MySql How to set a local variable in an update statement (Syntax?)

Question

How can I set a variable while doing an Update statement? I can\'t seem to figure out the syntax.

So I want something like this below but it\'s saying the syntax is

Answer 1

If you want to obtain something like this:

SET @tempVariable := 0; UPDATE myTable SET col1 = 5, col2 = @tempVariable, @tempVariable := 100;

You can do a trick like this:

• Create a column value.

ALTER TABLE Proj ADD col3 numeric;

• Give a value to col3 in order to set the variable you need (@tempVariable).

SET @tempVariable := 0; UPDATE myTable SET col1 = 5, col2 = @tempVariable, col3 = @tempVariable := 100;

• Drop the col3

ALTER TABLE Proj DROP col3;

In this way, you can assign values to a variable without change attributes of a table. It is really usefull when setting dinamic values.

FOR EXAMPLE: @tempVariable := @otherVariable + 100;