Cannot Update Records because of expression DataColumn

[Hemang Shah]

I have an expression DataColumn which combines "First Name" + "Last Name" to
display in the list box to select the name, who's record comes up.


But when I use the daDataAdapter.Update(dsDataSet, tblTableName); It gives
me an exception saying cannot update readonly expression type.

How do I fix this?!

Isn't Visual Studio a lot more powerful than access ? So far, I've found
serious limitation in the the controls of Visual Studio.. Like listbox &
ComboBox not being able to have multiple fields!...

There are 3rd party solutions but they all are very expensive..

Please let me know if there are any suggestion for my mentioned problem.

Thank You

HS

 

[Miha Markic [MVP C#]]

Hi Hemang,

How is your daDataAdapter configured?

 

[Sahil Malik]

Hemang,

For such situations, you have to resolve a bit away from point and click and
write code yourself.
Try specifying the Update statement for your data adapter by hand ..


- Sahil Malik
http://codebetter.com/blogs/sahil.malik/

 

[Hemang Shah]

Hello Miha

My DataAdapter called daClient is like this:

//

// daClient

//

this.daClient.DeleteCommand = this.sqlDeleteCommand2;

this.daClient.InsertCommand = this.sqlInsertCommand2;

this.daClient.SelectCommand = this.sqlSelectCommand2;

this.daClient.TableMappings.AddRange(new
System.Data.Common.DataTableMapping[] {

new System.Data.Common.DataTableMapping("Table", "tblClient", new
System.Data.Common.DataColumnMapping[] {

new System.Data.Common.DataColumnMapping("ClientID", "ClientID"),

new System.Data.Common.DataColumnMapping("LastName", "LastName"),

new System.Data.Common.DataColumnMapping("GivenName", "GivenName"),

new System.Data.Common.DataColumnMapping("Status", "Status"),

new System.Data.Common.DataColumnMapping("ReasonToCloseID",
"ReasonToCloseID"),

new System.Data.Common.DataColumnMapping("DOB", "DOB"),

new System.Data.Common.DataColumnMapping("Gender", "Gender"),

new System.Data.Common.DataColumnMapping("MaritalStat", "MaritalStat"),

new System.Data.Common.DataColumnMapping("ImmigStat", "ImmigStat"),

new System.Data.Common.DataColumnMapping("SIN", "SIN"),

new System.Data.Common.DataColumnMapping("HealthCard", "HealthCard"),

new System.Data.Common.DataColumnMapping("WorkPermit", "WorkPermit"),

new System.Data.Common.DataColumnMapping("Origin", "Origin"),

new System.Data.Common.DataColumnMapping("CameToCanada", "CameToCanada"),

new System.Data.Common.DataColumnMapping("FirstLang", "FirstLang"),

new System.Data.Common.DataColumnMapping("OtherLang", "OtherLang"),

new System.Data.Common.DataColumnMapping("ChildMinding", "ChildMinding"),

new System.Data.Common.DataColumnMapping("Education", "Education"),

new System.Data.Common.DataColumnMapping("Discipline", "Discipline"),

new System.Data.Common.DataColumnMapping("PrevOcc", "PrevOcc"),

new System.Data.Common.DataColumnMapping("PresOcc", "PresOcc"),

new System.Data.Common.DataColumnMapping("TargetOcc", "TargetOcc"),

new System.Data.Common.DataColumnMapping("WorkingNow", "WorkingNow"),

new System.Data.Common.DataColumnMapping("WorkingSince", "WorkingSince"),

new System.Data.Common.DataColumnMapping("WorkCDN", "WorkCDN"),

new System.Data.Common.DataColumnMapping("SourceIncome", "SourceIncome"),

new System.Data.Common.DataColumnMapping("Referal", "Referal"),

new System.Data.Common.DataColumnMapping("SocialWrk", "SocialWrk"),

new System.Data.Common.DataColumnMapping("ResumeLoc", "ResumeLoc"),

new System.Data.Common.DataColumnMapping("ResumeType", "ResumeType"),

new System.Data.Common.DataColumnMapping("PhoneType", "PhoneType"),

new System.Data.Common.DataColumnMapping("PhoneNum", "PhoneNum"),

new System.Data.Common.DataColumnMapping("AltPhoneType", "AltPhoneType"),

new System.Data.Common.DataColumnMapping("AltPhoneNum", "AltPhoneNum"),

new System.Data.Common.DataColumnMapping("Email", "Email"),

new System.Data.Common.DataColumnMapping("SingleMother", "SingleMother"),

new System.Data.Common.DataColumnMapping("LongTermGoal", "LongTermGoal"),

new System.Data.Common.DataColumnMapping("LongTermGoalComments",
"LongTermGoalComments"),

new System.Data.Common.DataColumnMapping("ShortTermGoal", "ShortTermGoal"),

new System.Data.Common.DataColumnMapping("ShortTermGoalComments",
"ShortTermGoalComments"),

new System.Data.Common.DataColumnMapping("NextStepComments",
"NextStepComments")})});

this.daClient.UpdateCommand = this.sqlUpdateCommand2;



My Expression DataColumn is defined as below in the form_load procedure:



private void frmClient_Load(object sender, System.EventArgs e)

{

DataColumn dcFullName = new DataColumn();

this.daClient.Fill(this.dsClient);

this.daChild.Fill(this.dsClient);

this.daClientAddress.Fill(this.dsClient);

dcFullName.DataType = System.Type.GetType("System.String");

dcFullName.ColumnName = "FullNameFN";

dcFullName.Expression = "GivenName + ' ' + LastName";

this.dsClient.tblClient.Columns.Add(dcFullName);

this.dvClient.Sort = "GivenName";

lstName.DataSource = dvClient;

lstName.DisplayMember = "dcFullName";

lstName.ValueMember = "ClientID";

lstName.SelectedIndex = 1;

}



I checked my autogenerated Update method, and it doesn't add the FullNameFN
in it either.

It acts funny, because the first time I click update, it works fine, the
second time, it throws an exception.



Any suggestion?

Hi Hemang,

How is your daDataAdapter configured?

--
Miha Markic [MVP C#] - RightHand .NET consulting & development
SLODUG - Slovene Developer Users Group
www.rthand.com

I have an expression DataColumn which combines "First Name" + "Last Name"
to display in the list box to select the name, who's record comes up.


But when I use the daDataAdapter.Update(dsDataSet, tblTableName); It
gives me an exception saying cannot update readonly expression type.

How do I fix this?!

Isn't Visual Studio a lot more powerful than access ? So far, I've found
serious limitation in the the controls of Visual Studio.. Like listbox &
ComboBox not being able to have multiple fields!...

There are 3rd party solutions but they all are very expensive..

Please let me know if there are any suggestion for my mentioned problem.

Thank You

HS

 

[Hemang Shah]

Hello Sahil

The update method doesn't include that expression column, I already checked
that.

Thanks