Updating tables within cursor loop

END block, duplicating the code for the handler and the loop control, or you can reset your loop control variable inside the inner loop once the cursor is exhausted.I won't post an example here, as this would soon clutter the page. A cursor is a set of rows together with a pointer that identifies a current row. Series of Interview questions to brushup your skills In this example we will learn – How to use CURSOR in HANA.PDF (US Ltr) - 37.5Mb PDF (A4) - 37.5Mb PDF (RPM) - 36.9Mb HTML Download (TGZ) - 10.2Mb HTML Download (Zip) - 10.2Mb HTML Download (RPM) - 8.9Mb Man Pages (TGZ) - 211.3Kb Man Pages (Zip) - 321.0Kb Info (Gzip) - 3.4Mb Info (Zip) - 3.4Mb My SQL Backup and Recovery My SQL Globalization My SQL Information Schema My SQL Installation Guide My SQL and Linux/Unix My SQL and OS X My SQL Partitioning My SQL Performance Schema My SQL Replication Using the My SQL Yum Repository My SQL Restrictions and Limitations Security in My SQL My SQL and Solaris Building My SQL from Source Starting and Stopping My SQL My SQL Tutorial My SQL and Windows My SQL NDB Cluster 7.5 CREATE PROCEDURE curdemo() BEGIN DECLARE done INT DEFAULT FALSE; DECLARE a CHAR(16); DECLARE b, c INT; DECLARE cur1 CURSOR FOR SELECT id,data FROM test.t1; DECLARE cur2 CURSOR FOR SELECT i FROM test.t2; DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE; OPEN cur1; OPEN cur2; read_loop: LOOP FETCH cur1 INTO a, b; FETCH cur2 INTO c; IF done THEN LEAVE read_loop; END IF; IF b PDF (US Ltr) - 37.5Mb PDF (A4) - 37.5Mb PDF (RPM) - 36.9Mb HTML Download (TGZ) - 10.2Mb HTML Download (Zip) - 10.2Mb HTML Download (RPM) - 8.9Mb Man Pages (TGZ) - 211.3Kb Man Pages (Zip) - 321.0Kb Info (Gzip) - 3.4Mb Info (Zip) - 3.4Mb My SQL Backup and Recovery My SQL Globalization My SQL Information Schema My SQL Installation Guide My SQL and Linux/Unix My SQL and OS X My SQL Partitioning My SQL Performance Schema My SQL Replication Using the My SQL Yum Repository My SQL Restrictions and Limitations Security in My SQL My SQL and Solaris Building My SQL from Source Starting and Stopping My SQL My SQL Tutorial My SQL and Windows My SQL NDB Cluster 7.5 Hi all, as beat pointed out, LOOP is the only construct that I found useful for traversing cursors. See examples: Nesting cursors is possible, you just need to take care of a few things.You can either put the inner cursor in it's own BEGIN..In a previous Tech Republic column about SQL Server 2005, I showed how you can convert some of your iterative queries (cursors) to set-based operations in order to enhance performance.

updating tables within cursor loop-56updating tables within cursor loop-40updating tables within cursor loop-48updating tables within cursor loop-65

Depending on the type of cursor you request, you can even fetch records that you've previously fetched.What I love about writing SQL Tuning articles is that I very rarely end up publishing the findings I set out to achieve. We have a table containing years worth of data, most of which is static; we are updating selected rows that were recently inserted and are still volatile. For the purposes of the test, we will assume that the target table of the update is arbitrarily large, and we want to avoid things like full-scans and index rebuilds.With this one, I set out to demonstrate the advantages of PARALLEL DML, didn't find what I thought I would, and ended up testing 8 different techniques to find out how they differed. The methods covered include both PL/SQL and SQL approaches.) and set the variable 'done' to true - after the first itteration the loop was acting as if the end of the data was hit.The solution I found is somewhat cumbersome (but works!The cursor provides the functionality to iterate through a query result row-by-row. Note: Avoid using cursors when it is possible to express the same logic with SQL.

You must have an account to comment. Please register or login here!