Ive tried to execute below delete through SQL script in Pentaho Job, I get the error as
Unknown table 'a' in MULTI DELETE. Can somebody throw light on this. Is there any other way
to go around this?
DELETE a.* FROM pm_report.PM_CONCERTS_GQV_REPORT_TEST a
WHERE EXISTS
(SELECT 1 FROM pm_report.PM_CONCERTS_GQV_REPORT_TEST_3 b WHERE b.TM_EVENT_ID=a.TM_EVENT_ID
GROUP BY b.TM_EVENT_ID)
This is mysql right?
See similar solutions here - recommends removing the table alias.
Worth noting this is nothing to do with Pentaho, if you did it in a SQL client you'd get the same error. If you don't then the difference is probably in the jdbc driver version - may be worth checking that.
i can suggest these options:
dont use aliases
try this directly on your mysql and check if it works for you.
dont use pentaho like this : make a transformation and break apart the query to steps
with table input and lookup then delete the rows by row_id
its a little bit longer but a lot more undersrandable and easy to maintain.
"dont over optimize"
Related
I want to modify a column name to new name present in a table
but here problem i want to manually modify the column name present in Triggers or SP's.
Is there a any better way of doing it.
To rename a column am using this
sp_RENAME 'Tablename.old_Column', 'new_column' , 'COLUMN';
similarly how can i do it for triggers or SP's.? without opening each script?
Well, there are a bunch of 3rd party tools that are promising this type of "safe rename", some for free and some are not:
ApexSQL has a free tool for that, as MWillemse wrote in his answer,
RedGate have a commercial tool called SQLPrompt that also have a safe renaming feture, However it is far from being free.
Microsoft have a visual studio add-in called SQL Server Data Tools (or SSDT in the short version), as Dan Guzman wrote in his comment.
I have to say I've never tried any of these specific tools for that specific task, but I do have some experience with SSDT and some of RedGate's products and I consider them to be very good tools. I know nothing about ApexSQL.
Another option is to try and write the sql script yourself, However there are a couple of things to take into consideration before you start:
Can your table be accessed directly from outside the sql server? I mean, is it possible that some software is executing sql statement directly on that table? If so, you might break it when you rename that column, and no sql tool will help in this situation.
Are your sql scripting skills really that good? I consider myself to be fairly experienced with sql server, but I think writing a script like that is beyond my skills. Not that it's impossible for me, but it will probably take too much time and effort for something I can get for free.
Should you decide to write it yourself, there are a few articles that might help you in that task:
First, Microsoft official documentation of sys.sql_expression_dependencies.
Second, an article called Different Ways to Find SQL Server Object Dependencies that is written by a 13 years experience DBA,
and last but not least, a related question on StackExchange's Database Administrator's website.
You could, of course, go with the safe way Gordon Linoff suggested in his comment, or use synonyms like destination-data suggested in his answer, but then you will have to manually modify all of the columns dependencies manually, and from what I understand, that is what you want to avoid.
Renaming the Table column
Deleting the Table column
Alter Table Keys
Best way use Database Projects in Visual Studio.
Refer this links
link 1
link 2
you can do what #GorDon suggested.
Apart from this,you can also play with this query,
select o.name, sc.* from sys.syscomments sc inner join sys.objects o
on sc.id=o.object_id where sc.text like '%oldcolumnname%'
this will return list of all proc and trigger.Also you can modify filter to get exact list.then it will be very easy for you to modify,manually.
But whatever you decide,don't simply drop old column.
To be safe,even keep back up.
This suggestion relates to Oracle DB, however there may be equivalent solutions in other DBMS's.
A temporary solution to your issue is to create a pseudocolumn. This solution looks a little hacky because the syntax for a pseudocolumn requires an expression. The simplest expression I can think of is the case statement below. Let me know if you can make it more simple.
ALTER TABLE <<tablename>> ADD (
<<new_column_name>> AS (
CASE
WHEN 1=1 THEN <<tablename>>.<<old_column_name>>
END)
);
This strategy basically creates a new column on the fly by evaluating the case statement and copying the value of <<old_column_value>> to <<new_column_value>>. Because you are dynamically interpolating this column there is a performance penalty vs just selecting the original column.
The one gotcha is that this will only work if you are duplicating a column once. Multiple pseudocolumns cannot contain duplicate expressions in Oracle.
The other strategy you can consider is to create a view and you can name the columns whatever you want. You can even INSERT/UPDATE/DELETE (execute DML) against views, but this would give you a whole new table_name, not just a new column. You could however rename the old table, and name your view the same as your old table. This also has a performance penalty vs just accessing the underlying table.
You might want to replace that text in definition. However, you will be needing a dedicated administrator connection in sql server. Versions also vary in setting up a dedicated administrator connection. Setting up the startup parameter by adding ;-T7806 under advanced. And by adding Admin: before the servername upon logging in. By then, you may be able to modify the value of the definition.
I have used mysql for some projects and recently I moved to postgresql. In mysql when I alter a table or a field the corresponding query will be displayed in the page. But such a feature was not found in postgresql(kindly excuse me if I'm wrong). Since the query was readily available it was very helpful for me to test something in the local database(without explicitly typing the query), copy the printed query and run it in the server. Now it seems like I've to manually do all the trick. Even though I'm familiar with the query operations,at times it can be pretty time consuming process. Can anybody help me? How can I get the corresponding query to get displayed in postgresql(like in mysql) whenever a change is made to the table?
If you use SELECT * FROM ... there should not be any reason for your output to not include newly added columns, no matter how you get your results - would that be psql in command line, PgAdmin3 or any other IDE.
After you add new columns, it is possible that these changes are still in open transaction in other window or SQL command - be sure to COMMIT such transaction. Note that your changes to data or schema will not be visible to any other database clients until transaction commits.
If your IDE still does not show changes, maybe you need to refresh list of tables or if that option is not available, restart your IDE. If that does not work still, maybe you should use better IDE.
If you have used SELECT field1, field2, ... FROM ... then you must add new fields into your SELECT statement(s) - but this would be true for any other SQL implementation, MySQL included.
You could use the LISTEN / NOTIFY mechanism in PostgreSQL to notify your client on altering the database schema.
select orderid from orders where REGEXP_REPLACE(orderid,'/^0+(.)/')
I have searched the documentation and am missing it. If I run this query will it change any real data or just my set returned for output (the "virtual" data)? The word replace scares me. I am using oracle 11g.
Thank you.
Because you are performing a SELECT, you end up getting a read only view of the data, nothing has changed.
So you don't need to worry about running this select statement. The only way to update it would be to follow this up with an UPDATE command.
No, it doesn't. (even though this answer is too short for SO).
I'm working in Ubuntu with MySql and I also have Query Browser and Administrator installed, I'm not afraid of the command line either if it helps.
I want simply to be able to run a query and see a result set but then convert that result set into a series of commands that could be used to create the same rows in a table of an identical schema.
I hope the question makes sense, it's quite a simple problem and one that must have been solved but I can't for the life of me work out where this kind of conversion is made available.
Thanks in advance,
Gav
I think you need to use a command line utility mysqldump http://dev.mysql.com/doc/refman/5.1/en/mysqldump.html
if you want to dump one or more tables.
If you need to dump a result of an arbitrary query and restore it later, take a look on SELECT ... INTO OUTFILE and LOAD DATA INFILE( http://dev.mysql.com/doc/refman/5.0/en/load-data.html)
I do not know if I understood you at all but you can use a SELECT INTO statement.
SELECT *
INTO new_table_name
FROM old_tablename
WHERE ...
I'm trying to pull user data from 2 tables, one locally and one on a linked server, but I get the wrong results when querying the remote server.
I've cut my query down to
select * from SQL2.USER.dbo.people where persId = 475785
for testing and found that when I run it I get no results even though I know the person exists.
(persId is an integer, db is SQL Server 2000 and dbo.people is a table by the way)
If I copy/ paste the query and run it on the same server as the database then it works.
It only seems to affect certain user ids as running for example
select * from SQL2.USER.dbo.people where persId = 475784
works fine for the user before the one I want.
Strangely I've found that
select * from SQL2.USER.dbo.people where persId like '475785'
also works but
select * from SQL2.USER.dbo.people where persId > 475784
brings back records with persIds starting at 22519 not 475785 as I'd expect.
Hope that made sense to somebody
Any ideas ?
UPDATE:
Due to internal concerns about doing any changes to the live people table, I've temporarily moved my database so they're both on the same server and so the linked server issue doesn't apply. Once the whole lot is migrated to a separate cluster I'll be able to investigate properly. I'll update the update once this happens and I can work my way through all the suggestions. Thanks for your help.
The fact that LIKE operates is not a major clue: LIKE forces integers to string (so you can say WHERE field LIKE '2%' and you will get all records that start with a 2, even when field is of integer type). Your incorrect comparisons would lead me to think your indexes are corrupt, but you say they work when not used via the link... however, the selected index might be different depending on the use? (I seem to recall an instance when I had duplicate indexes and only one was stale, although that was too long ago to recall the exact cause).
Nevertheless, I would try rebuilding your index using the DBCC DBREINDEX (tablenname) command. If it turns out that doing so fixes your query, you may want to rebuild them all: here is a script for rebuilding them all easily.
Is dbo.people a table or a view? I've seen something similar where the underlying table schema had been changed and dropping and recreating the view fixed the problem, although the fact that the query works if run directly on the linked server does indicate something index based..
Is the linked server using the same collation? Depending on the index used, I could see something like this perhaps happening if the servers were not collation compatible, but the linked server was set up with collation compatible (which tells Sql Server it can run the query on the remote server).
I would check the following:
Check your definition on the linked server, and confirm that SQL2 is the
server you expect it to be
Check and compare the execution plans both from the remote and local servers
Try linking by IP address rather than name, to ensure you have the proper machine
Put the code into a stored procedure on the remote machine, and try calling that instead
Sounds like a bug to me - I;ve read of some issues along these lines, btu can't remember specifically what. What version of SQL Server are you running?
select * from SQL2.USER.dbo.people where persId = 475785
for a PersID which fails how does:
SELECT *
FROM OpenQuery(SQL2, 'SELECT * FROM USER.dbo.people WHERE persId = 475785')
behave?