Are you expecting this to be your final data? End Date of first occurence shud be one date before 2nd occurence and a default value for the last occurence. Sql Server Now, I am declaring cursor for table, in a row by row fetch I am inserting a data that qualifies the select statement while declaring cursor. For e. Thank you Scott C. I ended up copying all columns from the table and creating a macro to do similarly to what you recommended.
It did the job pretty well. If it is, how. Delete everything after the last column definition indexes, constraints, triggers, permissions, etc. Delete the trailing comma, if any, on the last line.
Use Replace All with Regular Expressions to turn the column definitions into variable declarations. Fix any variable names that still have square brackets. Turn the column names in the FETCH line into variables: replace " " a single space with " " "Use regular expressions" can be turned off. Repeat any manual fixes made above to screwy column names. It's a pretty simple process, although the description may look somewhat wordy.
Thank you both Tim and Jeremy. But if I have to use variables then I'm not sure if you've received my post as I don't see it above. Here it is again and I appologize if I've posted it twice. I have to write a process that reads Employee records, update other tables and insert into another table for other processes. Before updates and inserts can be done, I'd have to do a lot of data manipulations. I guess my question should be:.
When I want to reference a column, I qualify the column name with the cursor name i. But i want to understand the concept of cursor with a simple and easy example WHY do you need a cursor, Deepak? What post processing do you need to do on the data that can't be done using a SET operation? To take a step back, what are you ultimately trying to do?
ETL process? Data import or export? If I understand your first question correctly, you would need to reference each column when you create a variable, populate the cursor, iterate the row set if you are processing each column in some sort of manner. Thank you Tim and Jeremy for your responses. The code I submitted was only an example.
Valid expressions are constants, constant expressions, and in some contexts variables. Column names are not permitted. You should be able to reference the column by name. Did you get an error when you attempted to execute the code above? My first inclination would be that the query you use to populate the cursor is not getting the correct data.
We are using a script very similar to this. It uses exec msdb. A sql view has been written that calls the data set correctly. Some clients have two appts the same day for different reasons and at different times.
Most emails are sent correctly, with the correct data. But these records for clients that have two appts are sending only the data for one of the appts, and then sending it twice. Any ideas? Is there a flush command that can solve this? Ahhhh, yes. Good one, Tim. I think another point to mention is to limit the amount of information obtained for use with the cursor. I see a number of people who select everything from a table even though they only need two fields.
One thing that should be added It runs through the resultset sequentially. Related Articles. Run same command on all SQL Server databases without cursors. Iterate through SQL Server database objects without cursors. Delete duplicate rows with no primary key on a SQL Server table. Rolling up multiple rows into a single row and column for SQL Server data. Popular Articles.
How to tell what SQL Server versions you are running. Resolving could not open a connection to SQL Server errors. In other words, cursors conceptually return a result set based on tables within the databases. The cursor is so named because it indicates the current position in the result set, just as the cursor on a computer screen indicates current position. It is important to become familiar with the concept of cursors before moving on to learn the specifics of their usage in ADO.
For example, consider an application that displays a list of available products to a potential buyer. The buyer scrolls through the list to see product details and cost, and finally selects a product for purchase. Additional scrolling and selection occurs for the remainder of the list.
As far as the buyer is concerned, the products appear one at a time, but the application uses a scrollable cursor to browse up and down through the result set. Sensitive to underlying table changes caused by other applications such as membership, sort, inserts, updates, and deletes. Complex cursors can be defined with keysets that point back to base table rows.
Although some cursors are read-only in a forward direction, others can move back and forth and provide a dynamic refresh of the result set based on changes that other applications are making to the database. Not all applications need to use cursors to access or update data. Some queries simply do not require direct row updating by using a cursor.
Cursors should be one of the last techniques you choose to retrieve data-and then you should choose the lowest impact cursor possible. When you create a result set by using a stored procedure, the result set is not updateable using cursor edit or update methods. Types of Cursors Cursors are classified depending on the circumstances in which they are opened.
Skip to content. Change Language. Related Articles. Table of Contents. Save Article. Here we have some gotchas. Basically, no updates, deletes or inserts made after the cursor was open will be visible in the cursors result set unless we close and reopen the cursor. Be aware of this before using these arguments and check if it matches your needs. Below we have the results:. But there are cases when a dynamic plan is worse than a static one. Although we got the result in an average of 12 seconds using both of this methods, these arguments should be properly tested before choosing one of them.
There are many ways of obtaining the same result, much quicker and with less impact on performance. After hitting the EXECUTE button, we produced the same results in ms, compared to time from the cursor method, and we have a smile on our face.
We do not need to iterate through every row to get what we need, we have no more loops, no while clause, no iterations, we are working with sets of data instead, getting what we want faster and writing less code. This is one method where CURSOR is helpful by iterating through some data one row at a time and gets the result needed.
In this particular case, the cursor gets the job done without having implications on performance and is easy to use.
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