So a little background on our system to explain things.
Our databases are version (as probably most are). We have a table in the database called "DBVersion". However a few months ago we migrated over to liquibase. And now have a DATABASECHANGELOG table.
We, unfortunately, are a fairly unorganized company when it comes to our databases. So I am trying to write a view that will allow me to know what version our clients are on.
I honestly dont even know where to begin. But I figured I can write multiple CASE statements that will allow me to do this. I will be using the SP sp_msforeachdb to run the view.
SELECT
Case when id = '8.12' then '8.12'
End as Version
From DATABASECHANGELOG
Where id = '8.12'
I would like to do something like this:
CASE
WHEN (SELECT ID FROM DATABASECHANGELOG WHERE ID = '8.12' IF NULL CONTINUE)
WHEN (SELECT VERSION FROM DBVERSION, IF > 400 && < 425 THEN PRINT 'VERSION 8.7'
I know the above query isnt even in SQL, But It gives you an idea. Our versions with Liquibase are 8.10, 8.11, and 8.12 plus all future version. Everything below 8.10 is with the watson version which would be a simple number range.
Sorry if this is way too confusing.
Don't really understand your question.
The following SQL displays your application's database versions:
SELECT ID,FILENAME,TAG FROM DATABASECHANGELOG WHERE TAG IS NOT NULL
Each time you run the "tag" command it will insert a value into the tag column, so that a rollback operation knows how many changesets to undo.
Related
So I'm kind of stumped.
I have a MySql project that involves a database table that is being manipulated and altered by scripts on a regular basis. This isn't so unusual, but I need to automate a script to run (after hours, when changes aren't happening) that would save the result of the following:
SHOW CREATE TABLE [table-name];
This command generates the ready-to-run script that would create the (empty) table in it's current state.
In SqlWorkbench and Navicat it displays the result of this SHOW command in a field in a result set, as if it was the result of a SELECT statement.
Ideally, I want to take into a variable in a procedure, and change the table name; adding a '-mm-dd-yyyy' to end of it, so I could show the day-to-day changes in the table schema on an active server.
However, I can't seem to be able to do that. Unlike a Select result set, I can't use it like that. I can't get it in a variable, or save it to a temporary, or physical table or anything. I even tried to return this as a value in a function, from which I got the error that a function cannot return a result set - which explains why it's displayed like one in the db clients.
I suspect that this is a security thing in MySql? If so, I can totally understand why and see the dangers exposed to a hacker, but this isn't a public-facing box at all, and I have full root/admin access to it. Hopefully somebody has already tackled this problem before.
This is on MySql 8, btw.
[Edit] After my first initial comments, I need to add; I'm not concerned about the data with this question whatsoever, but rather just these schema changes.
What I'd really -like- to do is this:
SELECT `Create Table` FROM ( SHOW CREATE TABLE carts )
But this seems to be mixing apples and oranges, as SHOW and SELECT aren't created equal, although they both seem to return the same sort of object
You cannot do it in the MySQL stored procedure language.
https://dev.mysql.com/doc/refman/8.0/en/show.html says:
Many MySQL APIs (such as PHP) enable you to treat the result returned from a SHOW statement as you would a result set from a SELECT; see Chapter 29, Connectors and APIs, or your API documentation for more information. In addition, you can work in SQL with results from queries on tables in the INFORMATION_SCHEMA database, which you cannot easily do with results from SHOW statements. See Chapter 26, INFORMATION_SCHEMA Tables.
What is absent from this paragraph is any mention of treating the results of SHOW commands like the results of SELECT queries in other contexts. There is no support for setting a variable to the result of a SHOW command, or using INTO, or running SHOW in a subquery.
So you can capture the result returned by a SHOW command in a client programming language (Java, Python, PHP, etc.), and I suggest you do this.
In theory, all the information used by SHOW CREATE TABLE is accessible in the INFORMATION_SCHEMA tables (mostly TABLES and COLUMNS), but formatting a complete CREATE TABLE statement is a non-trivial exercise, and I wouldn't attempt it. For one thing, there are new features in every release of MySQL, e.g. new data types and table options, etc. So even if you could come up with the right query to produce this output, in a couple of years it would be out of date and it would be a thankless code maintenance chore to update it.
The closest solution I can think of, in pure MySQL, is to regularly clone the table structure (no data), like so:
CREATE TABLE backup_20220618 LIKE my_table;
As far as I know, to get your hands on the full explicit CREATE TABLE statement, as a string, would require the use of an external tool like mysqldump which was designed specifically for that purpose.
I'm a java dev who uses Mysql Workbench as a database client and IntelliJ IDEA as an IDE. Every day I do SQL queries to the database from 5 up to 50 times a day.
Is there a convenient way to save and re-run frequently used queries in Mysql Workbench/IntelliJ IDEA so that I can:
avoid typing a full query which has already been used again
smoothly access a list of queries I've already used (e.g by auto-completion)
If there is no way to do it using Mysql Workbench / IDEA, could you please advise any good tools providing this functionality?
Thanks!
Create Stored Procedures, one per query (or sequence of queries). Give them short names (to avoid needing auto-completion).
For example, to find out how many rows in table foo (SELECT COUNT(*) FROM foo;).
One-time setup:
DELIMITER //
CREATE PROCEDURE foo_ct
BEGIN;
SELECT COUNT(*) FROM foo;
END //
DELIMITER ;
Usage:
CALL foo_ct();
You can pass arguments in in order to make minor variations. Passing in a table name is somewhat complex, but numbers of dates, etc, are practical and probably easy.
If you have installed SQLyog for your mysql then you can use Favorites menu option in which you can save your query and in one click it will automatically writes the saved query on Query Editor.
The previous answers are correct - depending on the version of the Query Browser they are either called Favorites or Snippets - the problem being you can't create sub-folders to group them. And keeping tabs open is an option - but sometimes the browser 'dies' - and you're back to ground 0. So the obvious solution I came up with - create a database table! I have a few 'metadata' fields for descriptions - the project a query is associated to; problem the query solves; and the actual query.
You could keep your query library in an SQL file and load that when WB opens (it's automatically opened when you restart WB and that file was open on last close). When you want to run a specific query place the caret in it's text and press Ctrl+Enter (Cmd+Enter on Mac) to run only this query. The organization of that SQL file is totally up to you. You have more freedom than any "favorites" solution can give you. You can even have more than one file with grouped statements.
Additionally, MySQL Workbench has a query history (see the Output Tab), which is saved to disk, so you can return to a query even month's after you wrote it.
I use Kettle for some transformations and ran into a problem:
For one specific row, my DatabaseLookup step hangs. It just doesn't give a result. Trying to stop the transformation results in a never ending "Halting" for the lookup step.
The value given is nothing complicated at all, neither it is different from all other rows/values. It just won't continue.
Doing the same query in the database directly or in a different database tool (e.g. SQuirreL), it works.
I use Kettle/Spoon 4.1, the database is MySQL 5.5.10. It happens with Connector/J 5.1.14 and the one bundled with spoon.
The step initializes flawlessly (it even works for other rows) and I have no idea why it fails. No error message in the Spoon logs, nothing on the console/shell.
weird. Whats the table type? is it myisam? Does your transform also perform updates to the same table? maybe you are locking the table inadvertantly at the same time somehow?
Or maybe it's a mysql 5.5 thing.. But ive used this step extensively with mysql 5.0 and pdi 4.everything and it's always been fine... maybe post the transform?
I just found the culprit:
The lookup takes as a result the id field and gave it a new name, PERSON_ID. This FAILS in some cases! The resulting lookup/prepared statement was something like
select id as PERSON_ID FROM table WHERE ...
SOLUTION:
Don't use underscore in the "New name" for the field! With a new name of PERSONID everything works flawlessly for ALL rows!
Stupid error ...
Does anyone know of a way to embed comments in MySQL statements? When I search for mysql and comments I get only ways to put comments in tables, etc
The idea, if I implement this the way my boss wants it, is to prepend the user id to the statement apparently so that when MySQL is analyzed later (via the binary log) we know who did what.
Example:
SELECT id
FROM customer
WHERE handle='JBH'
Would now show up as:
-- user:jwilkie
SELECT id
FROM customer
WHERE handle='JBH'
(or similar)
EDIT FOR CLARITY: The reason for this is that we have perl modules that are interfacing with MySQL and we are retrieving the user id by reading $ENV{USER} (which in this case is "jwilkie"). It is a situation where we have one MySQL user defined but multiple people running the perl mod.
Does anyone have experience with this? Many many thanks! Jane
Normally, comments are stripped before the SQL statement is recorded in the binary log. However, a nasty workaround is to pretend that ypur comment contains syntax for some future version of MySQL - eg. 9.99.99:
/*!99999 user:jwilkie */ insert into tbl values (yyy);
These comments will then be passed through into the binary log.
If you have control over the SQL queries being generated, then you should be able to embed comments in them programatically in your query builder.
Select queries don't go in the binary log, but the comments may make it into the slow query log, general query log, etc.
Here's a blog post from Percona that touches on the subject a bit, specifically in the context of mk-query-digest. It might help:
http://www.mysqlperformanceblog.com/2010/07/05/mk-query-digest-query-comments-and-the-query-cache/
I am working with multiple databases in a PHP/MySQL application. I have development, testing, staging and production databases to keep in sync.
Currently we're still building the thing, so it's easy to keep them in sync. I use my dev db as the master and when I want to update the others I just nuke them and recreate them from mine. However, in future once there's real data I can't do this.
I would like to write SQL scripts as text files that I can version with the PHP changes that accompany them in svn, then apply the scripts to each db instance as I update them.
I would like to use transactions so that if there are any errors during the script, it will roll back any partial changes made. All tables are InnoDB
When I try to add a column that already exists, and add one new column like this:
SET FOREIGN_KEY_CHECKS = 0;
START TRANSACTION;
ALTER TABLE `projects` ADD COLUMN `foo1` varchar(255) NOT NULL after `address2`;
ALTER TABLE `projects` ADD COLUMN `foo2` varchar(255) NOT NULL after `address2`;
COMMIT;
SET FOREIGN_KEY_CHECKS = 1;
... it still commits the new column even though it failed to add the first one, of course, because I issued COMMIT instead of ROLLBACK.
I need it to issue the rollback command conditionally upon error. How can I do this in an adhoc SQL script?
I know of the 'declare exit handler' feature of stored procs but I don't want to store this; I just want to run it as an adhoc script.
Do I need to make it into a stored proc anyway in order to get conditional rollbacks, or is there another way to make the whole transaction atomic in a single adhoc SQL script?
Any links to examples welcome - I've googled but am only finding stored proc examples so far
Many thanks
Ian
EDIT - This is never going to work; ALTER TABLE causes an implicit commit when encountered: http://dev.mysql.com/doc/refman/5.0/en/implicit-commit.html Thanks to Brian for the reminder
I learned the other day that data definition language statements are always acted on in MySQL and cause transactions to be committed when they are applied. I think you'll probably have to do this interactively if you want to be sure of success.
I can't find the question on this website where this was discussed (it was only a couple of days ago).
If you need to keep multiple databases in synch, you could look into replication. Although replication isn't to be trifled with, it may be what you need. See http://dev.mysql.com/doc/refman/5.0/en/replication-features.html