how to get count 0 in sql query

Original address: http://www.cnblogs.com/lyhabc/p/3367274.htmlBefore reading this article, you can read the following article firstSQL Server's unique task scheduling algorithm "Sqlos"Task Scheduler for SQL Server Sqlos [go]Translated

Read SQL Server query planRead Catalogue Begin How SQL Server looks for records SQL Server Join method More specific execution procedures Index statistics: The choice of the query plan is based on Optimizing View Queries

First, the practical, the misunderstanding of the use of the indexThe purpose of the theory is to apply. Although we have just listed when clustered or nonclustered indexes should be used, in practice the above rules are easily overlooked or cannot

Read Catalogue Begin How SQL Server looks for records SQL Server Join method More specific execution procedures Index statistics: The choice of the query plan is based on Optimizing View Queries Recommended

In DB2, the sum function used to replace the count query is to calculate and sum the column values. The www.2cto.com count function accumulates the columns that meet the conditions and adds one when the conditions are met. The count function is

How to display 0 in conditional [Group by] Report in count () SQL query Challenge:Let me assume this: we have two tables, one is regions table with all region information (east, west, etc .) and we have another table with sales information. now, we

SQL tuning is primarily about reducing the number of consistent gets and physical reads. COUNT (1) is compared with COUNT (*): If your datasheet does not have a primary key, then count (1) is faster than COUNT (*)If you have a primary key, the

Optimizing queries can be a common thing for SQL Server optimizations. Since the optimization of database is a wide topic in itself, this article only talks about how to understand SQL Server query plan when optimizing query. After all, my knowledge

The most obvious feature of SQL differs from other programming languages is the order in which the code is processed. In a large number programming language, code is processed in encoded order, but in the SQL language, the first processed clause is

Today to see a Bo Friends of the article, feel good, reprint, hope to help you, more articles, please visit: http://blog.haoitsoft.com1, no index or no index (this is the most common problem of slow query, is the defect of program design)2, I/O