Someone asked a similar question here: 1
This code works:
IDatabaseConnection connection = getConnection();
ITableFilter filter = new DatabaseSequenceFilter(connection);
IDataSet dataset = new FilteredDataSet(filter, connection.createDataSet());
FlatXmlDataSet.write(dataset, new FileOutputStream(file));
It dumps the entire database to an XML flat file. Good. We know my username/password/drivername/connection string etc.. are good.
Now how do I modify it so I can supply a SQL select statement and export the results of a single query?
I did some google searching and found this code:
System.out.println("begin partial");
IDatabaseConnection connection = getConnection();
QueryDataSet partialDataSet = new QueryDataSet(connection);
partialDataSet.addTable("gov", "SELECT * FROM GOV_UNIT");
partialDataSet.addTable("gov_unit");
FlatXmlDataSet.write(partialDataSet, new FileOutputStream("partial-dataset.xml"));
System.out.println("end partial");
This does not create the file "partial-dataset.xml" like I hoped. It just prints "begin partial" and "end partial".
Can someone help me make this code work? What am I doing wrong? Of course, when get this to work, I'll replace the simple query with a recursive join that works with my postgresql database.
Thanks
siegfried
Your code is OK. This line FlatXmlDataSet.write(partialDataSet, new FileOutputStream("partial-dataset.xml"));, does not create XML file, you have to create it manually before . This is all you need.
Related
I can't find any documentation on how to manager parameters into Database Reader SQL statements?
-> this is a simplified example: I am not looking for scripting a variable to "yesterday" which is easy to express in SQL. That's not the point. I have have more complex variables in the actual SQL statement I'm trying to martial in. I just want to know how to get variables into the SQL form if possible.
-> "you can just do that in JavaScript": the actual queries I need to run are about a hundred lines long, I don't want to maintain and debug a query build by concatenating strings and then deal with escaping 'quoted' things everywhere in the SQL. I really prefer to maintain an actual SQL statement that copy/paste works in a SQL IDE.
How do we pass in parameters into the SQL block at the bottom of the Database Reader form?
SELECT patientsex, visitnumber, samplereceived_dt, sr_d, sr_t, orderpriority, orderrequestcode, orderrequestname
FROM mydata.somedata
WHERE sr_d = (${DateUtil.getCurrentDate('yyyyMMdd')})::integer;
JavaScript is the feasible way to achieve this, with SQL statements defined inside Mirth connect or have the SQL statements bundled in a stored procedure then use SQL server's Exec command within Mirth connect to call the stored procedure while passing the parameters (interestingly using JavaScript).
For example
var dbConn;
try {
dbConn = DatabaseConnectionFactory.createDatabaseConnection('','DB:Port\instance','user','pass');
var paramList = new java.util.ArrayList();
paramList.add($('patientId'));
paramList.add($('lastName'));
paramList.add($('firstName'));
var result = dbConn.executeCachedQuery("SELECT * FROM patients WHERE patientid = ? AND lastname = ? AND firstname = ?) ",paramList);
while (result.next()) {
//you can reference by column index like so...
//result.getString(1);
}
} finally {
if (dbConn) {
dbConn.close();
}
}
Should be noted that the parameters you add to the list MUST be in order.
I would like to know if there is a way to set db using a variable
For example: I am coding in Python, and I connect using client = MongoClient(uri). All goes fine.
There are 4 dbs: test1,test2,test3,test4.
I am able to list them all.
dblist = client.list_database_names()
print(dblist)
All goes fine.
Now, Instead of connecting/ using
db = client.test1
Is there a way to use a string rather than actual name of the db?
such as str = 'test1', and then db=client.str.
(this doesn't work)
In my program , I display the list of dbs first and then I am taking user input on the db , and proceed with further flow, but unable to do so.
Please help.
You cannot add string as an name when it comes to that. However there is another function that takes string of the name of certain database and gets the database.
db=client.get_database('test')
Here is the documentation: https://api.mongodb.com/python/current/api/pymongo/mongo_client.html
I have a query that is working in all my other php files but it will not work here. Can someone please look at what I have and let me know why the query is not selecting the fields?
Please keep in mind that $res is my database connection that's open, and all the table fields are spelled correctly to the table. I have tried not having those single quotes that are sideways and as you can see in the code I have tried it with them. I have also tried not having ' ' and have tried it with them. I can remark out the lines and the code works, but put them back live and the code stops working with no error given.
I don't know if this helps, but my PHP version is 5.3.3-40.el6_6
$result2 = mysqli_query($res, "SELECT pre_sponsor_sponsor, slid FROM `pres` WHERE `pre_sponsor` = '$spospo' AND `slid` = '$slid' AND `pre_id` <= '$pre_id' LIMIT 1");
$row2 = mysqli_fetch_array($result2)
$spospo = $row2[pre_sponsor_sponsor];
$slid = $row2[slid];
First of all you missed semicolon at line 3.
But I think you should write
$row2 = mysqli_fetch_array($result2, MYSQLI_ASSOC);
Regards.
I see my problem after posting it here. I forgot the semi-colon after the $row2 = mysqli_fetch_array($result2) - it should have a ; after it.
Sorry for posting this.
Correct me if I am wrong about EntityFramewroks.
As far as I understand, it is impossible to execute a query against the database when you do not know what results (objects) you are going to get in return because it needs to map the results to the expected object, which is passed when executing raw SQL query against the database.
Question: How can one execute SQL query without specifying the object?
Your help (and any input) will be highly appreciated.
Kind regards,
Moses
It is still unclear what you are asking, but I will adapt answer to your edits of your question.
I think you are referring to something like: http://msdn.microsoft.com/en-gb/data/jj592907.aspx
using (var context = new BloggingContext())
{
var blogs = context.Blogs.SqlQuery("SELECT * FROM dbo.Blogs").ToList();
}
or
using (var context = new BloggingContext())
{
var blogNames = context.Database.SqlQuery<string>(
"SELECT Name FROM dbo.Blogs").ToList();
}
I am using code similar to this Support / KB article to return multiple recordsets to my C# program.
But I don't want C# code to be dependant on the physical sequence of the recordsets returned, in order to do it's job.
So my question is, "Is there a way to determine which set of records from a multiplerecordset resultset am I currently processing?"
I know I could probably decipher this indirectly by looking for a unique column name or something per resultset, but I think/hope there is a better way.
P.S. I am using Visual Studio 2008 Pro & SQL Server 2008 Express Edition.
No, because the SqlDataReader is forward only. As far as I know, the best you can do is open the reader with KeyInfo and inspect the schema data table created with the reader's GetSchemaTable method (or just inspect the fields, which is easier, but less reliable).
I spent a couple of days on this. I ended up just living with the physical order dependency. I heavily commented both the code method and the stored procedure with !!!IMPORTANT!!!, and included an #If...#End If to output the result sets when needed to validate the stored procedure output.
The following code snippet may help you.
Helpful Code
Dim fContainsNextResult As Boolean
Dim oReader As DbDataReader = Nothing
oReader = Me.SelectCommand.ExecuteReader(CommandBehavior.CloseConnection Or CommandBehavior.KeyInfo)
#If DEBUG_ignore Then
'load method of data table internally advances to the next result set
'therefore, must check to see if reader is closed instead of calling next result
Do
Dim oTable As New DataTable("Table")
oTable.Load(oReader)
oTable.WriteXml("C:\" + Environment.TickCount.ToString + ".xml")
oTable.Dispose()
Loop While oReader.IsClosed = False
'must re-open the connection
Me.SelectCommand.Connection.Open()
'reload data reader
oReader = Me.SelectCommand.ExecuteReader(CommandBehavior.CloseConnection Or CommandBehavior.KeyInfo)
#End If
Do
Dim oSchemaTable As DataTable = oReader.GetSchemaTable
'!!!IMPORTANT!!! PopulateTable expects the result sets in a specific order
' Therefore, if you suddenly start getting exceptions that only a novice would make
' the stored procedure has been changed!
PopulateTable(oReader, oDatabaseTable, _includeHiddenFields)
fContainsNextResult = oReader.NextResult
Loop While fContainsNextResult
Because you're explicitly stating in which order to execute the SQL statements the results will appear in that same order. In any case if you want to programmatically determine which recordset you're processing you still have to identify some columns in the result.