www lonely wives dating club - Mysql updating multiple rows
In this article I’ll give an overview of each feature, help you understand how to choose among them, and point out some things to watch out for. I assume My ISAM tables without support for transactions, with the following sample data: create table t1 ( a int not null primary key, b int not null, c int not null ) type=My ISAM; create table t2 ( d int not null primary key, e int not null, f int not null ) type=My ISAM; insert into t1 (a, b, c) values (1, 2, 3), (2, 4, 6), (3, 6, 9); insert into t2 (d, e, f) values (1, 1, 1), (4, 4, 4), (5, 5, 5);.
In My SQL, when we're doing bulk updates of this kind, we use INSERT ...
ON DUPLICATE KEY UPDATE (with the syntax to keep existing columns intact, as discussed at the link): .
My conclusion is that that the query runs as if there were two different queries running over the bunch of rows resulted after evaluating the WHERE condition, the second CASE operator applying over the data modified by the first CASE operator: 1.
WHERE condition is evaluated; resulted data set: idnode idnode_parent position 3 1 1 4 1 2 9 7 1 2.
For instance in our example when we don't have such values in database, after this query we will have row with article_id = 12 and views_count = 1 (not 2).