How to iterate properly over cursor in teradata sql?

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by addison , in category: MySQL , a month ago

How to iterate properly over cursor in teradata sql?

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1 answer

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by lew , a month ago

@addison 

To iterate properly over a cursor in Teradata SQL, you can use the following steps:

  1. Open the cursor using the OPEN statement.
  2. Fetch the first row from the cursor using the FETCH statement.
  3. Check if the FETCH statement was successful by checking the SQLSTATE variable. If the FETCH was successful, process the row. If not, close the cursor and exit the loop.
  4. Continue fetching the next row from the cursor in a loop until there are no more rows to fetch.
  5. Close the cursor using the CLOSE statement.


Here is an example of how to iterate over a cursor in Teradata SQL:

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CREATE PROCEDURE iterate_cursor()
BEGIN
    DECLARE cursor_name CURSOR FOR
        SELECT column1, column2
        FROM your_table;
    
    OPEN cursor_name;
    
    FETCH NEXT FROM cursor_name
    INTO @variable1, @variable2;
    
    WHILE SQLSTATE = 'OK' DO
        -- Process the row
        INSERT INTO another_table VALUES (@variable1, @variable2);
        
        FETCH NEXT FROM cursor_name
        INTO @variable1, @variable2;
    END WHILE;
    
    CLOSE cursor_name;
END;


In this example, the cursor fetches rows from your_table and processes each row by inserting it into another_table. The loop continues until all rows have been processed, at which point the cursor is closed.