (not truncate), then re-enable FKs; or,
delete from child tables first.
The latter may not be possible if you're lucky enough to have circular references, and it can still be complicated even without circular references. The first two are also relatively complex, but I solved a very similar problem for a different user recently (and I find these easier than trying to determine the proper delete order):
Temporarily disable all foreign key constraints
Another idea is to perform a simpler and more complete wipe:
script the tables (and other objects obviously), drop the database and re-create it; or,
create a copy of the database, and use Visual Studio / SSDT or a 3rd party schema comparison tool to create all of the objects in the empty database (then you can drop the old database and rename the new one).
Try this : A quick way of doing it .sp_msforeachtable is an undocumented SP so there's a risk in using them. I came up with this answer using Aaron Logic by disabling the constraints used in his answer.
use [YourDB]
Go
EXEC sp_MSForEachTable 'ALTER TABLE ? NOCHECK CONSTRAINT ALL'
EXEC sp_MSForEachTable 'Truncate Table ?'
EXEC sp_MSForEachTable 'ALTER TABLE ? CHECK CONSTRAINT ALL'
How can I truncate all tables of a database?
Why would you want to truncate all tables? If you want an empty database, why not run the CREATE script of the database?
If you want to Truncate a table referenced by a foreign key, you will have to drop the FK constraint first. Disabling constraints is something that is not possible anymore in recent versions of SQL Server.
You can see this post : how-do-you-truncate-all-tables-in-a-database-using-tsql
I use the script
EXEC sp_MSForEachTable 'ALTER TABLE ? NOCHECK CONSTRAINT ALL'
EXEC sp_MSForEachTable 'DELETE FROM ?'
EXEC sp_MSForEachTable 'ALTER TABLE ? CHECK CONSTRAINT ALL'
GO
Reset Auto-Increment? I'm not sure if you understand correctly how this works.
Primary Key incrementing is handled by SQL Server using the IDENTITY specification. If your tables have got no data in them, it will always start from 0.
If I were you, I'd go have a flick through your programming books and pick up some basic database knowledge as it sounds like you're missing some fundamental facts there.
I have an application that uses a SQL Server database with several instances of the database...test, prod, etc... I am making some application changes and one of the changes involves changing a column from a nvarchar(max) to a nvarchar(200) so that I can add a unique constraint on it. SQL Server tells me that this requires dropping the table and recreating it.
I want to put together a script that will do the table drop, recreate it with the new schema, and then reinsert the data that was there previously all in one go, if possible, just to keep things simple for use when I migrate this change to production.
There is probably a good SQL Server way to do this but I'm just not aware of it. If I was using Mysql I would mysqldump the table and its contents, and use that as my script for applying that change to production. I can't find any export functionality in SQL server that will give me a text file consisting of inserts for all data in a table.
Use SQL Server's Generate Scripts command
right click on the database; Tasks -> Generate Scripts
select your tables, click Next
click the Advanced button
find Types of data to script - choose Schema and Data.
you can then choose to save to file, or put in new query window.
results in INSERT statements for all table data selected in bullet 2.
No need to script
here are two ways
1 use alter table ....alter column.....
example..you have to do 1 column at a time
create table Test(SomeColumn nvarchar(max))
go
alter table Test alter column SomeColumn nvarchar(200)
go
2 dump into a new table while converting the column
select <columns except for the columns you want to change>,
convert(nvarchar(200),YourColumn) as YourColumn
into SomeNewTable
from OldTable
drop old table
rename this table to the same table as the old table
EXEC sp_rename 'SomeNewTable', 'OldTable';
Now add your index
How can I perform this query on whatever way:
delete from sys.tables where is_ms_shipped = 0
What happened is, I executed a very large query and I forgot to put USE directive on top of it, now I got a zillion tables on my master db, and don't want to delete them one by one.
UPDATE: It's a brand new database, so I don't have to care about any previous data, the final result I want to achieve is to reset the master db to factory shipping.
If this is a one-time issue, use SQL Server Management Studio to delete the tables.
If you must run a script very, very carefully use this:
EXEC sp_msforeachtable 'DROP TABLE ?'
One method I've used in the past which is pretty simple and relatively foolproof is to query the system tables / info schema (depending on exact requirements) and have it output the list of commands I want to execute as the results set. Review that, copy & paste, run - quick & easy for a one-time job and because you're still manually hitting the button on the destructive bit, it's (IMHO) harder to trash stuff by mistake.
For example:
select 'drop table ' + name + ';', * from sys.tables where is_ms_shipped = 0
No backups? :-)
One approach may be to create a Database Project in Visual Studio with an initial Database Import. Then delete the tables and synchronize the project back to the database. You can do the deletes en masse with this approach while being "buffered" with a commit phase and UI.
I am fairly certain the above approach can be used to take care of the table relationships as well (although I have not tried in the "master" space). I would also recommend using a VS DB project (or other database management tool that allows schema comparing and synchronization) to make life easier in the future as well as allowing version-able (e.g. with SCM) schema change-tracking.
Oh, and whatever is done, please create a backup first. If nothing else, it is good training :-)
Simplest and shortest way I did was this:
How to Rebuild System Databases in SQL Server 2008
The problem with all other answers here is that it doesn't work, since there are related tables and it refuses to execute.
This one, not only it works but actually is what I am looking for: "Reset to factory defaults" as stated in the question.
Also this one will delete everything, not only tables.
This code could be better but I was trying to be cautious as I wrote it. I think it is easy to follow an easy to tweak for testing before you commit to deleting your tables.
DECLARE
#Prefix VARCHAR(50),
#TableName NVARCHAR(255),
#SQLToFire NVARCHAR(350)
SET #Prefix = 'upgrade_%'
WHILE EXISTS(
SELECT
name
FROM
sys.tables
WHERE
name like #Prefix
)
BEGIN
SELECT
TOP 1 --This query only iterates if you are dropping tables
#TableName = name
FROM
sys.tables
WHERE
name like #Prefix
SET #SQLToFire = 'DROP TABLE ' + #TableName
EXEC sp_executesql #SQLToFire;
END
I did something really similar, and what I wound up doing was using the Tasks--> script database to only script drops for all the database objects of the originally intended database. Meaning the database I was supposed to run the giant script on, which I did run it on. Be sure to include IF Exists in the advanced options, then run that script against the master and BAM, deletes everything that exists in the original target database that also exists in the master, leaving the differences, which should be the original master items.
Not very elegant but as this is a one time task.
WHILE EXISTS(SELECT * FROM sys.tables where is_ms_shipped = 0)
EXEC sp_MSforeachtable 'DROP TABLE ?'
Works fine on this simple test (clearing a on the second loop after failing on the first attempt and proceeding onwards to delete b)
create table a
(
a int primary key
)
go
create table b
(
a int references a (a)
)
insert into a values (1)
insert into b values (1)