cursor

Understanding the cursor (2) Introduction to the attribute of the cursor and Case Study of Different cursor categories links: Understanding the cursor (1): Overview of the cursor http://www.bkjia.com/database/201212/177395.html PL/SQL provides six

Learning MongoDB 6: MongoDB query (cursor operation, cursor information) (3), mongodb cursorI. Introduction Db. collection. find () can be used to query based on conditions and specify fields returned using the projection operator to omit this

The PL/SQL cursor provides a way for a program to select multiple rows of data from a database and then handle each row separately, providing Oracle with a means to indicate and control the stages of SQL processing. I will think you have a certain

http://blog.csdn.net/gyflyx/article/details/6889028Reference one, explicit cursorExplicit is relative to the implicit cursor, which is the cursor with a clear declaration. The declaration of an explicit cursor is similar to the following (the

During database development, when you retrieve data that is only a single record, the transaction statement code that you write tends to use the Select INSERT statement. But we often encounter situations where one record is read from one result set

One: Understanding CursorsCursor It enables the user to access the result set returned by SQL Server on a row-by-line basis.One of the main reasons for using cursors is to convert the set operation to a single record processing mode.When data is

I. Classification of Cursors The Oracle database provides two types of cursors, static and dynamic, while static cursors are divided into hermit cursors and explicit cursors, and dynamic cursors are classified as weak and strongly typed. Second,

Download an English attachment: Cursor in ArcObject Chinese Translation: Cursor in ArcObject This article is an article in the first installment of ArcUser 2006, introducingThe Cursor object in Arcobjects introduces how foreigners know Cursor.. The

1. What is the cursor? Oracle uses two types of cursor: explicit cursor and implicit cursor. No matter how many records are returned by the statement, PL/SQL implicitly declares a cursor for each SQL command, such as UPDATE, DELETE, and INSERT. To

There are two types of cursors: Display cursor, implicit cursor   Cursor is used to display the cursor... the is command defines the cursor, which can process multiple records returned by the query statement (select), while the implicit cursor is

SQL Server supports three types of cursors: Client cursor API server cursor T-SQL cursor The main difference between T-SQL cursors and other types of cursors is that they are used differently.The T-SQL used in a stored procedure, batch, function,

An Oracle cursor is divided into a display cursor and an implicit cursor. Display cursor (Explicit Cursor): A cursor defined in a PL/SQL program, used for querying, is called a display cursor.Implicit cursors (implicit Cursor): A cursor that is

Reference one, explicit cursorExplicit is relative to the implicit cursor, there is a clear statement of the cursor. The declaration of an explicit cursor resembles the following (verbose syntax participates in Plsql ref doc):Cursor cursor_name

1. Why cursors are used: one of the main reasons for using cursors is to convert the set operation into a single record processing mode. When data is retrieved from a database in SQL language, the result is placed in an area of memory, and the

I recently handled some memory leaks in my work. In this process, I found some basic problems, instead of causing memory leaks, such as static variables, cursor shutdown, threads, timer, anti-Registration, bitmap, etc. I have made some statistics

PL/SQL cursor usage Use of cursors ① Cursor ConceptTo process SQL statements, Oracle must allocate a region called context area to process required information,This includes the number of rows to be processed, a pointer to the expression after the

Recently handled some memory leaks in the work, in this process I found some basic problems instead of causing memory leaks, such as static variables, cursor shutdown, thread, timer, reverse registration, bitmap and so on, I have a little statistics

The PL/SQL cursor allows the program to select multiple rows of data from the database, and then separately process each row of data, it provides Oracle with a method to indicate and control each stage of SQL processing. I think you have some

The cursor is evil!In a relational database, our thinking about queries is set-oriented. The cursor breaks this rule, and the cursor makes us think in a progressive way. For developers of Class C, this way of thinking will be more comfortable.The

The cursor mentioned here is of course the transaction-SQL cursor. Any type of cursor will reduce the performance of SQL Server. However, the reason why the cursor exists is that it is still inevitably used in some situations. What we should do is