update two table

Problem Description:Two Tables A and B, each with a field, update time A.MODIFIED_TM and B.modified_tm,a table as the main table, update time is not empty, but the B table update time may be empty, now to take a, B two table time the newest one,

Original: Oracle\ms SQL Server Update Multiple Table association updateA single update UPDATE statement is not able to update multiple tables unless you use triggers to suppress updates. In the update operation of the table, in many cases, you need

From: http://blog.163.com/gaofx_hk/blog/static/193999289201172893813254/ Oracle does not have the update from syntax. There are two implementation methods:1. subquery:UpdateSet field 1 = (select field expression from B where ...),Field 2 = (select

PHP implements two methods to update the data in the intermediate joined table: php. PHP implements two methods for updating intermediate joined table data. php provides two methods. This document provides an example to demonstrate two methods for

SQLmdash; mdash; update between two tables: update the fields of the other table with the fields of one table SQLmdash; mdash; update between two tables: update the fields of the other table with the fields of one table -- 1. This statement

Database Learning (4) -- create and update a data table 1 Database Learning (3) -- create and delete a database http://www.bkjia.com/database/201305/207489.html data table is a level object for operations in a relational database. In relational

In order to better optimize MySQL in high concurrency, it is necessary to understand the locking table mechanism when MySQL query is updated.I. OverviewMySQL has three levels of Lock: page level, table level, row level.MyISAM and MemoryStorageThe

Author: Li Jia Source: CSDN development expert Editor: Fangzhou There are two ways to update an application: one is to notify the user (such as sending an email) and let the user download the updated program from the specified website

Http://www.cnblogs.com/quanweiru/archive/2012/11/09/2762223.html 1,for update and for update nowait differences: First of all, if only Select,Oracle will not add any lock, that is, Oracle to Select read the data there is no limit, although it is

1. The difference between for update and for update nowait:First of all, if only select, Oracle will not add any lock, that is, Oracle to select read the data there is no limit, although it is possible that another process is modifying the data in