So, with the syntax shown earlier in mind, let us put things together, and look at some practical examples.
BTW – If you are interested in where I get the data for these examples – they are from the sample schemas (OE, HR, etc.) that comes with most Oracle database installations.
Should any right be infringed, it is totally unintentional.
Drop me an email and I will promptly and gladly rectify it.
Hi Tom, Due to migration to new system we have to change all our account numbers. June 28, 2005 - pm UTC yes, the predicate in the join for the fictional question without a sample table and data was wrong (everytime I wing it, try to answer WITHOUT TESTING, it comes out wrong. test cases are relevant :) Hi Tom, Thanks for answering my question.
( Client number is consist of branch, Number, Sub Number Currency Code ) We have one big transaction table around 1 million records, having many columns, and at many places client numbers are stored from account master under various columns 1. You told me to use update ( select old.old_account_number, new.new_account_number from old_table old, mapping_table new where old.old_account_number = new.old_account_number ) set old_account_number = new_account_number; But I think my questions still reamin unanswered 1. In your answer only one number say client number will get updated.
In this article, we are going to look at four scenarios for Oracle cross table update. Category_ID) where exists ( select * from Categories b where b. These columns uniquely identify a record in a table.
Suppose we have two tables Categories and Categories_Test. The common column in the two tables is CATEGORY_ID. Please note that query below is used for illustration purpose because Category_ID alone is primary key.
An UPDATE in the cursor loop will update 1 row and 19 columns at once.
But, you might have to have your DBA activate the schemas, and give you access.
Let us start simple, and pretend that the department with id # 20, “Marketing” is from now on going to be named “Customer Relations”.
Cross table update (also known as correlated update, or multiple table update) in Oracle uses non-standard SQL syntax format (non ANSI standard) to update rows in another table. Update data in table A based on two or more common columns in table B.
The differences in syntax are quite dramatic compared to other database systems like MS SQL Server or My SQL. Updates based on two or more common columns are normally used for tables where multiple columns work together as a primary key (known as composite primary key).