I have an MS Access db. I am writing an application in C# to access it. I have a field "FileName" of type "Short Text in MS Access. Data in FileName field is like "Test 11-12-2004 15.11.15".
Using a Date Range, I got to search records based on FileName field. I am not able to get - How do I compare the date of this format and retrieve the records ? FileName is a Text type and date is a substring of it. Retrieving only the date part and comparing with >= beginDate && <= endDate seems like a puzzle to me.
Can anyone suggest how do I write SQL query to perform this date range comparision and retrieve those records - "Select * from TestHead where FileName......" ????
Any help is appreciated.
Thanks a lot,
In your C# code, as you are going through the records, I'd split the string like this:
char[] delimiters = {' '};
string[] FileNameParts = FileName.Split(delimiters);
This will result in an array FileNameParts, the second element of which will contain the date, which you can convert to an actual date for use in the query:
DateTime FileNameDate = Convert.ToDateTime(FileNameParts(1))
Something along the lines of:
sSQL = "SELECT * FROM Table WHERE " & beginDate & " <= " & FileNameDate
I see this as preferable to adding a column to your table that contains the date substring of the FileName field, because then you constantly need to be updating that column whenever existing records are modified or new records are added. That means more clutter on the C# side, or an UPDATE query on the Access side which at least needs to get called periodically. Either way it would be more communication with the database.
Related
Access 2013 - Reference an Unbound text box on a Form
I am currently trying to use an unbound text box [Text161] on a Form name [DCM_Gap_Servers] to sort information through a table. I want the query that I created to be able to take the users input from [DCM_Gap_Servers]![Text161] as the field that is being sorted from the table names 'Server'.
This is the SQL I am using right now in the query:
SELECT * FROM Servers WHERE "Forms![DCM_Gap_Servers]![Text161]" IS NULL
** I have already Tried:
"Forms![DCM_Gap_Servers]![Text161]" ; (Forms![DCM_Gap_Servers]![Text161]); Forms.[DCM_Gap_Servers]![Text161]
This will work at any time if I replace the Text Box reference with the actual Field name I am using, but since there are hundreds of combinations of fields, I need the reference to work.
I have looked all over, and I can't seem to find the correct answer. I am willing to do it in VBA if needed, whatever it takes to get the filtering done correctly.
Thank You.
It is:
SELECT * FROM Servers WHERE Forms.[DCM_Gap_Servers].[Text161] IS NULL
but that will just select all records whenever your textbox is Null.
So it rather is:
SELECT * FROM Servers WHERE SomeField = Forms.[DCM_Gap_Servers].[Text161]
To use the form value as a field name, you must use concatenated SQL:
strSQL = "SELECT * FROM Servers WHERE " & Forms![DCM_Gap_Servers]![Text161].Value & " IS NULL"
This you might pass to the SQL property of an existing query object:
MyQueryDef.SQL = strSQL
Or:
Constant SQL As String = "SELECT * FROM Servers WHERE {0} IS NULL"
FieldName = Forms![DCM_Gap_Servers]![Text161].Value
MyQueryDef.SQL = Replace(strSQL, "{0}", FieldName)
Of course, take care the the field name isn't a zero length string.
I have three date columns. My report has 6 parameters: start and end date range for all three columns. Currently user has to select all date range but what if I want to allow user to only select one date range at a time. I cannot do "allow NULL values" option in the parameter because that see it as a field containing null value. I don't think it's possible to allow user to select only one parameter at a time so I'm trying an approach where there will be three parameters: one will consists of date field names. And rest two are based on date range of the field that is select from previous parameter. For example user selects a date field name from first and then date parameters will be cascaded and grab a value of date field based on the date field name that is selected in previous parameter. But I'm not sure exactly how to approach this. Any ideas?
I do that in some of my reports. The first parameter is "Does the range apply to A, B, or C" and the second and third parameters are the start and end data respectively. Well, I use integers, but dates should work the same as long as you format them.
The way it works, is you set the query in your dataset to be a function, and build it as mostly a quote but with the parameter values substituted in. A typical one might be
= "SELECT * FROM dbo.Trips WHERE " + Parameters!WhatField.Value + " between '" + FormatDateTime(Parameters!StartDate.Value, dateformat.shortdate) + "' and '" + FormatDateTime(Parameters!EndDate.Value, dateformat.shortdate) + "'"
Your parameter "WhatField" is a drop down list with 3 permitted values, make the value be the field name and the display be what your user wants to see as a description of the field.
I think you have to set the query for delayed evaluation somewhere (but I can't spot where right now, so maybe I'm mis-remembering), and you should set default values for your parameters that don't crash your report, but other than that it's fairly straightforward.
Oh, and to make the query a function it's just like a text query but hit the button to the right of the text box - it has a "fx" on it
If you need an even more complex query, you can put the whole query text in code (off the report properties) and call that function from the "fx" button to generate your query string.
I have a db in Access and I'm trying to get a textbox to run my query and pass an other bounded textbox's value in as the criteria in DLookUp. I have the query running in design view and when I enter the criteria directly it returns the correct results. When I open the report it gives me the sum of all the possible rows. In other words it doesn't filter the rows.
I haven't used Access in about twelve years, thankfully, and everything I've done up to this point has been tutorial/example patchwork, but here it is...
SQL Query:
SELECT Sum(IIf(Attended=-1,1,0)) AS attendance
FROM Students_Classes_Attendance
WHERE (((CStr([Students_Classes_Attendance].[Class_Id]))=[classId]));
DLookUp as Control Source:
=DLookUp("[Total Attendance by Class]![attendance]",
"[Total Attendance by Class]",
"[Class_Id] =" & [Class_Id])
I'm lost at the moment. I'm guessing that the value isn't there before the query fires and since the criteria is an optional parameter that it's being passed null, but I would hope you'd get an error from that. Not that #Error is very meaningful anyway.
Does anyone know for certain the problem and the best way to correct it? Thanks.
Edit:
I did the changes recommended in the answer so now my DLookUp looks like...
=DLookUp("[attendance]",
"[Total Attendance by Class]",
"[Class_Id] =" & [Class_Id])
...still returns the total for all rows. Removing the criteria completely makes no difference either, which returns me to thinking it has something to do with the bound textbox not having a value.
DLookup uses the following syntax:
Syntax for numerical values:
DLookup("FieldName" , "TableName" , "Criteria = n")
Syntax for strings: (note the single apostrophe before and after the string value)
DLookup("FieldName" , "TableName" , "Criteria= 'string'")
Syntax for dates: (note the # before and after the date value)
DLookup("FieldName" , "TableName" , "Criteria= #date#")
I believe you just need to remove the table name from the first parameter. Try this:
=DLookUp("[attendance]", "[Total Attendance by Class]", "[Class_Id] = " & [Class_Id])
Keep in mind that if Class_Id is a Text Field, you need to surround it by single quotes:
=DLookUp("[attendance]", "[Total Attendance by Class]", "[Class_Id] = '" & [Class_Id] & "'")
Background: Im busy with a research, in which I receive data stored in a oracle database. I myself use an Access database to store the data from the oracle database (and as well data from other sources, not relevant for this question)
The data from the oracle database is given to me in access format. Then I run the following query to retrieve the "oracle data" and insert (or update if the row already excist) into my own access database.
The oracle database export saved it's dates in text format, I have date formats in my own database, so I use a VBA function to transform the texts in dates.
My question: Can I join on a string and a date if the string is transformed to a date? How should I proceed?
UPDATE [TABLE1] INNER JOIN [URI_to_oracle_export.mdb].[TABLE2]
ON ([TABLE1].PT=[TABLE2].PT)
AND ([TABLE1].DCMDATE=toDateFunction([TABLE2].DCMDATE))
AND ([TABLE1].CPEVENT=[TABLE2].CPEVENT) SET ...the rest of the SQL..
My toDateFunction:
Function toDateFunction(input As String)
toDateFunction= CDate(Right(input , 2) & "/" & Mid(input , 5, 2) & "/" & Left(input , 4))
End Function
So based on your conversion function it looks as though the Oracle text format you are receiving is YYYYMMDD, for using type conversions for a join in this case I would prefer to work the other way round and transform my access value to text e.g:
WHERE OracleTable.Date = Format(AccessTable.Date, "YYYYMMDD")
Or
INNER JOIN OracleTable ON OracleTable.Date = Format(AccessTable.Date, "YYYYMMDD")
You could still do it in reverse and convert your Oracle value to a date if you wanted which would be more like:
WHERE DateSerial(Left(OT.Date,4),Mid(OT.Date,5,2),Right(OT.Date,2)) = AT.Date
When building your date value literally I prefer using DateSerial to CDate
I've had a look around but cannot find the issue with this SQL Statement:
strSQL = "SELECT Directory.DisplayName, Department.DisplayName, Call.CallDate, Call.Extension, Call.Duration, Call.CallType, Call.SubType FROM (((Department INNER JOIN Directory ON Department.DepartmentID = Directory.DepartmentID) INNER JOIN Extension ON (Department.DepartmentID = Extension.DepartmentID) AND (Directory.ExtensionID = Extension.ExtensionID)) INNER JOIN Site ON Extension.SiteCode = Site.SiteCode) INNER JOIN Call ON Directory.DirectoryID = Call.DirectoryID WHERE (Call.CallDate)>=27/11/2012"
Regardless of what I change the WHERE it always returns every single value in the database (atleast I assume it does since excel completely hangs when I attempt this) this SQL statement works perfectly fine in Access (if dates have # # around them). Any idea how to fix this, currently trying to create a SQL statement that allows user input on different dates, but have to get over the this random hurdle first.
EDIT: The date field in the SQL Database is a DD/MM/YY HH:MM:SS format, and this query is done in VBA - EXCEL 2010.
Also to avoid confusion have removed TOP 10 from the statement, that was to stop excel from retrieving every single row in the database.
Current Reference I have activated is: MicrosoftX Data Objects 2.8 Library
Database is a MSSQL, using the connection string:
Provider=SQLOLEDB;Server=#######;Database=#######;User ID=########;Password=########;
WHERE (Call.CallDate) >= #27/11/2012#
Surround the date variable with #.
EDIT: Please make date string unambiguous, such as 27-Nov-2012
strSQL = "SELECT ........ WHERE myDate >= #" & Format(dateVar, "dd-mmm-yyyy") & "# "
If you are using ado, you should look at Paramaters instead of using dynamic query.
EDIT2: Thanks to #ElectricLlama for pointing out that it is SQL Server, not MS-Access
strSQL = "SELECT ........ WHERE myDate >= '" & Format(dateVar, "mm/dd/yyyy") & "' "
Please verify that the field Call.CallDate is of datatype DATETIME or DATE
If you are indeed running this against SQL Server, try this syntax for starters:
SELECT Directory.DisplayName, Department.DisplayName, Call.CallDate,
Call.Extension, Call.Duration, Call.CallType, Call.SubType
FROM (((Department INNER JOIN Directory
ON Department.DepartmentID = Directory.DepartmentID)
INNER JOIN Extension ON (Department.DepartmentID = Extension.DepartmentID)
AND (Directory.ExtensionID = Extension.ExtensionID))
INNER JOIN Site ON Extension.SiteCode = Site.SiteCode)
INNER JOIN Call ON Directory.DirectoryID = Call.DirectoryID
WHERE (Call.CallDate)>= '2012-11-27'
The date format you see is simply whatever format your client tool decides to show it in. Dates are not stored in any format, they are effectively stored as a duration since x.
By default SQL Uses the format YYYY-MM-DD if you want to use a date literal.
But you are much better off defining a parameter of type date in your code and keeping your date a data type 'date' for as long as possible. This may include only allowing them to enter the date using a calendar control to stop ambiguities.