SQL Server

For example: Select * From Table1 where name = ''zhangsan'' and TID> 10000 And execution: Select * From Table1 where TID> 10000 and name = ''zhangsan'' Some people do not know whether the execution efficiency of the preceding two statements is the

I used to call the Excel component in c # to generate an Excel applet.I called PM a few days ago and asked why the SQL Server memory usage is so high after the run?The Server is configured with 2 GB of memory. After the program is properly executed,

Every time we talk about the high availability of SQL Server, many DBAs, especially SQL Server DBAs, feel a pain: Because we all think that SQL Server cannot or is difficult to implement SQL Server. There are also a lot of DBA friends with a head

SQL statement Copy codeThe Code is as follows: reverse (substring (reverse (Path), 1, charindex ('/', reverse (Path)-1 )) How can I retrieve the right character of the last special character in a string, for example, 10*20*300? How can I get 300?

Many SQL Server programmers are confused about the use of subqueries, especially nested subqueries (that is, subqueries contain a subquery ). Now let's trace this problem. There are two subquery types: standard and related. The standard subquery is

During the implementation of software projects, data import has always been a headache for the project staff. In fact, many data import methods are integrated in SQL Server. Some project implementation consultants have a headache. In the eyes of our

SQL Server 2000Log cleanup tutorial SQL Server 2000 database logs are too large!How can I clean up SQL Server 2000 logs?How to compress SQL Server 2000 logs?How can I reduce the Log Size of SQL Server 2000? As far as xiaobian knows, there are many

Background: when creating a project, we often encounter a table structure that stores a column in the master table separated by commas. For example, when an employee belongs to multiple departments, a project belongs to multiple cities, and a device

1.1.1 Summary Join is one of the important operations of the relational database system. Common Join Operations in SQL Server include internal Join, external Join, and cross Join. If we want to obtain data from two or more tables that matches rows

For example:Select. key, B. key, C. key from A, B, C where trim (. key) = trim (B. fk) and trim (. col) = trim (C. pk ).It takes one second to associate primary Table A (more than 200 records) with Appendix B (more than 40 thousand records). This

Data conversion conflicts and ProcessingData conversion conflict: In the data conversion process, it is difficult to implement strict equivalent conversion. You must determine the syntax and semantic conflicts in the two models. These conflicts may

The method is simple: Replace cannot be used for text fields, so patindex is used.Copy codeThe Code is as follows:-Select * from Product where P_Intro like '% %'-- Example of text field replacement -- full table replacement-- Select datalength

What is SQL injection?Many website programs do not judge the validity of user input data when writing, which poses security risks to applications. You can submit a piece of database query code (usually in the address bar of a browser and access

There are many reasons for slow query speed. The following are common causes:1. No index or no index is used (this is the most common problem of slow query and is a defect in programming)2. Low I/O throughput, resulting in a bottleneck effect.3. the

Use the Enterprise Manager to set a regular automatic backup plan for databases.1. Open Enterprise Manager and double-click to open your server2. Click Tools in the menu above --> select Database Maintenance Scheduler3. Next, select the data to be

Definition of stored procedures, Stored Procedure (Stored Procedure) is a set of SQL statements for specific functions. The set is compiled and Stored in the database. You can specify the name of the Stored Procedure and provide parameters, if the

In the data room charging system, there are several such situations: Start date and end date. I believe you are smart enough to figure out why there are two date controls! Yes, it is to find records in these two date ranges from a table! Some people

When you find that the database query performance is very slow, you will think of adding indexes to optimize the database query performance. However, in the face of a complicated SQL statement, finding an optimized index combination is for the human

This series of articles I saw in the sqlskill.com's PAUL blog, many misunderstandings are more typical and representative, the original from the T-SQL Tuesday #11: Misconceptions about... EVERYTHING !!, Our team has translated and organized the

When you delete a database user under ms sql2005, the following message is displayed"The database entity has a schema in the database and cannot be deleted."Error Solution1. Check whether the user exists under the security-> architecture. If yes,