if else statement in sql select query

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,

The first step: the client sends the statement to the server-side executionWhen we execute a SELECT statement on the client, the client sends the SQL statement to the server side, allowing the server-side process to process the statement. That is,

1. Single-Table query: Filter the records in the table according to where conditions, form an intermediate table (this intermediate table is not visible to the user), and then select the corresponding column according to the Select column of select

How do I retrieve the result set of a stored procedure (store Procedure) in a SQL Server query statement (Select)? (2006-12-14 09:25:36)Other descriptions of the same nature as this issue include:How do I get an execution result recordset for

SQL statement case when then else end returns a qualified value, sqlcase Case has two formats Simple Case functions and Case search functions: -- Simple Case function CASE sex WHEN '1' then' male 'when' 2' then' female 'else' other 'ends -- Case

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

50 SQL Query Techniques, query statement examples, 50 SQL statements Student (S #, Sname, Sage, Ssex) Student tableCourse (C #, Cname, T #) CurriculumSC (S #, C #, score) Orders tableTeacher (T #, Tname) Instructor table Problem:1. query the student

MySQL is the most basic SQL syntax. For more information, see. The most basic SQL syntax/Statement of MySQL. For more information, see. DDL-Data Definition Language (Create, Alter, Drop, DECLARE) DML-data manipulation language (Select, Delete,

The following statements in the complete SQL operation are Mssql statements and cannot be used in access. The following statements in the complete SQL operation are Mssql statements and cannot be used in access. SQL classification: DDL-Data

ddl-Data Definition language (create,alter,drop,declare) dml-Data Manipulation Language (Select,delete,update,insert) dcl-Data Control Language (Grant,revoke,commit,rollback) First, briefly introduce the underlying statement: 1, Description: