sql cursor

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,

SQL cursor principle and usage During database development, when the data you retrieve is only one record, the transaction statement code you write usually uses the select insert statement. However, we often encounter this situation, that is,

A MS-SQL cursor is a temporary database object that is used to rotate copies of data rows stored in a system Permanent Table, it can also point to the data row stored in the system Permanent Table. A cursor provides you with a method to operate data

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

During database development, when the data you retrieve is only one record, the transaction statements you writeCodeSelect Insert statements are usually used. However, we often encounter this situation, that is, reading a record from a result set

Cursor and dynamic SQL, cursor dynamic SQL Cursor type: Static cursor (the cursor is statically bound to a select statement during compilation. This cursor can only act on one query statement) and dynamic cursors (that is, we want our query

1. Define the cursor DefinitionThe core of a cursor statement is to define a cursor Identification name and associate it with a query statement. The DECLARE statement is used to DECLARE the cursor. It defines the data set stored in the cursor

PL/SQL language development Reference Manual: PL/SQL cursor PL/SQL language development Reference Manual1. cursor)The cursor is the data extracted from the data table. It is stored in the memory as a temporary table. There is a data pointer in the

Http://www.cnblogs.com/Gavinzhao/archive/2010/07/14/1777644.html1The Table1 structure is as follows2IdInt3Namevarchar(50)45Declare@idInt6Declare@namevarchar(50)7DeclareCursor1CursorFor--Defining Cursors Cursor18Select*FromTable1--Objects using

Code highlighting produced byActipro codehighlighter (freeware) http://Www.CodeHighlighter.com/--> 1 table1 structure as followsIdintnamevarchar( -)Declare @id intDeclare @name varchar( -)DeclareCursor1cursor for --Defining Cursors

PL/SQL cursor usage, plsql cursor usageZookeeper 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

SQL cursor usage (reproduced) I. The cursor consists of two parts:1. The cursor result set is a set of rows returned by the SELECT statement that defines the cursor.2. pointer to a row in the Set Ii. cursor processing process:Declare statement

When an SQL statement is used, the Oracle server allocates a large block of memory to parse and execute SQL commands. This workspace is a cursor. When the execution part of a block contains an SQL statement, PL/SQL creates an implicit cursor and

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

Oracle Database: PL/SQL cursor overview, oracleplI. cursor Concept Literally, it refers to a swimming cursor, which is a handle or pointer pointing to the context area. When performing the CRUD operation in the PL/SQL block, ORACLE allocates a

Requirements: WEBAPI server, access to data through the Oracle database's stored procedures.To establish a stored procedure in PL/sql: (First and foremost, the entire table is detected)Create or Replace procedure is begin Open for ' SELECT * from

What is a cursorThe result set, which is the collection of all row data returned after the select query.Cursors are a mechanism for working with result sets, which can locate a row in the result set, read or write multiple data, or move the cursor

SQL Cursor example filters data from another table based on data from one tableDECLARE @MID nvarchar (20)DECLARE @UTime datetimeDECLARE @TBL_Temp Table(MID nvarchar (20),Uptime datetime,Chat nvarchar (20))--get UserDECLARE my_cursor Cursor--Defining

The table1 structure is as follows2Idint 3Namevarchar( -) 4 5 Declare @id int 6 Declare @name varchar( -) 7 DeclareCursor1cursor for --Defining Cursors Cursor1 8 Select * fromTable1--objects using cursors (fill in select text as required)

1. Cursors are useful when the data table has no ID (identity), but the cursor eats more memory, reduces available concurrency, consumes bandwidth, locks resources, and, of course, more code2. If you can not use cursors, try to avoid using cursors,