how to use if else in sql query

Cause Analysis and Solution of slow SQL query speed, and cause analysis of slow SQL query speed Cause Analysis and Solution for slow SQL query speed There are many reasons for slow query speed. The following are common causes:　　1. No index or no

Next: T-SQL Dynamic Query (3)--Static SQLObjective:There's a lot of talk about dynamic queries, and this article describes some of the ways to use dynamic SQL to solve dynamic queries.Why use Dynamic sql:In many projects, dynamic SQL is widely used

MS SQL Server Query optimization methodThere are many reasons for the slow speed of queries, which are common1, no indexes, or no indexes (this is the most common problem with query slowness, is the flaw in programming)2, I/o throughput is small,

--Simple case function when ' 1 ' then ' Male ' when ' 2 ' then ' women ' else ' other ' end--case search function case when sex = ' 1 ' Then ' man ' when Sex = ' 2 ' Then ' women ' else ' other ' ENDIn both of these ways,

Case has two formats. Simple case function and case search function.--Simple case function when ' 1 ' then ' Male ' when ' 2 ' then ' women ' else ' other ' end--case search function case when sex = ' 1 ' Then ' man ' when

Case has two formats. Simple case function and case search function.--Simple case function when ' 1 ' then ' Male ' when ' 2 ' then ' women ' else ' other ' end--case search function case when sex = ' 1 ' Then ' man ' when

Case has two formats. Simple case function and case search function.--Simple Case functionCase SexWhen ' 1 ' Then ' men 'When ' 2 ' then ' women 'Else ' other ' END--case search functioncase If sex = ' 1 ' Then ' man 'When sex = ' 2 ' Then ' women

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

Case has two formats. Simple case function and case search function.--Simple Case functionCase SexWhen ' 1 ' Then ' men 'When ' 2 ' then ' women 'Else ' other ' END--case search functioncase If sex = ' 1 ' Then ' man 'When sex = ' 2 ' Then ' women

SQL server2005 optimization Query Speed 50 Summary of methods SQL server2005 Optimization Query speed 51 method Query Slow reason many, common following several, we can refer to below.I/O throughput is small, creating a bottleneck effect.A computed