Updating table rows in php 4
If you want to return the value before you updated it without using a seperate select (which unless you lock the table could return a different value than is updated) then you can use a mysql variable like this:update some_table set col = col 1 where key = 'some_key_value' and @value := col The @value := col will always evaluate to true and will store the col value before the update in the @value variable. Additional information on My SQL correlated subqueries is at UPDATE can apparently be used to implement a semaphore (pardon my pseudocode):while TRUE The code above waits until the semaphore is "cleared" (value = 0) and then "sets" it (value = 1).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.Only the partitions (or subpartitions) listed are checked for matches, and a row that is not in any of these partitions or subpartitions is not updated, whether it satisfies the clause, are flagged as unsafe for statement-based replication.2 | 22 from 01 08 2003 / 23 from 02 08 2003 / | | 3 |
Search for updating table rows in php 4:
PDF (US Ltr) - 37.9Mb PDF (A4) - 37.9Mb PDF (RPM) - 32.9Mb HTML Download (TGZ) - 8.0Mb HTML Download (Zip) - 8.1Mb HTML Download (RPM) - 6.9Mb Man Pages (TGZ) - 132.7Kb Man Pages (Zip) - 189.0Kb Info (Gzip) - 3.4Mb Info (Zip) - 3.4Mb My SQL Backup and Recovery My SQL Globalization My SQL Information Schema My SQL Installation Guide Security in My SQL Starting and Stopping My SQL My SQL and Linux/Unix My SQL and Windows My SQL and OS X Building My SQL from Source My SQL Restrictions and Limitations My SQL Partitioning My SQL Secure Deployment Guide My SQL Tutorial My SQL Performance Schema My SQL Replication Using the My SQL Yum Repository option as part of a table reference.