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Tags: sel example condition end statistics from ASE and stylethe If-else statement in//sqlIF (condition)BEGINStatement 1Statement 2... ...ENDELSEBEGINStatement 1Statement 2... ...END Example:IF (@score > 85)PRINT ' Exam level: ' + ' excellent 'ELSE IF (@score > 70)PRINT ' Exam level: ' + ' good 'ELSE IF (@score > 60)PRINT ' Exam level: ' + ' Medium 'ELSEPRINT ' Exam level: ' + ' difference ' The while statement in SQLwhile (condition)BEGINStatement 1Statement 2......BreakEND Example:DECLARE @n
As mentioned earlier, the database server consists of two parts: instance and database.Where the database is used to store data, and the instance is used to access the data in the database.The instance includes a set of memory structures and background processes, and the structure of the database needs to be understood from two aspects of
1. OverviewThe Ldb_process function allows any program to access the logical database, allow one program to access multiple logical databases, and, of course, allow multiple successive accesses to the same logical database. When using the Ldb_process function to access the
The first thing you need to do is database files, and the binary log files are all placed in separate logical volume storage. Implement LVM logical volumes, data, binary log files to separate and store one, create logical volume step (1), create new partition1, check the zoning and see how much space is left. [[emai
What is the logical file name? The program you use is connected with the database name, and then you right-click the property in your database, click "File" in the upper left corner, you can see that the database name and logical file name is not the same, you can look at t
First, IntroductionA logical backup is the process of exporting the structure and data of a data object to a file using the tools export.Logical recovery refers to the process of importing a data object into a database using a backup file when the database object is damaged by mistake.Physical backups can be performed in the open state of the
First, IntroductionA logical backup is the process of exporting the structure and data of a data object to a file using the tools export.Logical recovery refers to the process of importing a data object into a database using a backup file when the database object is damaged by mistake.Physical backups can be performed in the open state of the
Tags: SP file data div Log BS nbsp database sqlThe original database name is AA, the physical file name is called Aa.mdf and aa_log.ldf; you need to modify the database name to BB, the physical file name is called Bb.mdf and Bb_log.ldf; procedure (take the sqlserver2005 operation as an example): Prepare the original database
Oracle databases have two types of backup methods. The first class is a physical backup, this method realizes the complete recovery of the database, but the database must run in the return mode (the business database runs in the non-return mode), and it needs a great external storage device, such as a tape library; the second type of backup is a
Requirements for the character set (collation) on the destination database when implementing the logical replication software1. When the destination database is an Oracle database, it is important to ensure that the character set of the destination Oracle database is consist
, contact person, contact phone, address and other attributes; "Product" Information basically includes: name, type, specifications, unit price and other attributes; "Order" information basically includes: Date and time attributes. and "order" to the "customer", "salesman" and "product" details are associated. The system needs to establish several data tables: Salesman information table, Customer Information table, Commodity information table, order form. The system should include several functi
Today the Sql-server database suddenly complains: SQL Server has detected a consistent, logical I/O error checksum (should be: 0x7c781313, but actually: 0X67A313C9). In the file ' C:\Program Files\Microsoft SQL Server\mssql.1\mssql\data\e_block_db.mdf ', the offset is 0x00000000a34000 to the page in database ID 5 (1 : 1306 This error occurred during read executi
Tags: Oracle-------------------------------Logical Structure------------------------------------ Reference Document: Chapter 12 Tablespace table Space Maximum storage unit Establishment object specifies that the table space is stored Segment segment: Can store data table segment (set up table XS must suggest segment XS) Extent Area: Space allocation unit (at least one area of the object) Oracle data Block database
undo_management=manual scope=spfile; The instance will not take effect until you launch itUser-created rollback segments require that the rollback segment be set to manual to modify:To view how table space segments are managed:SELECT tablespace_name,segment_space_management from Dba_tablespaces;To create a rollback segment:CREATE ROLLBACK SEGMENT ORCLRS01 tablespace RSC STORAGE (inital 5M NEXT 2M MAXEXTENTS UNLIMITED)To modify the state of a rollback segment:ALTER ROLLBACK SEGMENT ALTER ROLLBAC
Tags: blog http ar os using SP data log CodeA more stable Biz class Library, which is integrated from the next few and fixes bugs. Open source Code, C # version. You can download it directly or take a look at the next few steps to learn more about the operation and evolution.The ASP. NET development, from two to three levels to object oriented http://www.cnblogs.com/insus/p/3822624.htmlThe ASP. NET development, from two to three layers to object-oriented (2) "http://www.cnblogs.com/insus/p/38258
(10)) tablespace users;--Create a cluster index for the cluster keyCREATE index Idxclusterclassno on cluster cluster_classno;--Create a cluster table (primary key table, foreign key table)Create a primary key table-class tableCREATE TABLE Classes(Vclassno VARCAHR2 (10),Vclassname VARCHAR2 (20)) cluster Cluster_classno (VCLASSNO);Create a foreign key table-Student tableCREATE TABLE Students(Vstudentno VARCHAR2 (10),Vstudentname varchar2 (20),Vclassno VARCHAR2 (10)) cluster Cluster_classno (VCLAS
Tags: database designDatabase design (i)--Database design IntroductionAccording to the standard design, the database design process is divided into six stages:A, the system requirements
MYSQL database design and database design example (I) preparations before bitsCN.com database design and database design
of multiple fields, telephone numbers and e-mail addresses preferably have their own data tables, with its own type and tag category; (3) using the role entity definition belongs to a class of columns, creating a specific time association relationship, so that you can achieve self-documentation; (4) Select the number type and text type to be as sufficient as possible, otherwise can not be calculated operation; (5) Add the delete tag field. Do not delete a row individually in the relational
Summary: For database design, we generally start from the conceptual model. In the conceptual model design phase, we focus on analyzing the logical structure of data to avoid getting into the specific storage details, all designs are irrelevant to specific database products
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