I started to learn Java a month ago.
Today I was studying some SQL phrases which are necessary for creating websites using JSP and Servlets.
I used SQL Developer and JDBC.
After doing some insert/delete/update manipulation, I accidentally clicked on 'commit' instead of 'roll back'.
So some of my data in certain tables are lost and so am I...
I think I must delete and re-install JDBC to have all the basic data that Oracle offers.
But I'd like to ask for some help here before doing that, if there is any simpler way.
Can anyone help me please?
Thank you in advance.
I am not sure if it will help but here is the SQL I used:
INSERT INTO DEPARTMENTS VALUES(280, 'DataAnalytics', null, 1700);
INSERT INTO DEPARTMENTS (DEPARTMENT_ID, DEPARTMENT_NAME, MANAGER_ID,
LOCATION_ID) VALUES(280, 'DataAnalytics', null, 1700);
UPDATE emps SET SALARY=30000WHEREEMPLOYEE_ID=101;
UPDATE EMPS SET (JOB_ID, SALARY, MANAGER_ID)= (SELECT JOB_ID, SALARY,
MANAGER_ID FROM EMPS WHERE EMPLOYEE_ID=108) WHERE EMPLOYEE_ID=109;
DELETE FROM EMPS WHERE EMPLOYEE_ID=108; DELETE FROM EMPLOYEES WHERE
EMPLOYEE_ID=103;
I think you may be confusing JDBC with SQL. JDBC is short for Java Database Connectivity, and it's a Java standard used to connect from Java to relational databases (See Oracle's documentation on JDBC here: https://docs.oracle.com/en/database/oracle/oracle-database/18/jjdbc/introducing-JDBC.html#GUID-864DB502-5E50-4044-8132-33D6AAF8927A). Depending on what version of the Oracle Database you're running, the JDBC driver version, and which client you're using, you may find that you are missing some functionality, but that functionality is probably completely separate from the SQL you ran.
When you use SQL Developer to connect, you may be using a JDBC connection, but in all likelihood, you are using either a Basic or TNS Connection Type. Those do not rely on JDBC. The SQL you ran from SQL Developer modified the data because that's what SQL is used for. SQL is short for Structured Query Language, and it's widely used to manage data in relational databases.
By using SQL Developer, you should have access to all of the standard functionality that Oracle has to offer. You may be missing some features, but that is completely normal if you or your organization does not have a licensing agreement with Oracle and have not configured those features. Reinstalling JDBC won't change that.
What are you trying to accomplish? If you want to restore your data, JDBC has nothing to do with that. You will have to either: 1. Flashback the database or table (depending on which version of Oracle you're running,) which will restore the database (or the relevant object(s)) back to a specific point in time before you executed those SQL commands. 2. Use OEM or RMAN to restore the database to a time before you executed those SQL commands, or 3. Delete the relevant data and re-create (or re-import) your data.
Since you committed the transaction to manipulate that data, these are likely going to be your only options to restore the database how it was. If you know the original values that belong in those tables, I suppose that you could also write up more SQL to change the values back to the original. This may result in your desired outcome, but be forewarned that this method (and option #3) would not be considered a restore, and all of the changes that you made up to that point would still be apart of the transaction history. If that doesn't matter, that may be the easiest route for you to pursue.
Related
I want to create a SQL script to populate a DEV database using INSERT statements. (Preferably using INSERT statements, rather than binary form, so that I can safely check-in the script to version control).
I can easily extract the INSERT statements using various tools. But I haven't found a way to extract the INSERT statements in an order so that when run, FK constraints will not be violated.
I've used SQL Server tools which accomplish this. e.g. RedGate. But cannot seem to find a Sybase compatible method.
I am using Sybase ASE
Any advice would be appreciated.
Here at Redgate we don't often get Sybase requests and there are few vendors who produce tools for this market. You could try DBBest, who specialize in breadth of RDBMS support.
I just used the SQLAzureMW (SQL Azure Migration Wizard Tool) to migrate my SQL Server database to Azure SQL. It went off without a hitch - all my tables are there, the website is running fine off it, etc.
Here's what's odd: if I execute a simple SELECT statement against my tables, I get only a few of the rows. I assumed they were missing, but my website is using some of those records as if they're there. So I queried with a WHERE clause and BAM - they showed up. How the... what the... why isn't my select showing me everything? This applies to many of the tables I've tested.
SQL Azure
On-Premise
I gave up on MS SQL Management Studio and am instead using SQL Server Object Explorer from Visual Studio 2012/2013. It functions properly and allows inline editing of data.
Consider this SELECT statement:
SELECT
SvcTimeID,
LoginName,
MeanSeconds,
MedianSeconds,
RequestCount,
StdDevSeconds,
SvcDate,
CAST (TS AS INT) AS TS
FROM dbo.SvcTime
WHERE SvcDate >= #SvcDate
Where the parameter is set:
cmd.Parameters["#SvcDate"].Value = DateTime.UtcNow - new TimeSpan(31, 0, 0, 0);
Execute that statement in an Azure Web Role - brought back, say 24 rows.
Now, insert two new rows; wait at least one minute; execute the statement again. Do the recently inserted rows appear? In my case, they did not. Note: the default value of SvcDate in the database is getutcdate().
Move the SQL Azure database from the web edition to the standard (S2) edition. Rows magically appear.
Here is my theory. The issue you had was not with MS SQL Management Studio but with SQL Azure itself where, under certain circumstances, the same query will return the original rows from a cache someplace and will miss the new rows in the database.
This has blown any remaining confidence I had with Azure.
I was scared at first, but I think this has an explanation:
If you inserted some rows in connection "A" and can't find them in other sessions, maybe you have a uncommited transaction. By default, in SQL Server on premise, your second connections would hung until transaction is commited or rolled back. (Isolation level read committed)
Somehow, using the same isolation level, Azure acts differently. I seems to work in some cases as a snapshot isolation. Because of that, you can read from the table, but results are not updated. Or maybe the lock are set in a different way.
To solve this, check sysprocesses for sessions with open_tran > 0 or just be careful commmiting trans. In the example, running commit in your session "A" should do it.
Good luck!
i want to extract specific database tables & stored procedures into one master script. Do you know any software that can help me do this faster? I've tried using the SQL Database publishing tool, but it's not that efficient since its gathering tables that I didn't select.
In SQL Server 2005, right click on the database, then select Tasks, and then select Generate Scripts.
Generating SQL Scripts in SQL Server 2005
As mentioned in that link, I'm fairly sure you have to generate the DROP and CREATE statements separately.
Try DBSourceTools. http://dbsourcetools.codeplex.com
Its open source, and specifically designed to script databases - tables, views, procs to disk.
It also allows you to select which tables, views, db-objects to script.
I use Redgate SQL compare for this (by comparing to an empty DB), as well as for doing upgrades between all my DB versions (I save a copy of the DB for each released version, and then just do a compare between current and previous to get a change script for that version).
I have found the "Generate Scripts" does a bad job in some cases with dependencies - eg, it will try to create a stored procedure that uses a table before the table is created, causing the script to fail. I'll accept I'm possibly using it wrong, but SQL Compare "just works". The scripts it generates are also enclosed in a transaction -- so if something fails, the whole change is rolled back. You don't end up with a half-populated or half-upgraded database.
Downside is that this is a commercial tool, but IMHO worth the money.
I'm looking for a way to validate the SQL schema on a production DB after updating an application version. If the application does not match the DB schema version, there should be a way to warn the user and list the changes needed.
Is there a tool or a framework (to use programatically) with built-in features to do that?
Or is there some simple algorithm to run this comparison?
Update: Red gate lists "from $395". Anything free? Or more foolproof than just keeping the version number?
Try this SQL.
- Run it against each database.
- Save the output to text files.
- Diff the text files.
/* get list of objects in the database */
SELECT name,
type
FROM sysobjects
ORDER BY type, name
/* get list of columns in each table / parameters for each stored procedure */
SELECT so.name,
so.type,
sc.name,
sc.number,
sc.colid,
sc.status,
sc.type,
sc.length,
sc.usertype ,
sc.scale
FROM sysobjects so ,
syscolumns sc
WHERE so.id = sc.id
ORDER BY so.type, so.name, sc.name
/* get definition of each stored procedure */
SELECT so.name,
so.type,
sc.number,
sc.text
FROM sysobjects so ,
syscomments sc
WHERE so.id = sc.id
ORDER BY so.type, so.name, sc.number
I hope I can help - this is the article I suggest reading:
Compare SQL Server database schemas automatically
It describes how you can automate the SQL Server schema comparison and synchronization process using T-SQL, SSMS or a third party tool.
You can do it programatically by looking in the data dictionary (sys.objects, sys.columns etc.) of both databases and comparing them. However, there are also tools like Redgate SQL Compare Pro that do this for you. I have specified this as a part of the tooling for QA on data warehouse systems on a few occasions now, including the one I am currently working on. On my current gig this was no problem at all, as the DBA's here were already using it.
The basic methodology for using these tools is to maintain a reference script that builds the database and keep this in version control. Run the script into a scratch database and compare it with your target to see the differences. It will also generate patch scripts if you feel so inclined.
As far as I know there's nothing free that does this unless you feel like writing your own. Redgate is cheap enough that it might as well be free. Even as a QA tool to prove that the production DB is not in the configuration it was meant to be it will save you its purchase price after one incident.
You can now use my SQL Admin Studio for free to run a Schema Compare, Data Compare and Sync the Changes. No longer requires a license key download from here http://www.simego.com/Products/SQL-Admin-Studio
Also works against SQL Azure.
[UPDATE: Yes I am the Author of the above program, as it's now Free I just wanted to Share it with the community]
If you are looking for a tool that can compare two databases and show you the difference Red Gate makes SQL Compare
You didn't mention which RDMBS you're using: if the INFORMATION SCHEMA views are available in your RDBMS, and if you can reference both schemas from the same host, you can query the INFORMATION SCHEMA views to identify differences in:
-tables
-columns
-column types
-constraints (e.g. primary keys, unique constraints, foreign keys, etc)
I've written a set of queries for exactly this purpose on SQL Server for a past job - it worked well to identify differences. Many of the queries were using LEFT JOINs with IS NULL to check for the absence of expected items, others were comparing things like column types or constraint names.
It's a little tedious, but its possible.
I found this small and free tool that fits most of my needs.
http://www.wintestgear.com/products/MSSQLSchemaDiff/MSSQLSchemaDiff.html
It's very basic but it shows you the schema differences of two databases.
It doesn't have any fancy stuff like auto generated scripts to make the differences to go away and it doesn't compare any data.
It's just a small, free utility that shows you schema differences :)
Make a table and store your version number in there. Just make sure you update it as necessary.
CREATE TABLE version (
version VARCHAR(255) NOT NULL
)
INSERT INTO version VALUES ('v1.0');
You can then check the version number stored in the database matches the application code during your app's setup or wherever is convenient.
SQL Compare by Red Gate.
Which RDBMS is this, and how complex are the potential changes?
Maybe this is just a matter of comparing row counts and index counts for each table -- if you have trigger and stored procedure versions to worry about also then you need something more industrial
Try dbForge Data Compare for SQL Server. It can compare and sync any databases, even very large ones. Quick, easy, always delivers a correct result.
Try it on your database and comment upon the product.
We can recommend you a reliable SQL comparison tool that offer 3 time’s faster comparison and synchronization of table data in your SQL Server databases. It's dbForge Data Compare for SQL Server.
Main advantages:
Speedier comparison and synchronization of large databases
Support of native SQL Server backups
Custom mapping of tables, columns, and schemas
Multiple options to tune your comparison and synchronization
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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)