Mysql declare cursor with variable

Cursor declarations must appear before handler declarations and after variable and condition declarations. A stored program may contain multiple cursor declarations, but each cursor declared in a given block must have a unique name. For an example, see Section 13.

Below is a function that uses this cursor. Use variable when declaring cursor. MySQL Cursor with a variable in select. How to declare a variable in MySQL? Declare a user-defined variable 2. Let’s start with looking at all of them one by one.

There are primarily three types of variables in MySQL. And each has its specific way to provide a declaration. The finished is a variable to indicate that the cursor has reached the end of the result set. Notice that the handler declaration must appear after variable and cursor declaration inside the stored procedures. The variable can be referred to in blocks nested within the declaring block, except those blocks that declare a variable with the same name.

For examples of variable declarations, see Section 13. Local Variable Scope and Resolution”. Using cursors involves several distinct steps: Before a cursor can be used it must be declared (defined).

DECLARE curCURSOR FOR SELECT i FROM test. Otherwise, a local variable is NULL. The operations are made after the declarations, by aknowledging the existing, declared local variables. Following are the steps for creating a cursor.

A cursor is a select statement, defined in the declaration section in MySQL. To use a SQL cursor , you first must declare its existence to the DBMS. The datatype to assign to the variable. It is the value initially assigned to the variable when it is declared. DEFAULT initial_value Optional.

Mysql stored procedure using cursor fetched variable in sql query. If you refer to a variable that has not been initialize it has a value of NULL and a type of string. A cursor variable name - A variable name pointing to a cursor object. To declare a cursor variable , you use the REF CURSOR is the data type. The following shows an example of a strong REF CURSOR.

Here is a more simplified test case. I need to use a variable to indicate what database to query in the declaration of a cursor. However, declaring variables with the same name in different scopes is not good programming practice.

Because a variable is only effective in its scope. It is available and accessible until the session ends. Sidenote : Where are weekly_com and monthly_com coming from ? I have read the documentation and I still need help with the same problem.

The PHPadmin hides the DELIMITER from the user when running a script so I used TOAD.