if condition in sql query example

35. use SQL query analyzer and SQL profilerUse SQL query AnalyzerUse SQL profilerOptimize T-SQL statementSummaryIn this chapter, we will continue with the description of the pre-stored procedures in Chapter 21st. This chapter describes how to use

1. A question describes how an SQL statement is executed in a database? I believe many people will be interested in this issue. Of course, it is a huge problem to fully describe the lifecycle of an SQL statement in the database, it covers a series

Source: Drill down into the MySQL kernel1 Problem DescriptionHow does a SQL work in a database? I believe a lot of people will be interested in this problem. Of course, to fully describe a SQL in the database life cycle, this is a very big problem,

thinkphp query Language with coherent operation can be very good to solve the complex business logic requirements, this article we first to in-depth understanding of the framework of the query language. 1. Query Language Introduction thinkphp

1. Description of the problemHow does a SQL work in a database? I believe a lot of people will be interested in this problem. Of course, to fully describe a SQL in the database life cycle, this is a very big problem, covering the SQL lexical parsing,

13. T-SQL and SQL query AnalyzerWhat is SQL?What is T-SQL?Introduce new features of T-SQLHow to Use T-SQLSummaryIn this chapter, we will introduce some basic concepts about the Structured Query Language and transact-SQL and their differences. This

In the previous article, we learned the basic data CURD method, but in more cases, due to the difference in business logic, CURD operations are often not that simple, especially under complicated business logic, this is also a shortcoming of the

Analysis of Index Condition Pushdown (under the ICP Index Condition) and Multi-Range Read (MRR Index Multi-Range lookup) query optimization in MySQL,   Source: http://www.cnblogs.com/wy123/p/7374078.html(The Source retained is not the right of

In the previous article we have mastered the basic data curd method, but in more cases, due to the differences in business logic, curd operations are often not so simple, especially complex business logic below, this is the ActiveRecord mode of

To implement multi-condition query, if the value is 0, it is not limited to any conditions. how can I use SQL? for example, if a certain type of store in a region is not limited to a Chinese query, the where Region value is not required, but only