parse currency formated number to float in mysql

I have a column in mysql of float type, I need to load curr开发者_Python百科ency like numbers($300) into this column, how do I do that in MYSQL? (let's not argue about the choice of float for this column)

• create temporary table with varchar2 instead of float
• load file in temporary table

• copy data from temporary table to real table and use msql functions to convert the currency into a float, using something like:

  (CAST ( SUBSTRING( TRIM( amountStr ), 1 ) AS FLOAT )