Αποτελέσματα Αναζήτησης
If you want to update specific rows (ie where the IDs match) you probably want to do a coordinated subquery. However, since you are using Oracle, it might be easier to create a materialized view for your query table and let Oracle's transaction mechanism handle the details.
6 Δεκ 2017 · There are several different ways to use subqueries in UPDATE statements. Let’s take a look at each of them. SET and Subquery. The first method we will look at is using a subquery in the SET clause of an UPDATE statement. Let’s say we had a table of products that looked like this: [table id=29 /]
Subquery Method. The first option is to do an update of the DEST_TAB table using a subquery to pull the correct data from the SOURCE_TAB table. Notice the EXISTS predicate to exclude rows from the DEST_TAB table with no matching row in the SOURCE_TAB table.
4 Αυγ 2024 · Ever found yourself needing to update a bunch of rows in your database, but the condition for the update depends on data from another table? That’s where UPDATE with a subquery comes in handy. Let’s break it down.
let's say I have select, which return me from table1: ID Name. 1 Bob. 2 Alice. 3 Joe. Then I want UPDATE values in another table based on this result: UPDATE table2 SET Name = table1.Name WHERE ID = table1.ID. As I understood, I can only do internal select in one place, like: UPDATE table2 SET Name = (select Name from table1) WHERE ...
Introduction to the Oracle subquery. A subquery is a SELECT statement nested inside another statement such as SELECT, INSERT, UPDATE, or DELETE. Typically, you can use a subquery anywhere that you use an expression. Consider this following subquery example that uses the products table from the sample database.
An example of using a sub query to update a record is illustrated by the following diagram: UPDATE product_obj_table p1. SET package_id = (SELECT REF(p2) . FROM product_obj_table p2. WHERE product_id = 14) WHERE product_id = 22; The UPDATE statement. SET package_id =SELECT. FROM product_obj_table. WHERE product_id =14. WHERE product_id=22.
