How Can I Dynamically Iterate Through MySQL Column Names Using a Stored Procedure?

Dynamically Iterating Through Column Names in a MySQL Table

This question explores a method for iterating through column names in a MySQL table using a stored procedure written in native SQL. The goal is to obtain a list of column names and then execute a stored procedure based on each column name as a variable.

Retrieving Column Names

To retrieve column names from a MySQL table, use the SHOW COLUMNS FROM command. This command returns a result set containing information about the table's columns, including their names.

Looping Through Column Names

Once the column names are retrieved, they can be stored in a loop using a cursor. A cursor is an iterator that enables traversing a result set row by row. Here's an example:

DECLARE col_names CURSOR FOR
  SELECT column_name
  FROM INFORMATION_SCHEMA.COLUMNS
  WHERE table_name = 'tbl_name'
  ORDER BY ordinal_position;

This cursor selects the column names from the specified table, orders them by their position, and names the cursor col_names.

Executing a Loop

To iterate through the column names and execute a stored procedure, use the following loop:

SET i = 1;
the_loop: LOOP

  IF i > num_rows THEN
    CLOSE col_names;
    LEAVE the_loop;
  END IF;

  FETCH col_names 
  INTO col_name;     

   //do whatever else you need to do with the col name

  SET i = i + 1;  
END LOOP the_loop;

This loop uses a FETCH statement to retrieve the next column name into a variable col_name. Inside the loop, any necessary actions based on the column name can be performed.

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