What should I do if the UpData function of the database in VC prompts that the update fails? Which help

继续跟随教主

m_pSCSet-> Requery ();
while (! m_pSCSet-> IsEOF ())
{
if ((m_pSCSet-> m_grade <= 69)&&(m_pSCSet-> m_grade> = 60))
{
m_pSCSet-> m_grade + = 5;
m_pSCSet-> Update ();
m_pSCSet-> MoveNext ();
}
}
The title is to find tuples with scores between 60 and 69 in the table, and add 5 points to the score, but I use the above code to indicate that the update attempt failed

autice

Write directly with sql statement

dream88

See what type of cursor of the recordset you opened, static cursors and read-only locks cannot be updated
If it's just an update, the first floor method is recommended

xx521xx

[Quote=Quote the post of the original poster继续跟随教主:]
m_pSCSet-> Requery();
while(!m_pSCSet-> IsEOF())
{
if((m_pSCSet-> m_grade <=69)&&(m_pSCSet-> m_grade> =60))
{
m_pSCSet-> m_grade += 5;
m_pSCSet-> Update();
m_pSCSet-> MoveNext();
}
}
The problem is to find the tuples in the table whose score is between 60 and 69, and add 5 points to the score, but I use the above code to indicate that the update attempt failed
[/Quote]

Use SQL directly

update tb
set fenshu = fenshu + 5
where fenshu between 60 and 69

It can also be like this.
declare @sql as varchar(100)
set @sql ='update tb set fenshu = fenshu + 5 where fenshu between 60 and 69'
exec(@sql)

You can put this SQL statement into your vc variable and execute it dynamically.
However, VC should not use exec, but use his own things.

jielun1

1. As required by your code.. only need to update with SQl
2. Pay attention to the cursor of Ado.Recordset you opened to see if it is read-only

jielun1

CursorType cursor type
LockType Lock type

In addition, if you really need to make batch SQL updates in the program, you can use the open batch update mode... but it is not necessary as the title requires, it is too wasteful