How to update table values in batches

How to update table values in batches now I have a data table with the field type. There are N pieces of information in the data table. I want to change the type value based on different classid conditions. But now there are multiple types corresponding to multiple sets of conditions. for example, if class = 1, type = rassclass = 8, type = bbcc and multiple groups, how can I update table values in batches?
Now I have a data table with the field type. The data table contains N pieces of information,
I want to change the value of type based on different classid.
But now there are multiple types corresponding to multiple sets of conditions.
For example, when class = 1, type = rass
Class = 8, type = bbcc


There are multiple groups of such cases. how can I update all types one by one at a time.

I can't help myself. I just learned that I can think of the update table set type = corresponding value where class = corresponding value.

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CASE value WHEN [compare_value] THEN result [WHEN [compare_value] THEN result...] [ELSE result] END
Case when [condition] THEN result [WHEN [condition] THEN result...] [ELSE result] END


Http://dev.mysql.com/doc/refman/5.1/en/control-flow-functions.html#operator_case

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Your database does not conform to the third paradigm. we recommend that you break it down: Create (class, type) and remove the type from the original table.
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SQL where queries that meet the conditions, and then updates
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If the ing between your class and type is not regular, do not use if, else, or case when then. Otherwise, how long will it take?

Create a table separately and store the ing between class and type. when updating the table, run the following command with the table: