I have a datatable, containing two rows: id char(9), eh char(4). Both rows contains numeric values (I can't change this), for example 123456789.
The query
SELECT id,eh FROM tab WHERE id LIKE '123456789'
directly in the MySQL-client works fine, in VB.net too.
But if I use a parameter in VB.net instead of building the query-string, the query returns null rows. This is what I've done (not the complete code):
Dim com As New MySqlCommand
com.CommandText = "SELECT id,eh FROM tab WHERE id LIKE #i"
com.Parameters.Add("#i", MySqlDbType.VarChar)
com.Parameters("#i").Value = number
I think, the connector does not send the quotes of the string (maybe because there are only numbers), because if I change the first query in the MySQL-client to ... LIKE 123456789, I get null rows, too.
Do you have any hints or workarounds for me?
Try
MySqlDbType.String
As your parameter type.
Note.. I do not use MySql but a quick google came up with char as a string.
EDIT
Maybe you are missing the Apostrophes around you #i
com.CommandText = "SELECT id,eh FROM tab WHERE id LIKE '#i'"
Related
Any help that can be provided to a Access and VB noob would be greatly appreciated. What I'm trying to do is concatenate the values from one table and insert it as a comma delimited value into a field in another table. I'm trying to take all the server names that are say Linux boxes and concatenate them into a different field.
Table A looks like this
Machine Name | Zone | Operating System
----------------------------------------
Server01 Zone A Linux
Server02 Zone B Linux
Server03 Zone A Windows
Server04 Zone C Windows
Server05 Zone B Solaris
Table B has the field I want to insert into: Affected_Machine_Names.
Now, I've tried looking through the Concatenate/Coalesce posts, but the SQL view in Access doesn't like the Declare statements. My VB skills suck badly and I can't seem to get the code to work in VB for Applications. Unfortunately, I can't get this database converted into our SQL farm cause I don't have a server available at the moment to host it.
Can anyone point me in the right direction?
You can use Concatenate values from related records by Allen Browne for this. Copy the function code from that web page and paste it into a new standard module. Save the module and give the module a name different from the function name; modConcatRelated would work.
Then I think you should be able to use the function in a query even though you're not proficient with VBA.
First notice I changed the field names in TableA to replace spaces with underscores. With that change, this query ...
SELECT
sub.Operating_System,
ConcatRelated("Machine_Name", "TableA",
"Operating_System = '" & sub.Operating_System & "'") AS Machines
FROM [SELECT DISTINCT Operating_System FROM TableA]. AS sub;
... produces this result set:
Operating_System Machines
Linux Server01, Server02
Solaris Server05
Windows Server03, Server04
If you can't rename the fields as I did, use a separate query to select the distinct operating systems.
SELECT DISTINCT TableA.[Operating System]
FROM TableA;
Save that as qryDistinctOperatingSystems, then use it in this version of the main query:
SELECT
sub.[Operating System],
ConcatRelated("[Machine Name]", "TableA",
"[Operating System] = '" & sub.[Operating System] & "'") AS Machines
FROM qryDistinctOperatingSystems AS sub;
This is a fairly basic VBA function that will loop through every row in a column, and concatenate it to a comma-delimited result string. i.e., for your example, it will return "Server01, Server02, Server03, Server04, Server05". (Don't forget to replace the column and table names)
Function ConcatColumn(OS As String) As String
Dim rst As DAO.Recordset
Set rst = CurrentDb.OpenRecordset("Select * from TableA")
Dim result As String
'For every row after the first, add a comma and the field value:
While rst.EOF = False
If rst.Fields("Operating System") = OS Then _
result = result & ", " & rst.Fields("MyValue")
rst.MoveNext
Wend
'Clean it up a little and put out the result
If Left(result, 2) = ", " Then result = Right(result, Len(result) - 2)
Debug.Print result
ConcatColumn = result
End Function
To use this,
1. ConcatColumn("Windows") will return "Server04, Server03"
2. ConcatColumn("Linux") will return "Server01, Server02"
3. ConcatColumn("Solaris") will return "Server05"
4. ConcatColumn("") will return "".
I made this package to make my sql task more dynamic:
Step1. I select SQLtext to run from my AccessTable and store in SQLStr var.
Step2. I run that Select statement stored in var SQLStr from Step1.
However I can run Step1 only if I used DataType = Object, and I can run Step2 only if i use DataTYpe = String, I played with it and verified this 100$.
How I can solve this problem, can I do some convert? of datatypes, my query stored in Access DB type = Memo, as it quite long, and might have line breaks.
What is the trick ?? Please refer to pic below for all details.
** Please note that this problem only occurs for Access Memo Type field !!!!**
In other setup it should work with String type OK in Step1
In your first query, when you select SQLText, Cast it as a string (in the select statement) so that you can store it in a string variable.
If it is not possible to CAST the memo field to a string in the SELECT (I'm not familiar with Access), then you can iterate through the object variable in a foreach loop and store the value of the SQLText column in a string variable, and then proceed to step 2 using that.
IF neither of those work, as a brute force method, you can follow the solution in this thread to import the Access table to a Staging table on SQL Server that uses an nvarchar(max) field, which you should be able to select into a string variable with no problem.
I have a crosstab query which queries a bunch of locations and gets their measurement readings. I pivot on the measurement readings so I get a table which has all the measurements for a location/date combo on each line. This works fine for getting all the data. It also works fine for filtering on one value per field. i.e. WHERE LocationID = ? AND MeasureID = ? but what I really need is to have something like WHERE LocationID IN (?) AND MeasureID IN (?) where ? is an array (or whatever gets to job done. Is this possible?
On my forms I'm using a DAO.QueryDef object to build my recordsets. I'd like to avoid building the entire query string in VBA if possible, mostly because this particular query is pretty long and I'd rather it live in a view and not a code module. With that said I can build it all in VBA but it's just not the desired solution.
You can always use replace.
sSQL = "SELECT lots of sql WHERE LocationID IN (qqlocidqq)"
sSQLWithLoc = Replace (sSQL, "qqlocidqq", "1,2,3,4")
Dim qdf As QueryDef
'A query that exists
Set qdf= CurrentDB.QueryDefs("MyJunkQuery")
'Permanently change the sql of that query
qdf.SQL = sSQLWithLoc
Looking into this a little further, it may suit you to use Instr, like so:
SELECT Table1.LocationID
FROM Table1
WHERE InStr([#List],[LocationID])>0
Tested like so:
PARAMETERS Number_List Text(50);
TRANSFORM Count(Table1.AKey) AS CountOfAKey
SELECT Table1.AText
FROM Table1
WHERE InStr([Number_List],[ANumber])>0
GROUP BY Table1.AText
PIVOT Table1.ANumber;
Where Table1 consists of fields AKey, AText, and ANumber. Number_List is a comma separated list of numbers supplied by a parameter. Instr checks for the existence of ANumber from Table1 in the supplied parameter.
There is a problem with overlap 1,2,12, but a creative use of commas may suit:
WHERE InStr("," & [Number_List] & "," , "," & [ANumber] & ",")>0
Of course the delimiter does not have to be a comma, | is often useful.
Any help that can be provided to a Access and VB noob would be greatly appreciated. What I'm trying to do is concatenate the values from one table and insert it as a comma delimited value into a field in another table. I'm trying to take all the server names that are say Linux boxes and concatenate them into a different field.
Table A looks like this
Machine Name | Zone | Operating System
----------------------------------------
Server01 Zone A Linux
Server02 Zone B Linux
Server03 Zone A Windows
Server04 Zone C Windows
Server05 Zone B Solaris
Table B has the field I want to insert into: Affected_Machine_Names.
Now, I've tried looking through the Concatenate/Coalesce posts, but the SQL view in Access doesn't like the Declare statements. My VB skills suck badly and I can't seem to get the code to work in VB for Applications. Unfortunately, I can't get this database converted into our SQL farm cause I don't have a server available at the moment to host it.
Can anyone point me in the right direction?
You can use Concatenate values from related records by Allen Browne for this. Copy the function code from that web page and paste it into a new standard module. Save the module and give the module a name different from the function name; modConcatRelated would work.
Then I think you should be able to use the function in a query even though you're not proficient with VBA.
First notice I changed the field names in TableA to replace spaces with underscores. With that change, this query ...
SELECT
sub.Operating_System,
ConcatRelated("Machine_Name", "TableA",
"Operating_System = '" & sub.Operating_System & "'") AS Machines
FROM [SELECT DISTINCT Operating_System FROM TableA]. AS sub;
... produces this result set:
Operating_System Machines
Linux Server01, Server02
Solaris Server05
Windows Server03, Server04
If you can't rename the fields as I did, use a separate query to select the distinct operating systems.
SELECT DISTINCT TableA.[Operating System]
FROM TableA;
Save that as qryDistinctOperatingSystems, then use it in this version of the main query:
SELECT
sub.[Operating System],
ConcatRelated("[Machine Name]", "TableA",
"[Operating System] = '" & sub.[Operating System] & "'") AS Machines
FROM qryDistinctOperatingSystems AS sub;
This is a fairly basic VBA function that will loop through every row in a column, and concatenate it to a comma-delimited result string. i.e., for your example, it will return "Server01, Server02, Server03, Server04, Server05". (Don't forget to replace the column and table names)
Function ConcatColumn(OS As String) As String
Dim rst As DAO.Recordset
Set rst = CurrentDb.OpenRecordset("Select * from TableA")
Dim result As String
'For every row after the first, add a comma and the field value:
While rst.EOF = False
If rst.Fields("Operating System") = OS Then _
result = result & ", " & rst.Fields("MyValue")
rst.MoveNext
Wend
'Clean it up a little and put out the result
If Left(result, 2) = ", " Then result = Right(result, Len(result) - 2)
Debug.Print result
ConcatColumn = result
End Function
To use this,
1. ConcatColumn("Windows") will return "Server04, Server03"
2. ConcatColumn("Linux") will return "Server01, Server02"
3. ConcatColumn("Solaris") will return "Server05"
4. ConcatColumn("") will return "".
I am using Access 2007 and have some linked tables to a mySQL database. I am using DAO to insert a record into a mySQL linked table and trying to retrieve the inserted PK using Select ##identity, but that select is returning 0.
Dim sql As String
Dim oDB As Database
Set oDB = CurrentDb
sql = "INSERT INTO Quotes ( CustomerID ) SELECT 1 AS Expr1;"
oDB.Execute sql
If oDB.RecordsAffected <> 1 Then
MsgBox "cannot create new quote"
Exit Function
End If
Dim rsNewID As DAO.Recordset
Set rsNewID = oDB.OpenRecordset("SELECT ##IDENTITY") ' Create a recordset and SELECT the new Identity
Dim intNewID As Long
intNewID = rsNewID(0).Value ' Store the value of the new identity in variable intNewID
'This value is 0, why?
I've seen another question like this, that has not been satisfactorily answered for me
SELECT LAST_INSERT_ID()
fredrik gets partial credit, for the mySQL statement. It's important to note that I am using DAO, so statements are processed by the JET engine and it does not support this statement. This needs to be run as a pass through query in Access in order to work though. After I made a pass through query with fredrik's select statement, that did the trick. I called this Access passthrough query from my DAO code and it worked.
I have not used mysql. So, translate what I say for mysql.
Is CustomerID an identity column (i.e. does it generate ID on its own)?
If so, use the function that returns the last generated ID.
##Identity function is what people use in SQL Server. I don''t know of equivalent in mysql.
See this
Looking at the code above, you need not open the 2nd recordset. The rsNewID1 should help you get the last inserted ID.
Hope this helps.