Uniqueidentifier Field In SQL With Null Value - Cannot Detect This In Code... Why?
Nov 3, 2007
OK, I use asp.net membership and have created a new table that links together related users by use of the uniqueidentifier field as a foreign key. However, it is possible to link to a not-yet existent user (by their email) so that when that user creates an account and gets a guid, it will be updated into my table of related users and finalise the link. Trouble is, I'm trying to stop people adding the same "pending user" multiple times, so in my BLL logic I look for the entered email address for the current user and I want to check on the foreign key (the GUID field) so that I can tell the user that they've already added this user, but they haven't signed up yet (if they haven't got a foreign user key with a guid in it, they haven't signed up yet).
However, when I check the foreign key guid value (shows as null in sql enterprise manager) for null values, it never goes down the "true" logic channel... what I mean is that I've debugged it, hovered over the item I've read (it says it is system.dbnull, which it is) and yet when I do "isDBNull(myGUID.Value)" it never equates to true!
Another table with an uniqueidentifier which references the user iD
I want to set the value of the iD in one of the entries in the second table to null.
I tried this: string assigned is null, i am passing this as a method parameter ............... string queryString = "UPDATE [table2] SET AssignedUserId=@assigned WHERE ProblemId = @id"; System.Data.IDbCommand dbCommand = new System.Data.SqlClient.SqlCommand(); ................... System.Data.IDataParameter dbParam_au_pr = new System.Data.SqlClient.SqlParameter(); dbParam_au_pr.ParameterName = "@assigned"; if (assigned == null) { dbParam_au_pr.Value = null; } else { dbParam_au_pr.Value = assigned; } dbParam_au_pr.DbType = System.Data.DbType.String ; dbCommand.Parameters.Add(dbParam_au_pr);
I also tried using "" instead of null, or not using that "if" statement at all. I get an error that says:
Parameterized Query '(@id nvarchar(1),@assigned nvarchar(4000))UPDATE [tracker_Probl' expects parameter @assigned, which was not supplied. Please help with this as soon as possible.Thanks
I have a concated code from excel when I have to pick some values for db update, the problem is when one field is empty, this field is date type and I don't now how can I validate if UserDate_02 field is null or not, I get it from a cell in excel and later when I get all the code I update the db, this is the line :
UPDATE ITEMS SET UserField_01='AA',UserDate_01='01/28/2014',UserYesNo_01=1,UserDate_02=''WHERE LotNumber='134034143017297'and ItemCode='G22221'
Hi,I want to check with VB.net whether a field in a SQL-table is NULL or not.This code doesnot work:If xxx = NULL then<statements>End IfI got the error, that NULL is not supported ?How do I code the check ???Help is appreciated, Gr.
Hi all, I have a problem about a query to update a table
UPDATE Email SET EmailDT='31 Mar 2004' WHERE Idx={BDF51DBD-9E4F-4990-A751-5B25D071E288}
where Idx field is a uniqueidentifier type and EmailDT is datetime type. I found that when this query calling by a VB app. then it have error "[Microsoft][ODBC SQL Server Driver]Syntax error or access violation" and i have tried again in Query Analyzer, same error also occur, the MS SQL server is version 7. Please help. thanks.
Hi all,I have this code that I use for my Search function:SELECT DISTINCT [MUSIC_TITLE], [MUSIC_ORIGINAL_SINGER], [MUSIC_PERFORMER]FROM t_musicWHERE (@MUSIC_TITLE IS NULL OR [MUSIC_TITLE] LIKE '%' + @MUSIC_TITLE + '%') AND (@MUSIC_ARTIST IS NULL OR ([MUSIC_ORIGINAL_SINGER] LIKE '%' + @MUSIC_ARTIST + '%' OR [MUSIC_PERFORMER] LIKE '%' + @MUSIC_ARTIST + '%')) But right now if I don't enter anything in one of the textbox (2 have two, either of them can be left empty), the above Sql statement doesn't return anything since ADO.NET can't tell an empty textbox and treat it at null... So anyone please help me how to detect an empty textbox and set that to null for the above SQL statement to work. (It work in SQL Manager Studio, when I set one of the parameter = null.) I'm very new to ASP.NET stuffs, so if someone can help me to convert that function to code-behind and help me to call it from the .aspx, that would be even better as I don't want to put the code in my .aspx page... But I'm not quite there yet. Thank you all,Kenny.
As you know we can get the last identity by using these functions:@@IDENTITY, IDENT_CURRENT( '[Table_Name]' ) And More.But if I set my primary key datatype to uniqueidentifier, I Can't get the last GUID inserted by SQL.Anyone have any idea?Reach me at my blog: http://ramezanpour.spaces.live.com
I have several tables a varbinary column in a database. They have names like CSB_BLOB or OBJECT_BLOB. Now I am having intermittent success with getting the data out.
For example this query returns readable text from this data.
0x46726F6D3A20226465616E6E6167726.....etc --data as stored in the column
SELECT CAST(CSB_BLOB AS VARCHAR(MAX)) AS 'Message' FROM OBJECT_BLOB
However this column has the following query results.
0x0001000000FFFFFFFF01000000000000000C....etc. --data as stored in column
--this query returns empty result
SELECT (CSB_BLOB AS VARCHAR(MAX)) AS 'Message' FROM CSB_STATUS_LOG
--this query returns no change???
SELECT CONVERT(VARCHAR(MAX), CONVERT(VARBINARY(MAX), CSB_BLOB, 2), 2) FROM CSB_STATUS_LOG 0001000000FFFFFFFF01000000000000000C....etc
Obviously there is a difference between the two but I am not educated enough to interpret this difference. What do I need to learn / read so I can look at the data in one of these BLOB columns and know how to convert it to something meaningful?
Something like:
1. Try to cast as varchar to see if it is text. 2. Turn into a byte array and see if it is a jpg 3. Turn into a byte array and see if it is a pdf 4. Convert it to hex and then cast as varchar 5. etc....
I am new at ASP.net and I am having problems inserting data using C# in ASP.netI have created a table named "Profile" in the MS sql server database named "MyDataBase". There is a field named "ID" that has data type 'uniqueidentifier'.I am confused how to INSERT data into this data field. I have used MS Access and MYSQL in which there is an option of auto increment so we don't a unique identifier for each record.Please tell me what can I do to If I want to have a uniqueidentifier for each new record I INSERT in the "Profile" table of MS sql server database.While trying to insert, I get following errorsCannot insert the value NULL into column 'ID'and I don't know how I can insert something in this field that is of value type unique identifier.Please help me I will be very thankfull of you.
I need to pass in null/blank value in the date field or declare the field as string and convert date back to string.
I tried the 2nd option but I am having trouble converting the two digits of the recordset (rs_get_msp_info(2), 1, 2))) into a four digit yr. But it will only the yr in two digits. The mfg_start_date is delcared as a string variable
option 1 I will have to declare the mfg_start_date as date but I need to send in a blank value for this variable in the stored procedure. It won't accept a null or blank value.
Hi, I'm trying to extend the usage of the code below. This method returns a variable of type SQLParameter and what I want is to accomodate even a check for a null in the parameter. This is a code which I got from one of my co-workers who isn't anymore working here. Any help would be appreciated. I do not want to throw an exception here when a field's type doesn't fall into one of the categories below. The method where this methos is called is the first part of my below code. Any help would be appreciated.
Part 1
private void AddCommandParameters(SqlCommand Comm, string sProcName, ArrayList aParams) { string sSQL = "sp_helptext @objname = '" + sProcName + "'"; SqlDataReader dr = this.GetDataReader(sSQL); int i = 0;
if(dr.Read()) { while(dr.Read()) { //CLOSING PARENTHESIS //When at the closing paren of the stored procedure's variable //declaration, quit adding parameters. if(dr[0].ToString().Trim() == ")") { break; } //ENDING PARENTHESIS //When at the closing paren of the stored procedure's variable //declaration, do nothing and skip to next record. else if(dr[0].ToString().Trim() == "(") { //Nada } //PARAMETERS //Add all the parameters listed in the stored procedure's variable //declaration. else { string [] sParamDef = dr[0].ToString().Trim().Split(Convert.ToChar(" ")); int cs = sParamDef.Length; string st = sParamDef[0].ToString().Trim(); SQLParameter s = GetSQLParameter(sParamDef[0].ToString().Trim()); Comm.Parameters.Add(sParamDef[0], s.Type, s.Size); Comm.Parameters[sParamDef[0]].Value = aParams[i]; i++; } } } else { throw(new Exception("Stored Procedure: " + sProcName + " NOT FOUND.")); } dr.Close(); }
I have a table, named systems, with fields as follows.
field datatype ___________________ system varchar(50) modelID int .... .... ... .... etc...
The modelID field is related to the Models table. Therefore, the value it expects is a number that already exists in a Models.modelID field.
In the systems table, I allow nulls for the model ID field. If I edit the table directly through SQL front end it allows me to enter a system name for example and leave modelID value as NULL.
My problem occurs when I try inserting into the table from ASP. Whether I leave the value I'm passing to the stored procedure for insert blank or NULL it gives me problems.
Is this a typical issue that can be resolved with a simple property change?
Please help me resolve this, I need to have the ability to leave certain fields empty even though they are related to other tables. Is that possible?
Hello all, Can some one help me with this issue. It seems to be a common question and I have tried a lot of options but nothing seems to work for me. I have a text box and this is linked to ajax calendar extender. They get a date and I am inserting/updating the date in a sql 2000 database using a stored procdure. This is the code I use to grab the data from my web form If txtTrimsEntryDate.Text = String.Empty Then _oTrim.TrimsEntryDate = System.Data.SqlTypes.SqlDateTime.Null Else_oTrim.TrimsEntryDate = CDate(txtTrimsEntryDate.Text) End If If txtEstCompletion.Text = String.Empty Then _oTrim.EstCompletionDate = System.Data.SqlTypes.SqlDateTime.Null Else_oTrim.EstCompletionDate = CDate(txtEstCompletion.Text) End If If txtProjectClosedDate.Text = String.Empty Then _oTrim.CloseDate = System.Data.SqlTypes.SqlDateTime.Null Else_oTrim.CloseDate = CDate(txtProjectClosedDate.Text) End If _oTrim.InsertOrUpdateAProject()
This is the code for the stored Procedure Dim oSql As clsSqlServer = Nothing oSql = New clsSqlServer(AppSettings(_dbName))oSql.AddParameter("@projTrimsEntryDate ", _trimsEntryDate, SQLDataType.SQLDateTime, ParameterDirection.Input) oSql.AddParameter("@projStartDate", _startDate, SQLDataType.SQLDateTime, ParameterDirection.Input)oSql.AddParameter("@estCompletionDate", _estCompletionDate, SQLDataType.SQLDateTime, ParameterDirection.Input) oSql.AddParameter("@closeDate", _closeDate, SQLDataType.SQLDateTime, ParameterDirection.Input) Now when it inserts or updates if the value is null then it inserts "01/01/1900" in the database. I want the value to be Null in database. Is there a way to do this.
Is there any way of excluding an entire row if a particular field contains a null value? Even if other fields in the row aren't null... This is in SQL Server 2005
I would like to force a column to be null all the time. I cannot alter the table structure or alter the code that inserts data.
create table dbo.tblCustomer ( CID int IDENTITY(1,1) not null, Fnamevarchar(20) not null, Lnamevarchar(20) not null, Extravarchar(20) null
[Code] ....
So when this is executed the field Extra is always NULL
INSERT INTO tblCustomer (Fname, Lname, Extra) VALUES ('bob', 'smith', 'ignore'), ('jane', 'doe', 'empty') update dbo.tblCustomer set Extra = 'something'
If I've understood After triggers correctly the data will be written and the trigger will fire and overwrite. To avoid 2 writes
I could create an INSTEAD OF trigger
CREATE TRIGGER TR_I_Customer ON tblCustomer INSTEAD OF INSERT AS BEGIN SET NOCOUNT ON INSERT INTO tblCustomer (Fname, Lname, Extra) SELECT Fname, Lname, NULL FROM Inserted END
This will not write the "extra" field twice. However if a new Nullable column were added; it would be v.easy to forget to update the Instead Of trigger. Everything would still work OK but I would be effectively ignoring the new column as well.
What I would like in the instead of trigger is do something like this...
UPDATE INSERTED SET Extra=NULL
Continue with insert without supplying column /value list.
What would be the best way of achieving this, trigger is the only way I could think of?
Caseinfo shows when a particular case entered and exited a particular project. If the project hasn't ended yet, then the end date is NULL.
Steps shows the steps the case has gone through and the dates of those particular steps.
I need to join the tables to show the steps the case went through during a particular project, but I'm having trouble with the NULL values in the end dates.
If I join the tables so that the step date is between the start and end dates of the project, then I get no step information for the cases where the end date is NULL (that is, where the project hasn't ended yet).
Does anybody have any ideas?
Here are my tables, the query that shows the main idea (with the wrong result), and my expected results.
insert @caseinfo select 10, '2006-12-23', '2006-12-27' union all select 20, '2006-12-23', NULL union all select 30, '2006-12-23', NULL union all select 40, '2007-1-15', '2007-3-4'
insert @steps select 10, 1, '2006-12-24' union all select 10, 2, '2007-1-3' union all select 10, 3, '2007-2-5' union all select 20, 1, '2006-12-26' union all select 20, 2, '2007-1-7' union all select 20, 3, '2007-1-9' union all select 30, 1, '2007-1-14' union all select 40, 1, '2007-1-23' union all select 40, 2, '2007-3-2' union all select 40, 3, '2007-4-16'
--- the main idea (with the wrong results)
select * from @caseinfo c left join @steps s on s.caseid = c.caseid and s.stepdate between c.startdate and c.enddate
insert @expresult select 10, '2006-12-23', '2006-12-27', 1, '2006-12-24' union all select 20, '2006-12-23', NULL, 1, '2006-12-26' union all select 20, '2006-12-23', NULL, 2, '2007-1-7' union all select 20, '2006-12-23', NULL, 3, '2007-1-9' union all select 30, '2006-12-23', NULL, 1, '2007-1-14' union all select 40, '2007-1-15', '2007-3-4', 1, '2007-1-23' union all select 40, '2007-1-15', '2007-3-4', 2, '2007-3-2'
hi guys, I'm using SQLServer 2005 and I was wondering how I check if some variable is null or not? I tryied to do as the code show but it doesn't work:
declare @number int
set @number = (select number from numbers where number_id = 1)
I have an SQL database table that includes a BirthDate field. I would like to have this field as optional when adding a record, but, SQL insists on throwing an exception if the field is null.
After the "DAYS" column, some fields are coming null. We don't want it to come null. Beside this, i.e; in the "MONDAY"column, the same "NAMESURNAME" is coming more then one. How can I do the grouping by "NAMESURNAME"?
MachType DayPeriod Monday Tuesday Wednesday Thursday Friday Saturday Negative- || NIGHT || NULL || CAN AK || NULL || FİRDEVS ATEŞ || NULL || NULL Negative- || NIGHT || NULL || NULL || CEM TEK || NULL || NULL || NULL Negative- || NIGHT || NULL || NULL || NULL || FİRDEVS ATEŞ || MÜKREMİN EKELİK || NULL Negative- || NIGHT || NULL || CAN AK || CEM TEK || FİRDEVS ATEŞ || NULL || NULL Negative- || NIGHT || NULL || NULL || NULL || NULL || ÖMER CANOĞLU || NULL
select MachineType,DAYS,
CASE WHEN DIALYSISDAY= 'MONDAY'THEN NAMESURNAME END AS MONDAY,
CASE WHEN DIALYSISDAY= 'TUESDAY' THEN NAMESURNAME END AS TUESDAY,
CASE WHEN DIALYSISDAY= 'WEDNESDAY' THEN NAMESURNAME END AS WEDNESDAY,
CASE WHEN DIALYSISDAY= 'THURSDAY' THEN NAMESURNAME END AS THURSDAY,
CASE WHEN DIALYSISDAY= 'FRIDAY' THEN NAMESURNAME END AS FRIDAY,
CASE WHEN DIALYSISDAY= 'SATURDAY' THEN NAMESURNAME END AS SATURDAY
from
(SELECT SICK.MACHINETYPE,SICK.NAMESURNAME ,
CASE
WHEN SUBSTRING(DAYPERIOD, DATEPART(dw, SEANCE.SEANCEDATE), 1)= 'N' THEN 'NIGHT' ELSE '' END AS DAYS,
CASE
WHEN SICK.MACHINETYPE= 1 THEN 'Negative-'
WHEN SICK.MACHINETYPE= 2 THEN 'B(+)'
WHEN SICK.MACHINETYPE= 3 THEN 'C(+)B(+)'
WHEN SICK.MACHINETYPE= 4 THEN 'C(+)' END AS MachineType,
CASE
WHEN (DATEPART(dw, SEANCE.SEANCEDATE)) = 1 THEN 'MONDAY'
WHEN (DATEPART(dw, SEANCE.SEANCEDATE)) = 2 THEN 'TUESDAY'
WHEN (DATEPART(dw, SEANCE.SEANCEDATE)) = 3 THEN 'WEDNESDAY'
WHEN (DATEPART(dw, SEANCE.SEANCEDATE)) = 4 THEN 'THURSDAY'
WHEN (DATEPART(dw, SEANCE.SEANCEDATE)) = 5 THEN 'FRIDAY'
WHEN (DATEPART(dw, SEANCE.SEANCEDATE)) = 6 THEN 'SATURDAY' END AS DIALYSISDAY
FROM SEANCE,SICK WHERE SUBSTRING(DAYPERIOD, DATEPART(dw, SEANCE.SEANCEDATE), 1)= 'N' and
SUBSTRING(SICK.EUCLID,1,5)= '18016' AND SEANCEDATEBETWEEN '20080301' AND '20080307'
AND SICK.EUCLID=SEANCE.EUCLID )AS T ORDER BY MachineType
I need to insert a null valvue when the user does not impute any text. here is my code If cell_phone.Text = "" Then cell_phone.Text = "dbnull.value" End IfDim mySqlConnection As New SqlConnection mySqlConnection.ConnectionString = ConfigurationManager.ConnectionStrings("Call_ListConnectionString").ConnectionString Dim strSQL As String = "INSERT INTO Employees(Clock_ID, Last_Name, First_Name, Cell_Phone, Home_Phone, Work_Phone, Email, Primary_Day_Phone, Primary_Night_Phone, Blackberry_Number) VALUES ('" & clock_id.Text & "','" & last_name.Text & "','" & first_name.Text & "','" & work_phone.Text & "','" & home_phone.Text & "','" & cell_phone.Text & "','" & email.Text & "','" & prime_day_lst.SelectedValue & "','" & prime_night_lst.SelectedValue & "','" & blackberry.Text & "')"Dim mySqlCommand As New SqlCommand(strSQL, mySqlConnection) mySqlConnection.Open() mySqlCommand.ExecuteNonQuery() mySqlConnection.Close() THanks Mike
I have a datetime field in a database which I am programmatically inserting values into. The field can be null or not null. However, I am having problems inserting NULL as part of my SQLCommand. The value is pulled from a text box (linked to a calendar extender) and when I select a value it is being inserted fine. If I just leave the box blank though, I want the field to be set to NULL. I have tried adding in ,DBNULL.Value, as part of my VALUES(…) string, but this throws an exception. I Have tried just inserting ‘’ but that also throws an exception (“The conversion of a char data type to a datetime data type resulted in an out-of-range datetime value�), so I don’t know how I can insert this value when the field is blank? Can anyone shed some light please? Thanks
hi all!I have a task, for example, to create a record for bill. I have table which represents this bill entity (Bill_ID, Amount, CreationDate, ExposureDate, PaymentDate)In table definition date fields allow null. I would like to create bill, which means insert record: (new_bill_id, 1000, 2007.12.11, null, null) But it couses exception. Smth like: System.Data.SqlTypes.SqlTypeException, date should be not null. How could I do it?Please advice!
Hi, All records of a table must be deleted if a field (field1) contains NULL or is made empty by a previous update command. I did this but it only works when the field is made empty, not when it contains NULL: dim field1 as string = ""...sql = "delete from mytable WHERE (field1=@field1)" comd = New SqlCommand(sql, oConnection) comd.Parameters.AddWithValue("@field1", field1) comd.ExecuteNonQuery() How can i do that? Thanks Tartuffe
Hi, I am building a website in ASP.net C# for a university project, and would like to search a table (Member) for a field (UserName) using a session variable Session["sUserName"]. If that field is null, then I would like to insert that session variable into the field to start to create a new user. However, I am getting errors saying that I am using invalid expression terms. My code is; //Create the Command, passing in the SQL statement and the ConnectionString queryString = "SELECT UserName FROM Member WHERE (UserName = @myUsername); "; SqlCommand cmd = new SqlCommand(queryString, sqlConn);cmd.Parameters.Add(new SqlParameter("@myUsername", Convert.ToString(Session["sUserName"]))); //If UserName is null, display confirmation, else display errorif (UserName == null) ; {UserNameCheckLabel.Text = "Username okay"; String queryString = "INSERT INTO Member (UserName) VALUES(@myUsername); ";SqlCommand cmd = new SqlCommand(queryString, sqlConn); cmd.Parameters.Add(new SqlParameter("@myUsername", Convert.ToString(Session["sUserName"]))); }else; {UserNameCheckLabel.Text = "That username is in use"; } I have a feeling I should be checking the database for the UserName, but I'm not sure whether to put this in the SELECT statement part or as a method... I would be most grateful for any advice! Many thanks, Chima
I am having a problem with an update statement. I am using compareallvalues with a SQL data source. When one of the old values is null the update does not go through. i.e. This does not work if something is NULL UPDATE myTable SET something = @somethingWHERE ID = @o_ID AND something = @o_something Thank You,Jason
