Dynamic cursor in mysql

The statement for a cursor is checked at cursor creation time, so the statement cannot be dynamic. The first is for cases where absolutely only one user at a time will be running the procedure. Cursor with Dynamic SQL Query. How To have Dynamic SQL in MySQL Stored Procedure.

Using a cursor with dynamic SQL in a. Creating cursor with Dynamic.

Well-supported dynamic cursors have four characteristics: 1. Metadata about the number of columns and their data types. What if my cursor select query itself is dynamic ? Does MySql support this functionality? First of all thanks to Anonymous friend to ask a question.

Yes it can support, its a little bit tricky. Unlike static cursors, all the changes made in the Dynamic cursor will reflect the Original data. If the dynamic SQL statement represents a SELECT statement that returns multiple rows, you can process it with native dynamic SQL as follows: Use an OPEN-FOR statement to associate a cursor variable with the dynamic SQL statement.

To handle a result set inside a stored procedure, you use a cursor. A cursor allows you to iterate a set of rows returned by a query and process each row individually. MySQL cursor is read-only, non-scrollable and asensitive. Open cursor with a dynamic select statement: 25. I need to make a cursor that can be changed depending on the parameters of the procedure.

Read-only: you cannot update data in the underlying table through the cursor. I have a procedure CREATE PROCEDURE updateTable(IN variable INT) I need the statement for the cursor to include that variable. The tablename in the cursor cannot be dynamic.

In the full proc below where tablename is a variable. FOR dynamic -string Specifies a string literal or string variable that contains a SELECT statement (without the terminating semicolon). Im trying to declare a cursor that i can define only during the runtime. Do I have to deal with dynamic cursors? Is it possible to FETCH a record at a time from a Dynamic (Prepared) cursor ? A prepare statement can be used to create a view with the dynamic SQL and the cursor can select from this statically-named view.

In some applications, having hard coded SQL statements is not appealing because of the dynamic nature of the queries being issued against the database server. Because of this sometimes there is a need to dynamically create a SQL statement on the fly and then run that command. DYNAMIC Defines a cursor that reflects all data changes made to the rows in its result set as you scroll around the cursor and fetch a new recor regardless of whether the changes occur from inside the cursor or by other users outside the cursor.

The expression is evaluate cast to a string, and then parsed as an SQL statement and executed.

MySQL supports cursors inside stored programs. SQL really sucks at looping, and a cursor does exactly that which sucks. My opinion is that you would be better off just getting the data and not locking down your database server while this cursor is working to rearrange how the data is displayed to pivot it. Mysql configuration and Different between and Hot topics of MySQL and More.

The insensitive cursor is used in the same scenarios as the STATIC cursor and is useful in certain cases. Like all cursors, they should only be used when a non- cursor option isn’t available.