Updating a table in sql
Typically, this is done by executing a stored procedure or batch that contains individual INSERT, UPDATE, and DELETE statements.
However, this means that the data in both the source and target tables are evaluated and processed multiple times; at least once for each statement.
In SQL Server 2008, you can perform multiple data manipulation language (DML) operations in a single statement by using the MERGE statement.
For example, you may need to synchronize two tables by inserting, updating, or deleting rows in one table based on differences found in the other table.
The users cannot see the indexes, they are just used to speed up searches/queries.
Note: Updating a table with indexes takes more time than updating a table without (because the indexes also need an update).
This problem can solved in multiple ways, below are two such example approaches.
This chapter explains how to create and use PL/SQL collection and record variables.
These composite variables have internal components that you can treat as individual variables.
The SQL CREATE TABLE statement is used to create a new table.
The basic syntax of the CREATE TABLE statement is as follows − CREATE TABLE is the keyword telling the database system what you want to do. The unique name or identifier for the table follows the CREATE TABLE statement.