--Declare a cursor
DECLARE MyCursor CURSOR
FOR SELECT TOP 5 FBookName, FBookCoding FROM TBookInfo / / define a cursor called MyCursor, store the data for the select
--Open a cursor
OPEN MyCursor / / open this data set
-- loop a cursor
DECLARE @BookName nvarchar(2000), @BookCoding nvarchar(2000)
FETCH NEXT FROM MyCursor INTO @BookName, @BookCoding//Moving cursor points to the first piece of data, extracting the first piece of data stored in the variable
WHILE @@FETCH_STATUS =0//Continue to cycle if the last operation was successful
BEGIN
Print 'name'+@BookName
FETCH NEXT FROM MyCursor INTO @BookName, @BookCoding//Continue to draw a line
END
--Close the cursor
CLOSE MyCursor
-- Release resources
DEALLOCATE MyCursor
Code:
Create table #a
(
Id varchar(20),
Name varchar(20)
)
Insert into #a select 1, 'jack'
Insert into #a select 2,'join'
Insert into #a select 3,'make'
Declare mycursor cursor
For select * from #a
Open mycursor
Declare @id varchar(20),@name varchar(20)
Fetch next from mycursor into @id,@name
While @@fetch_status=0
Begin
Select @id,@name
Fetch next from mycursor into @id,@name
End
Close mycursor
Deallocate mycursor
Cursors belong to the row-level operation. The SQL query is based on the data set. Therefore, the general query can use the data set. The data set is used. The cursor data is large and the performance killer.
IGBT Module
High short circuit capability, self limiting short circuit current
IGBT CHIP(Trench+ Field Stop technology)
VCE(sat) with positive temperature coefficient
Fast switching and short tail current, Low switching losses
Free wheeling diodes with fast and soft reverse recovery
Temperature sense included
IGBT Module
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