Updating joined tables in sql server
This can be done similarily : SET @pos=0; UPDATE busstops SET pos = ( SELECT @pos := @pos 1 ) WHERE route = 1 ORDER BY pos ASCChris H (chansel0049) I experienced a weird issue converting from 4 to 5.
A is a normal table, B is a temporary table: Worked in 4update A, B set A.population=B.pop_count where A.id=In version 5, however, the above query only updated one element while still matching "all"In 5 I had to do it like this:update A RIGHT JOIN B on A.id=set A.population=B.pop_count Updates all population counts correctly.[edit: RIGHT JOIN not LEFT JOIN...] Related to the post of Mohamed Hossam on May 9 2005 am A more general method to updtate more one row: UPDATE table SET f1='foo', f2= IF(f3=value,‘one’, IF(f3=value_bis,’two’,f2)) WHERE f5='afected' This set the values of field 'f2' according to the values of field 'f3' in the rows field f5 'afected'.
You could then do select @value;in order to see what the value was before you updated it My SQL uses Watcom (Oracle) syntax for UPDATE, so it's possible to write something like:update Table1 t1 join Table2 t2 on t1. When done, you "clear" the semaphore by UPDATE table SET value = 0 WHERE name = 'name' The assumption is that the UPDATE is "atomic" in that no concurrent access by another process can occur between testing and setting the value field.
[I have posted this in the Flow Control Functions page last year but I still see people asking how to update multiple rows.
This option takes a list of one or more partitions or subpartitions (or both).
when a row of a subset is lost/deleted/moved away from it, the whole subset will need to be reordered.If you set a column to the value it currently has, My SQL notices this and does not update it. Records not matching the equijoin from table2 are marked with null.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. This facilitates to update table1 column with expression whose corresponding value from table2 is returned as NULL It took me a few minutes to figure this out, but the syntax for UPDATING ONE TABLE ONLY using a relationship between two tables in My SQL 4.0 is actually quite simple:update t1, t2 set t1.field = t2.value where t1= t2.that; It should be noted that even simple applications of UPDATE can conflict with the 'safe mode' setting of the mysql daemon.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 '