So I basicly have a table which has a list of table names. All these listed tables have exact same structure.
Then I have a query template, with place holder for table name.
I need to create a view, which should return results of that query UNIONed from all the tables listed in that one setup table.
So far what I've done is create a user defined function, which would prepare a complete UNIONed SQL statement.
But this is where I'm stuck. I can't figure out how to execute it in a view and return whatever it returns..
My function returns SQL syntax.
I figured that UDF can't executed dynamic sql, so my method won't work. So far I've solved my issue at hand by generating views. But I would still prefer a more dynamic way..
Related
I’m experiancing a problem when trying to link to tables in the database expert. The two fields that link the tables have exactly the same information except one table always has an additional space. For example;
Table 1 = Multivitamin/Tablets
Table 2 = Multivitamin//Tablets
‘/‘ are representing spaces
Formulas won’t help (e.g. extractstring etc) as it’s the tables themselves I need to link together
This is preventing me from retrieving the information I need. Any advice on how I can get around this?
There are some ways to come across this:
Consider using a command as datasource instead of tables. When writing the query of the command you can define the join condition yourself.
If you have access to the data source, you could add a calculated field to the tables to contain the normalized field values and then use these for linking in CR.
Alternatively, one could create views in the database, either adding normalized "linking fields" or providing the joined tables results.
If it's only a few rows in CR, you could consider using SQL fields or subreports to retrieve data from Table 2.
I need to update a mapping table in postgresql, but of course it won't allow me to replace/drop the original table as there are dependencies.
The error message details does list the dependent views, but I'd like to generate a list programmatically so that I can make temp views while I drop my original mapping table and migrate the views back afterwards.
Prefer not to do this in SQL Shell incidentally. Any pointers would be much appreciated.
I'm loading a subset of the parent records and the child records into a dataset then setting datarelations and foreignkeyconstraints, so when I am building the dataadapter select stmt for the child records, I must make sure that only the child records whose parent is present is loaded to avoid referential integrity errors. Since the subset of the ParentTable has been loaded into a dataset I tried:
daChild = new OleDBDataAdapter(CreateOledbCommand("select * from Childtable where ChildKey in (ds.tables(""ParentTable""))",dconn))
But got an "undefined function 'ds.tables' in expression" error at runtime.
So, I tried to create a one column table to pass to the IN clause, like this:
Dim MyDataView as DataView = New DataView(ds.tables("ParentTable"))
Dim MyTempParentTable as DataTable = MyDataView.ToTable(False, "ParentKey")
daChild = New OleDbDataAdapter(CreateOledbCommand("select * from ChildTable where ChildKey in (MyTempParentTable)", dconn))
I checked in the debugger, and MyTempParentTable is, in fact, a one column table containing the key of the ParentTable. I thought that the IN clause could take a one column datatable as valid input. Apparently not, as I am getting a "No value given for one or more required parameters" error at runtime.
I'm just about out of ideas. All my google searching came up with for the IN clause was something like IN (value1, value2, value3...) and doesn't give any examples for the IN clause containing a more complex expression.
Can anyone clue me in on what I'm missing, or maybe a different way to accomplish this? I'm trying to get the IN clause to work because I'm thinking that it is the most efficient way to do this... Maybe it's not... Thanks for any help.
I haven't found an answer to the question about why the IN clause didn't work, but just in case anybody else has this issue I will post my workaround.
I load the parent records as usual, but my dataadapter select stmt for the child records has a "WHERE 1=0" so that zero records are initially loaded. When a new parent record is displayed I then determine if the child records for that parent are already loaded into the dataset, if not, I load them in. Bottom line is that I don't pre-load the child records, rather, I load them "on demand". This solution is working well for me.
how would I ignore having Zend_DB save() from trying to fill out a created column? I do not need that column for a certain model.
Don't send the data. save() is part of the Zend_Db_Table_Row api and is designed to be somewhat intelligent in the way it saves data to a row. It will perform an insert or an update of a row depending on what is required.
save() will also only update the columns that it has data for. If you don't send new data for your created column save() won't overwrite the data.
When ever it is possible I let the database I'm using create and update the columns for created and updated. That way I have the information available to query if I need it but I don't have to do something with PHP that My database can do better.
Check out http://framework.zend.com/manual/1.12/en/zend.db.table.html Section "Advanced usage".
For more specific and optimized requests, you may wish to limit the
number of columns returned in a row or rowset. This can be achieved by
passing a FROM clause to the select object. The first argument in the
FROM clause is identical to that of a Zend_Db_Select object with the
addition of being able to pass an instance of Zend_Db_Table_Abstract
and have it automatically determine the table name.
Important
The rowset contains rows that are still 'valid' - they simply contain
a subset of the columns of a table. If a save() method is called on a
partial row then only the fields available will be modified.
So, if you called an update() I think it would be as simple as unsetting the value for the column you don't want to touch. Of course database constraints will need to be honored - i.e. column should allow nulls.
Can any one help me why this error occurs when i update using sqlDataadapter with join query
Dynamic SQL generation is not supported against multiple base tables.
You have a "join" in your main query for your dataset (The first one in the TableAdapter with a check by it). You can't automatically generate insert/update/delete logic for a TableAdapter when the main query has multiple tables referenced in the query via a join. The designer isn't smart enough to figure out which table you want to send updates to in that case, that is why you get the error message.
Solution. Ensure that your main query only references the table you want the designer to write insert/update/delete code for. Your secondary queries may reference as many tables as you want.
It was in the case that i was trying to set value for identity column in my datarow. Simply i deleted the code to set value for identity column and it will work.
My Scenario:
Database:
uin [primary, identity]
name
address
Whenever i tried to set the datarow("uin") the error occurs. But works fine with datarow("name") and datarow("address").
Hope it works for you too