I want to check if some values are set to Non-Null when opening a record. Dependent on that, I will show a message box to the user.
Currently I use:
Dim blnValueExists As Boolean
If DCount("*", "dbo_tbl_Parts", "Part_Nr = '" & Me!txt_PartNr & "' AND [ValuesExist] is Null") Then
blnValueExists = False
Else
blnValueExists = True
End If
But this will do the operation on client side. How could I achieve the same by shifting the request to the server?
I have used DoCmd.RunSQL at other parts, but I do not know how to get a easy "true/false" result from SQL Server back without needing to use recordsets etc.
Using dcount() in this way, or even spending all the time and money to build server side SQL stored procedure?
ZERO difference in speed. While the dcount() function is a client side function, it creates the correct sql, sends to server, gets the value back.
As a result, there is no need to consider, build, or attempt to create any kind of say pass-though query to sql server.
Even if you migrate say a large table - 2 million rows.
Now, bind a form to that linked table.
Now, do this:
docmd.OpenForm "frmInvoices",,"InvoiceNumber = 121325"
Access will ONLY pull the one rocord down the network pipe, and dispite the form being bound directly to the table of 2 million rows?
Not all rows are pulled to the client side.
So, with your dcount(), there is no need to attempt some kind of server side SQL or even having to adopt some kind of stored procedure on the SQL server side.
Your current code is fine, and adopting a recordset to replace dcount() DOES NOT and WILL NOT run faster.
Try:
If CurrentDb.OpenRecordset("Select Top 1 Part_Nr From dbo_tbl_Parts Where Part_Nr = '" & Me!txt_PartNr.Value & "' And [ValuesExist] Is Null").RecordCount Then
Related
I've got a query that joins 4 tables that I need to run against 4 different Access .mdb files (all have the same schema) so I can compare the results in Excel. Instead of creating 16 Power Queries and joining them into 4 queries (20 total query objects) I want to write a SQL statement that joins the tables and run it against each of the 4 different data sources. There's a chance that the SQL statement may need to be updated, so having it stored in one place will make future maintenance easier.
I could not find examples of this online and the way that Power Query writes M for an Access connection is based on one table at a time. I did not want a solution that used VBA.
Poking around with the various Power Query connectors I found that I can use the ODBC connector to connect to an Access database. I was able to adjust the parameters and pass it a standard SQL statement.
I put the SQL statement in a cell (C16 in the image) and named that range Package_SQL. I also have 4 cells where I put the path and filename of the 4 Access .mdb files I want to query. I name those ranges Database1 through Database4.
This is the configuration screen to set the database paths and set the SQL statement
let
// Get the Access database to work with.
dbPath = Excel.CurrentWorkbook(){[Name="Database1"]}[Content]{0}[Column1],
// Get the SQL statement from the named range
SQL = Excel.CurrentWorkbook(){[Name="Package_SQL"]}[Content]{0}[Column1],
Source = Odbc.Query("dbq=" & dbPath & "; defaultdir=C:\Temp;driverid=25;
fil=MS Access;maxbuffersize=2048;pagetimeout=5;dsn=MS Access Database", SQL),
#"Changed Type" = Table.TransformColumnTypes(Source,
{{"Issue_Date", type date}, {"Revision_Issue_Date", type date}})
in
#"Changed Type"
As you can see the magic is done in the following line. I didn't want the defaultdir to be hard coded to a folder that everyone may not have so I set it to C:\Temp. You may need to change it or even remove it and see if it makes a difference.
Source = Odbc.Query("dbq=" & dbPath & "; defaultdir=C:\Temp; driverid=25;
fil=MS Access;maxbuffersize=2048; pagetimeout=5; dsn=MS Access Database", SQL),
I made 4 instances of that query and created another query to combine the results. The query runs as fast as most any other Access query. I am very satisfied with this solution. The query can be altered and/or repurposed from the Excel sheet without digging through the Power Query scripts.
Note that this solution does not use any VBA.
I am trying to write a VBA code in Microsoft Access that will create and run 60 queries to select new records from 60 linked tables and insert them into 60 tables of the same format. Some background may help here:
I have a large database (lets call the original database "A") that will eventually have over 60 tables, 60 forms & 60 reports. When one of our workers goes out into the field and doesn't have an internet connection, they are going to create new records on a copy of the database stored on their desktop (lets call the duplicate database "B"). Once they have an internet connection, I want them to be able to press a button on either database (I have been trying to code the macro on database A because I thought that would be easiest) and have the new records they created on database B inserted into database A.
I have found code online that seems to be just what I need but when I try to run the macro it gives Error 3022, which says:
The changes you requested to the table were not successful because they would create duplicate values in the index, primary key, or relationship
I have tried running this macro with both databases on my desktop with only 1 linked table with a primary key that is an autonumber, I tried running it with a random autonumber, I tried not having any primary key or index or autonumber and even no records at all. I even tried running it without any linked tables. All ways of trying give me the same Error 3022. I really don't want to create 60 queries one by one so any help would be greatly appreciated. Thank you wizards in advance :)
Here is the code I have tried:
Public Sub ImportTableData(ByVal pstrTable As String, ByVal pstrDb As String)
Dim strSql As String
strSql = "INSERT INTO " & pstrTable & vbNewLine & _
"SELECT *" & vbNewLine & _
"FROM " & pstrTable & " IN '" & pstrDb & "';"
CurrentDb.Execute strSql, dbFailOnError
End Sub
Public Sub ImportAllTables()
Const cstrDb As String = "C:\MyPath\DatabaseB.accdb"
Dim tdf As TableDef
Dim strMsg As String
On Error GoTo ErrorHandler
For Each tdf In CurrentDb.TableDefs
'ignore system and temporary tables '
If Not (tdf.Name Like "MSys*" Or tdf.Name Like "~*") Then
Call ImportTableData(tdf.Name, cstrDb)
End If
Next tdf
ExitHere:
On Error GoTo 0
Set tdf = Nothing
Exit Sub
ErrorHandler:
Select Case Err.Number
Case 3078
strMsg = "Input table " & tdf.Name & " not found."
MsgBox strMsg
Resume Next
Case Else
strMsg = "Error " & Err.Number & " (" & Err.Description & ") in procedure ImportAllTables"
MsgBox strMsg
GoTo ExitHere
End Select
End Sub
When I remove the piece of code: 'dbFailOnError', I get different errors. First thing that pops up when I run the macro is: ''Input table 'LocalTableName' not found'', which is the table I am trying to add the records to. Once I click 'Ok' on that pop up box, that is when Error 3134 pops up which says 'Syntax error in INSERT INTO statement'. I am assuming Error 3134 only pops up because it cannot find the local input table (the fist pop up box).
Also, I tried changing the line of code that says: 'Const cstrDb As String = ''C:\MyPath\DatabaseB.accdb''' to instead point to database A (which is the one I am coding the macro on) like this: 'Const cstrDb As String = ''C:\MyPath\DatabaseA.accdb'''. This doesn't give me the first pop up that says ''Input table 'LocalTableName' not found'' but it still gives Error 3134.
I have no idea what I am doing wrong and have spent over 20 hours on this problem trying dozens of different things. Any help would be greatly appreciated :)
Well, the main issue is how you going to ensure that the PK (primary keys) and FK (foreign keys) remain the same when they go out to the field and start entering data?
There is a good chance that PK/FK values will now be duplicated, or be the same for on one of the field users.
If a user out in the field adds a record, and someone at main work location adds record, they now are to very likly have the same PK value.
I suppose this might work if you use random autonumbers (never even knew that was a option after all these years!!!) - but I can't say even that going to be 100% reliable.
And when you import that copy from the out in the field user, then either:
You always ensure you accept and take the same PK value, or you let access generate a new PK - but if you do that, then the child records FK value would have to be updated then.
You not really try to do a simple import, but are attempting to do a database synchronization- a stunning and VERY advanced concept. And a very challenging problem.
Access (mdb format) did at one time support what is called database replication. This feature would be ideal for your setup.
However, but for newer accDB formats, it not supported anymore. (and quite sure by around access 2010, replication support was dropped anyway).
So, you could try random for the autonumber. I mean, you simple cannot have the PK's being duplicated on each computer - plain and simple.
The other possbile?
You add to each and every table that has a PK, and add a new column called PKF (f for in the field).
And for every table that has a FK, you add a new column called FKF (again, add F to this).
So, in the field, your PK/FK used is NOT the same as the main master database at work.
So, I wrote a Android sync routine based on above. The applcation was Access, but I moved the data to sql server (but same idea). I moved to sql server since my android phone could use its local database (sqlLite) and hit sql server. (but, it would be difficult to get android to hit some server and read + use a accDB file - but was easy to have Android phone hit the sql server database directly).
Gee, maybe they could use Android phones!!! but, this would assume you up to speed writing android software, 100% conformable with SQL server, and also access. I was lucky, had all 3 skill sets, so that is the road and hammer I choose.
And speaking of above?
Maybe your lucky, and you have sql server running at work (not express edition, but full edition). I suggest this considering, since the free edition of SQL express can be what we call a replication subscriber to a main sql database. This allows you to sync your local database with the main mothership database.
So, adopting free SQL server express on each field laptop could be a possible solution. Then when they get to a working network, they sync the database using replication.
But, you could try and roll your own sync system.
I did that for an android applcation I wrote, and for a desktop Access application I had. (but, to make all the moving parts easy, I did adopt sql server for database - continued to use Access as the application/UI part).
Now, using "random" for the PK looks to be a possible solution. I just don't know how random, and if this choice can reliable avoid PK collisions for autonumbers.
Random seems like the best road - but ONLY if that choice would prevent duplicate PK id's being used out in the field for new records.
Edit: Random - not even close - it not random enough
So, a bit of research - no, random PK will not work, you still often wind up with collisions - so that idea is off the table.
I figured it out finally. Basically I changed the line of code that executes the SQL to debug.print. This showed me what was going on. The problem is I had linked the tables from the other database when they didn't need to be linked. The names of the local tables would be 'Table A' & the linked tables were 'Table A1'. So there would be a query generated for 'Table A' and another query generated for 'Table A1'. Since there are no tables by the name 'Table A1' in Database B, the query wouldn't work. Plus the fact that, in the line of code executing the SQL, there was an option that says 'dbFailOnError' so since half of the queries weren't working, this option rolls back any updates made by the queries that did work.
I removed all of the linked tables and the macro runs perfectly, unless there are records that are the same on both databases. If I remove 'dbFailOnError' from the code, then the macro runs well no matter what.
So the macro is doing what I want it to but I would like to keep the 'dbFailOnError' part of the code so I will have to do 2 things. First, I have to solve the problem with the primary keys. The answer on this thread by Albert describes this problem well. Second, I have to adjust the SQL to be able to only select records that don't already exist in Database A. I am assuming I can do this by adding a WHERE to the end of the SQL.
I will make an update once I fix these problems, or if I just run an SQL server instead.
Thank you everyone for your help :)
I am trying to figure out how to download using an ADO/DAO connection in Access VBA to get the contents of a table from SQL server. I am trying to avoid using a linked table because the DB requires a password and I keep running into issues with getting it to not ask for the login info. Are there any ideas or references for me to start with on this matter?
It appears either way you'll need to provide SQL credentials.
There's more involved without linking a table, basically you'd want a recordset for the source and the "target" table to iterate over.
targetrs = CurrentDb.OpenRecordset("Target", dbOpenTable)
Dim Con As New ADODB.Connection
Dim sqlStr As String
Con.Open _
"Provider = sqloledb;" & _
"Data Source=SqlServer;" & _
"Initial Catalog=MyDB;" & _
"User ID=sa;" & _
"Password=p#ssW0rd;"
Dim rsSource As New ADODB.Recordset
rsSource.Open "select * from SOURCE", Con
do until rsSource.eof
targetrs.addnew
for each field in rsSource
targetrs.fields(field.Name) = rsSource.fields(field.Name)
next
targetrs.update
rssource.movenext
loop
Since you still have to have the credentials, you could dynamically link the table instead:
docmd.TransferDatabase acLink,"ODBC Database",
"ODBC;Driver={SQL Server};Server=MySQLServer;Database=MYSQLDB;
Uid=USER;Pwd=PASSWORD",acTable,"SQLtable","MyAccessTable"
Use of a linked table does not require you store or have the user password in that linked table.
If you execute a SINGLE logon at application startup then all linked tables will work.
Linked tables work WITHOUT a prompt for user or password.
Linked tables work WITHOUT you having to store the user ID or password in the link.
Access will cache the user name + password if you logon as per the instructions here:
http://blogs.office.com/b/microsoft-access/archive/2011/04/08/power-tip-improve-the-security-of-database-connections.aspx
So to download a table to a local, then you ONLY need this code:
For a new local table (create table query):
CurrentDb.Execute "SELECT * INTO LocalTableCreate FROM ServerTable"
Append to existing table:
CurrentDb.Execute "INSERT INTO LocalTable SELECT * FROM ServerTable"
And if some really strange reason and desire exists create and promote world poverty and do things the hard way like a turtle with time to waste and not use a linked table?
Well you could create a linked table via the “transfer database” command. It is only one extra line of code in front of the above code and then AGAIN the above two examples would work fine.
However I see little if any advantage to creating + deleting a linked table.
I suppose for reasons of performance or perhaps for security or the legitimate reason of you not knowing the table ahead of time? Then I would suggest you use a saved a pass-though query as performance will be even faster.
So you can use this code:
Dim qdfPass As DAO.QueryDef
Set qdfPass = CurrentDb.QueryDefs("MyPass")
qdfPass.SQL = "select * from dbo.MyTable;"
CurrentDb.Execute "INSERT INTO LocalTable SELECT * FROM MyPass”
Note that the sql used in above qerydef MUST be native T-SQL and can be a view or even a store procedure like:
qdfPass.SQL = "exec sp_myCoolStoreProc;"
And the stored procedure can even be passed a parameter like this:
qdfPass.SQL = "exec sp_myCoolStoreProc " & strMyParam
and then :
CurrentDb.Execute "INSERT INTO LocalTable SELECT * FROM MyPass”
So we can even use a select into/append from a store procedure by doing the above and the table/sql server side is dynamic or can even be a stored procedure. Again VERY little code.
I would suggest you avoid the idea proposed here to write recordset looping code unless one really has the desire to write looping code when none is required. And things like PK would have to be dealt with separate in code if you use such loops since the local pk column may need to be skipped (you simply leave that column out of the select SQL).
Note again that the connection string saved for the pass-though query does NOT require the user ID and password by using the above link showing how to “logon” to SQL Server. And if the table is known, then again a saved table link or pass-though query will suffice here.
My project is in Visual Foxpro and I use MS SQL server 2008. When I fire sql queries in batch, some of the queries don't execute. However, no error is thrown. I haven't used BEGIN TRAN and ROLLBACK yet. What should be done ??
that all depends... You don't have any sample of your queries posted to give us an indication of possible failure. However, one thing I've had good response with from VFP to SQL is to build into a string (I prefer using TEXT/ENDTEXT for readabilty), then send that entire value to SQL. If there are any "parameter" based values that are from VFP locally, you can use "?" to indicate it will come from a variable to SQL. Then you can batch all in a single vs multiple individual queries...
vfpField = 28
vfpString = 'Smith'
text to lcSqlCmd noshow
select
YT.blah,
YT.blah2
into
#tempSqlResult
from
yourTable YT
where
YT.SomeKey = ?vfpField
select
ost.Xblah,
t.blah,
t.blah2
from
OtherSQLTable ost
join #tempSqlResult t
on ost.Xblah = t.blahKey;
drop table #tempSqlResult;
endtext
nHandle = sqlconnect( "your connection string" )
nAns = sqlexec( nHandle, lcSqlCmd, "LocalVFPCursorName" )
No I don't have error trapping in here, just to show principle and readability. I know the sample query could have easily been done via a join, but if you are working with some pre-aggregations and want to put them into temp work areas like Localized VFP cursors from a query to be used as your next step, this would work via #tempSqlResult as "#" indicates temporary table on SQL for whatever the current connection handle is.
If you want to return MULTIPLE RESULT SETs from a single SQL call, you can do that too, just add another query that doesn't have an "into #tmpSQLblah" context. Then, all instances of those result cursors will be brought back down to VFP based on the "LocalVFPCursorName" prefix. If you are returning 3 result sets, then VFP will have 3 cursors open called
LocalVFPCursorName
LocalVFPCursorName1
LocalVFPCursorName2
and will be based on the sequence of the queries in the SqlExec() call. But if you can provide more on what you ARE trying to do and their samples, we can offer more specific help too.
I have a table (readings) already connected by ODBC in Access that opens very quickly when I click on it.
However, when I try to run this in VBA I it locks up and never displays anything:
Dim strSql As String
strSql = "SELECT readings.ids " & _
"INTO ids_temp " & _
"FROM readings " & _
"WHERE readings.ids > 1234;" //This is id in middle of list
DoCmd.SetWarnings False
DoCmd.RunSQL strSql
DoCmd.SetWarnings True
For some reason this crashes the whole system. Any ideas?
Rather than using DoCmd, t's usually handled by your existing connection to create a Command object, which accepts SQL statements to use with the Command.Execute method.
Reading the documentation for DoCmd, it appears to primarily be intended for eexecuting Macros from the Access UI menus.
Does you Database have ids_temp table locally? If ids_temp table is Linked table it will delete the table, because select into CREATES NEW TABLE. If you want to add to table try INSERT INTO command. You can clean table before inserting the data.
So the error was actually my fault the id I was using was causing the Query to return about 6 million results. But, this method actually works great, I just create the table and link a list box on a different form to the table, then I just show the form. I do some closes and updates in between but overall it seems to work well. Thanks for the help
Let me say that DoCmd.RunSQL is never advisable, particularly with SetWarnings turned OFF, as you have no idea whether the result is what you expect or not. You've told VBA not to report errors, so you never know if all the records were inserted or not.
It's very easy to replace DoCmd.RunSQL with my SQLRun() function, posted here:
How can I get a value from the update query prompt in Access VBA?