I have a sequence in my database, which I generated through Liquibase. During refactoring, we decided that we didn't like the name that we gave it, and we would like to rename it, preserving all data that currently exists for it.
It seems possible to alter a sequence, but I'm not seeing anything about how to rename the sequence. Is there a way to do it, or a reasonable workaround?
(If it matters, I'm using Oracle SQL)
Although not documented, this refactoring is supported by Liquibase. Not sure what version this change was implemented in, but the class supporting the feature was commited on 30 Jan 2014. What's interesting though, is that the original issue is still unresolved.
Anyway, the refactoring is supposed to be working only on Oracle and Postgres. I've tested it on Oracle with Liquibase 3.4.1:
databaseChangeLog:
- changeSet:
id: change_set_id
author: me
dbms: oracle
changes:
- renameSequence:
oldSequenceName: old_name_seq
newSequenceName: new_name_seq
The above refactoring is in YAML format, but you could easily guess its XML counterpart.
On Oracle, this generates the following statement:
RENAME old_name_seq TO new_name_seq;
2 other supported parameters are catalogName and schemaName.
There is not currently a built-in refactoring to rename a sequence. If your database engine supports it, you could execute whatever methods are supported using a <sql> or <sqlFile> change.
You said you were using Oracle SQL. The RENAME statement allows for renaming a sequence. So your Liquibase script would look like this:
<sql>RENAME old_sequence_name TO new_sequence_name</sql>
Related
I'm working on updating hundreds of calculation views on SAP HANA.
I should update (for every calculation view) the last aggregation/projection columns : Keep flag = True.
There's a way, by updating XML Code of every calculation view file Like below:
<attribute id="EQUNR" order="3" attributeHierarchyActive="false"
displayAttribute="false" keepFlag="true">
<descriptions defaultDescription="EQUNR"/>
But, my question is, is there a way to update this Keep Flag through a query on SQL Console ?
if not, is there any other method you suggest guys ?
Every idea matters, Thank you folks
There is no way to achieve this via SQL.
Although you may be able to author a regex expression that matches some of the target XML tags, there’s no way of correctly updating the repository tables storing the source XML (if you’re using the HANA classic repository).
For HANA 2 HDI files no DB command can change the source code as these are not stored in the database.
Beyond this technical issue, it’s probably not a good idea to apply a flag that changes query semantics as a batch update.
I use liquibase diff generate the diff between dev mysql and prod mysql, I see there exist some change set like:
When I run the diff file, it shows exception like:
setColumnRemarks is not supported on mysql, db/changelog/V1.1.0_prod_uat.xml::1524893614482-984::davy (generated)
setColumnRemarks is not supported on mysql, db/changelog/V1.1.0_prod_uat.xml::1524893614482-985::davy (generated)
setColumnRemarks is not supported on mysql, db/changelog/V1.1.0_prod_uat.xml::1524893614482-986::davy (generated)
at liquibase.changelog.DatabaseChangeLog.validate(DatabaseChangeLog.java:276)
at liquibase.Liquibase.update(Liquibase.java:198)
at liquibase.Liquibase.update(Liquibase.java:179)
at liquibase.integration.spring.SpringLiquibase.performUpdate(SpringLiquibase.java:317)
at liquibase.integration.spring.SpringLiquibase.afterPropertiesSet(SpringLiquibase.java:269)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1769)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1706)
How to resolve this problem?
Object's comment update (Liquibase's set*Remarks) is not supported for some databases, including MySQL. So immediate fix could be to remove this action from your change log.
In my project we generating change sets by comparing (with liquibase diffChangeLog) 2 schemas, and setColumnRemarks actions are included although they cannot be executed afterwards. So I'm just removing these actions from resulting change sets.
I am afraid a proper solution would be to add appropriate MySQL SQL generator implementation to Liquibase.
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 am attempting to generate a change log against a MariaDB server. I am able to successfully generate a change log, however if I do a dropAll and update to validate that it is useful, there are multiple problems with it. I have tried using both the native mariadb and MySQL jdbc connectors and both experience these problems. I am also using liquibase 3.1.1.
The first is that there are deferrable and initiallyDeferred flags which are not supported by MySQL. The update command specifically calls these out as being invalid flags against MySQL.
Once I remove all of those references in the .xml, attempting to update runs into a sql syntax error because a double datatype is defined as DOUBLE(22) (in the xml). This is not a valid syntax for a double in mariadb or MySQL. They accept no parameters, or DOUBLE(m,d); my database is defined as default (no parameters).
Now its trying to create a table with an auto_increment but not specifying that the column is also a key in the create table statement; ie. it's missing the primaryKey constraint.
And I'm sure there are more problems in line as I work my way through the changelog (this is just changeset 116 out of 1500+).
Its almost as if liquibase is creating the changelog based on it thinking the db is a different type (postgres/oracle?).
Am I missing something?
You are right, the problem is that Liquibase is thinking it is an unknown database and doesn't know it is almost mysql. There is an issue open to add mariaDB support (https://liquibase.jira.com/browse/CORE-1411) but it hasn't been implemented quite yet.
The easiest work-around would be to add an extension:
Create a new liquibase.database.ext.MariaDBDatabase class in your codebase that extends liquibase.database.core.MySQLDatabase and override the isCorrectDatabaseImplementation(DatabaseConnection conn) method that returns true if conn.getDatabaseProductName() equals whatever the MariaDB jdbc driver is returning.
You may also want to override the getDefaultDatabaseProductName() to return "mariadb" instead of MySQL so you can differentiate it with contexts
I had understood that jOOQ would simulate SQL MERGE on systems (such as PostgreSQL) that don't support it.
I have a table with a serial (autoincrement) "id" column and a string "uri" column. I want to use numeric IDs instead of URIs in my database, so I have to make sure I have a URI in the ID lookup table. So following the example in the jOOQ manual, I thought this would work:
createDSLContext().mergeInto(tableByName("uris"))
.using(createDSLContext().selectOne())
.on(fieldByName("uri").equal("http://example.com/"))
.whenNotMatchedThenInsert(fieldByName("uri"))
.values("http://example.com/").execute();
This gives me a DataAccessException saying something like:
SQL [merge into "uris" using (select 1) on "uri" = ? when not matched then insert ("uri") values (?)]; ERROR: syntax error at or near "merge"
But then the log says jOOQ goes ahead and tries to execute the query with bind values. But the table is never updated. So I'm guessing the jOOQ doesn't simulate MERGE on PostgreSQL?
So I then try the H2 database syntax:
createDSLContext().mergeInto(tableByName("uris"), fieldByName("uri")).values(uri.toString()).execute();
I get:
The H2-specific MERGE syntax is not supported in dialect : POSTGRES
What!? But the jOOQ documentation says that the H2 syntax "can be fully simulated by jOOQ for all other databases that support the SQL standard." Surely PostgreSQL supports the SQL standard. Does it really mean "...the SQL standard version of MERGE?"
Is there any way to get PostgreSQL support for MERGE via jOOQ, or am I stuck doing the same workarounds I would do anyway?
To be sure if a given SQL feature is supported by jOOQ for your database, please consider the Javadoc's #Support annotation on the relevant DSL method. This is also documented in the manual. In this case, DSLContext.mergeInto(), where you can see that this statement is currently only supported for these SQLDialects:
#Support(value={CUBRID,DB2,HSQLDB,ORACLE,SQLSERVER,SYBASE})
MERGE is a very powerful statement that is not really easy to emulate if your database doesn't natively support it.
"can be fully simulated by jOOQ for all other databases that support the SQL standard." Surely PostgreSQL supports the SQL standard. Does it really mean "...the SQL standard version of MERGE?"
Yes of course, the SQL standard MERGE statement must be supported :-) We'll clarify this in the manual. I have registered issue #3183 for this.
Is there any way to get PostgreSQL support for MERGE via jOOQ, or am I stuck doing the same workarounds I would do anyway?
Right now, unfortunately, we don't have a solution for this in PostgreSQL. Feel free to discuss possible solutions on the jOOQ User Group.
Yes , it can support which database support the merge in SQL stand.
but postgresql unsupport this feature in SQL standard.
Please see
F312 MERGE statement
F313 Enhanced MERGE statement
F314 MERGE statement with DELETE branch
http://www.postgresql.org/docs/9.3/static/unsupported-features-sql-standard.html