Second, the SET clause specifies which column that you want to modify and the new values.
UPDATE tbl_name SET fld2 = CASE fld1WHEN val1 THEN data1WHEN val2 THEN data2ELSE fld2 ENDThe note is: do not forget ELSE.If you do not use it, all rows that are outside the range of your updated values will be set to blank!Here is generic SQL syntax of UPDATE command to modify data into My SQL table: The WHERE clause is very useful when you want to update selected rows in a table.This will use SQL UPDATE command with WHERE clause to update selected data into My SQL table tutorials_tbl.If you set a column to the value it currently has, My SQL notices this and does not update it.
If you update a column that has been declared , an error occurs if strict SQL mode is enabled; otherwise, the column is set to the implicit default value for the column data type and the warning count is incremented.
So, I do it in one "magick" query ;)Here an example:"3" is a some value, from form or somethingupdate item set rate = case when round((rate 3)/2) You sometimes run into the problem that you want to replace a substring occuring in a column with a different string, without touching the rest of the string.
The solution is surprisingly simple, thanks to My SQL: UPDATE xoops_bb_posts_text SET post_text=( REPLACE (post_text, 'morphix.sourceforge.net', ' the string function REPLACE, all items in the post_text column with 'morphix.sourceforge.net' get this substring replaced by '
[I have posted this in the Flow Control Functions page last year but I still see people asking how to update multiple rows.
So, here it is again.]A very server resources friendly method to update multiple rows in the same table is by using WHEN THEN (with a very important note).
Ideal when writing a script is just too much effort.