SQL Server

Before just read about the addition of the percent feature in SQL Server 2008, today finally has the opportunity to try!The data processed today, the top let the change, the marketing result of the value of NULL 20% instead of "failed", 80% to

Connection QueryIt is important to note that the table name must be added before the field to confuse1 -- Multi-table join queries and subqueries 2 Select * from Dbo.stu_info, Dbo.sname2 3 -- query where the join rule is added 4 Select * from

But we can solve this problem in another way. Next we will analyze the solution. String operations cannot be performed on text or ntext data in queries. In this case, the most commonly used method is to treat text as varchar (when the actual content

When 2005 is enabled, the following error occurs: Failed to Load file or assembly "System. Data, Version = 2.0.0.0, Culture = neutral, PublicKeyToken = b77a5c561934e089" or one of its dependencies. The system cannot find the specified file.

Copy codeThe Code is as follows:-- Begin distributed transaction [transactionname]-- Mark a TSQL Distributed Transaction managed by the Distributed Transaction Processing Coordinator MSDTC.-- Server a is the master SERVER. When the connection sends

The procedure is as follows:① Automatically numbered field in AccessRight-click your table --> design table --> Find your id field (int type) --> id --> yes --> id seed (initial value) --> incremental id --> OK② Use the IDENTITY (SEED, INCREMENT)

I. Overview of Indexes 1. Concept: a database index is a structure that sorts the values of one or more columns in a data table, just like a directory in a book, indexes provide the ability to quickly query specific rows in rows. 2. Advantages

Since MS SQL Server 2005, Microsoft has introduced batch and unbatch to implement row-and-column conversion, which greatly facilitates data storage and presentation. Today, we will analyze these two keywords and explain how to store and present data

Cursors are evil! In relational databases, we think about queries in a set. The cursor breaks this rule and changes the way we think about it into a row-by-row approach. For C-like developers, this approach is more comfortable. The normal way of

In SQL Server, you can call the command line tool bcp under DOS to generate text files for the data or SQL statement results in the table.BCP command parameter format:Copy codeThe Code is as follows:BCP {dbtable | query} {in | out | queryout |

The with rollup operator is useful when generating reports that contain subtotal and aggregate. The result set generated by the ROLLUP operator is similar to the result set generated by the CUBE operator.Copy codeThe Code is as follows:SELECT

There are two ways to get the execution plan:1. One is to enable some switches in front of the command to put the execution plan information in the result set. This method is suitable for tuning a single statement in a test environment.These

The following code has passed the test on the sample database of SQLServer2008Question 1: How to encrypt and decrypt data to prevent users from stealing confidential data? Some sensitive data, such as passwords and card numbers, cannot be stored

Let's take a look at the paging SQL of a single SQL statement.Method 1:Applicable to SQL Server 2000/2005Copy codeThe Code is as follows:Select top page size *FROM table1WHERE id NOT IN(Select top page size * (page-1) id FROM table1 order by

The Code is as follows: The structure of the landundertake table is as follows: The structure of the table appraiser is as follows: Access code:Copy codeThe Code is as follows:TRANSFORM First (Landundertake. valuerId) AS valuerId FirstSELECT

(5) SELECT (5-2) DISTINCT (5-3) TOP () (5-1) (1) FROM (1-J) JOIN on (2) WHERE (3) group by (4) HAVING (6) order by ; A virtual table is generated for each step, which is used as the input for the next step. These virtual tables are not

I. Clustered IndexThe page level of the clustered index includes the index key and data page. Therefore, the answer to what the leaf level of the clustered index stores besides the key value is everything, that is, all fields in each row are in the

SQL UNION operator The UNION operator is used to merge the result sets of two or more SELECT statements. Note that the SELECT statement inside the UNION must haveSame quantity. Columns must also haveSimilar data types. In additionSequenceMust be the

In practical applications, when we want to hand over a project to the customer, we need to clear all the previous test data of all tables in the database to give the customer a clean database, if there are many tables involved, it takes not only

These packages can be used independently or together with other packages to meet complex business needs. Integration Services can extract and convert data from multiple origins (such as XML data files, flat files, and relational data sources) and