Fufill ONLY with ''False''

Question

Hi!

I need to understand one logic.

I have one database with two columns (Name and Absent) + one button.

What I need to do?

When I click one button its should this:

if you find in the ''Absent'' column, blank spaces (or blank cells). Fufill it ONLY with the word ''false''.

Name	Absent
Chairman	True
Chairman

Ruben	........
Shuman	True
Andrew	........

Then please anyone can help?

Vulpes · Answer

If 'Absent' is a character based column then this UPDATE statement should work: UPDATE MyTable SET Absent='False' WHERE ISNULL(Absent) OR Absent=''

Israel · Answer

@Vulpes You have a greatest understanding in the C#'s plate forme. I dont have any words to say...

Vulpes · Answer

Well it's only updating the ClickOut column because you've overwritten the other two UPDATE statements. You need to call ExecuteNonQuery after each one: comm.CommandText = UPDATE 1 SET Absent='Ausente' WHERE ISNULL(Absent) OR Absent='True'; comm.ExecuteNonQuery(); comm.CommandText = UPDATE 1 SET clock_In='Ausente' WHERE ISNULL(clock_In) OR clock_In=''; comm.ExecuteNonQuery(); comm.CommandText = UPDATE 1 SET clock_Out='Ausente' WHERE ISNULL(clock_Out) OR clock_Out=''; comm.ExecuteNonQuery();

Israel · Answer

The columns name was wrong. But I correct it now. But when click the message error doesnt appear. Its update only the clock_out column. What happen?

Israel · Answer

A operação tem que utilizar uma consulta actualizável. This word mean: The operation should use a query actualized.

Israel · Answer

@Vulpe This is one of the very importante code for me to learn. Firstly for what I need to do I do put it in the load event. But what kind of problem I meet now. Unfortunatly it's doesnt react (no error message... no buggs). Then I do drop here the whole code. But its gives this message: A operação tem que utilizar uma consulta actualizável : comm = new OleDbCommand(); conn.Open(); OleDbParameter ndays = new OleDbParameter(@ndays SqlDbType.NChar); comm.Parameters.Add(ndays); ndays.Value = ; comm.Connection = conn; comm.CommandText =  UPDATE 1 SET Absent='Ausente' WHERE ISNULL(Absent) OR Absent='True'; comm.CommandText =  UPDATE 1 SET clock_In='Ausente' WHERE ISNULL(clock_In) OR clock_In=''; comm.CommandText =  UPDATE 1 SET clock_Out='Ausente' WHERE ISNULL(clock_Out) OR clock_Out=''; comm.ExecuteNonQuery(); conn.Close();

Vulpes · Answer

Even if your syntax were correct you can't combine these particular updates in that way because you might end up setting all 3 columns to 'False' even though one (or two) of them is neither null nor empty. You need to do 3 separate UPDATE statements instead: UPDATE MyTable SET Absent='False' WHERE ISNULL(Absent) OR Absent=''; UPDATE MyTable SET clickIn='False' WHERE ISNULL(clickIn) OR clickIn=''; UPDATE MyTable SET clickOut='False' WHERE ISNULL(clickOut) OR clickOut='';

Israel · Answer

Then an idea cames to me. I do try to do this for updating multiple values (for example 3). But doesnt works. How can I resolv that: I try this: UPDATE MyTable SET Absent ='False' and clickIn ='False' and clickOut ='False' WHERE ISNULL( Absent  ClickIn  ClickOut ) OR Absent ='' OR ClickIn ='' OR ClickOut ;

Israel · Answer

@Vulpes Your explanation are always welcome and I do learn all these codes as in a book. Its works nice. Thanx!