I have an application that uses myBatis.
I do not want to convert the resultset from mybatis to a Java object. So essentially I do not want a mapped object. I just want the resultset.
Is it possible to get that from myBatis?
Something like:
Resultset resultset = mybatisMapper.getResults();
I already have a program which processes this Resultset and I cannot change that program.
If you don't want a mapped object as result of your query you don't have to use a mapper. Try to take a look to this link, I think it can be useful for you:
Ibatis/MyBatis select dynamically without need to create any Pojo / Mapper
Related
What's the best approch to have a dynamic query like
select $dynamic_columns from table
But also prevent error like column not found and get result with available columns. considering $dynamic_columns is given by end users.
One approach would be to store the schema in java object and filter it. Again if schema is update in DB we will need to update the schema java object cache. is there any better way to handle this?
Be careful with this as it is more vulnerable to SQL injection.
Never let the user type something into a text field, instead build a
list for them to select from.
For building the list, I think the best approach is to use the JDBC method DatabaseMetaData.getColumns(...) to retrieve a list of columns for a table. I don't think there's a need to cache anything.
I have next issue:
I have list of names, based on which I want to filter.The problem is that I have not full names(Because I'm receiving them from ui), and I have, for example, this array= ['Joh', 'Michae'].
So, I want to filter based on this array.
I wrote query in PostgreSQL
select * from q_ob_person where name like any (array['%Хомяченко%', '%Вартопуз%']);
And I want to ask how to write JPQL query gor this.
Is there an option to call postgresql function like any from JPQL?
JPA 2.1 allows invocation of any SQL function using
FUNCTION(sqlFuncName, sqlArgs)
So you could likely do something like (note never tried this LIKE ANY you refer to, just play around with it)
FUNCTION("LIKE", FUNCTION("ANY", arrayField))
Obviously by invoking SQL functions specific to a particular RDBMS you lose database independence (in case that's of importance).
I am using slick with play2.
I have multiple fields in the database which are managed by the database. I don't want to create or update them, however I want to get them while reading the values.
For example, suppose I have
case class MappedDummyTable(id: Int, .. 20 other fields, modified_time: Optional[Timestamp])
which maps Dummy in the database. modified_time is managed by the database.
The problem is during insert or update, I create an instance of MappedDummyTable without the modified time attribute and pass it to slick for create/update like
TableQuery[MappedDummyTable].insert(instanceOfMappedDummyTable)
For this, Slick creates query as
Insert INTO MappedDummyTable(id,....,modified_time) Values(1,....,null)
and updates the modified_time as NULL, which I don't want. I want Slick to ignore the fields while updating and creating.
For updating, I can do
TableQuery[MappedDummyTable].map(fieldsToBeUpdated).update(values)
but this leads to 20 odd fields in the map method which looks ugly.
Is there any better way?
Update:
The best solution that I found was using multiple projection. I created one projection to get the values and another to update and insert the data
maybe you need to write some triggers in table if you don't want to write code like row => (row.id,...other 20 fields)
or try use None instead of null?
I believe that the solution with mapping non-default field is the only way to do it with Slick. To make it less ugly you can define function ignoreDefaults on MappedDummyTable that will return only non default value and function in companion object to MappedDummyTable case class that returns projection
TableQuery[MappedDummyTable].map(MappedDummyTable.ignoreDefaults).insert(instanceOfMappedDummyTable.ignoreDefaults)
How does Slick handle a query that returns multiple result sets?
For example, if I wanted to retrieve information about a table using sp_help someTableName
Which would return a number of result sets. I can get the first result set, simply using scala.slick.jdbc.StaticQuery.queryNA[Tuple4[String, String, String,String]]("sp_help tblInbox_membership").first()
How do I get the second result set?
You must be using Sybase or maybe SqlServer.
I'm not familiar with Slick (yet), but the way to access subsequent ResultSets from a statement in JDBC is to call Statement.getMoreResults(), then if that succeeds Statement.getResultSet(). Slick gives you a Statement object with Session.withStatement, so you could at least use the JDBC api to get your resultsets, or feed the ResultSet to Slick if there is a way to do that.
I have no idea why any one would do this (include support for Lists in named queries but not native named queries (and believe me when I tell you I am steaming mad about this). How can one get around this flaw? I can't possibly put all the place values for the array into the native query, It could be up to several hundred units long!!!!! How would you handle this?
Can you pass a List as a parameter to a normal SQL statement? No.
/**
* Create an instance of Query for executing a native SQL statement, e.g., for update or delete.
* #param sqlString a native SQL query string
* #return the new query instance
*/
public Query createNativeQuery(String sqlString);
When you create a native query, the JPA provider will blindly pass that SQL to the database and it assumes the user has formatted the SQL appropriately.
If you want to pass a List as a query parameter, use JPQL.