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This article explains how to split an SQL statement with one or more left JOIN or right join into multiple SQL statements. MySQL query efficiency is very low, especially large data, and high concurrency, the index can not solve the problem, the best way is to split the SQL statement into multiple single table query SQL

handling of column fields SQL Case Do the column processing Sql> Select deptno,sum (SAL) from the EMP Group by DEPTNO; Select Case When deptno=10 Then ' ACCOUNTING ' When deptno=20 Then ' Reserch ' When deptno=30 Then ' SALES ' End sum (SAL) from EMP GROUP BY Deptno handling of column fields SQL Decode There is also the case that when nothing

section assumes that you are familiar with the following topics: Data Transmission Service Link server and Distributed Query Ado development in Visual Basic Back to TopExample import and append The example SQL statement used in this article demonstrates the "Create Table" query. This query imports Excel data into a new SQL Server table by using the Select... into... from syntax. As shown in the code e

Alias for SQL1. You cannot use the alias of the column name in the WHERE clause, that is, the select name T from EMP where t>2999; is not allowed2. Benefits of using aliases:Improve the readability of SQLImprove the efficiency of SQL parsing executionGrammar checkSemantic checkShared Pool ChecksBuild the execution treePerform3. Hard parsing and soft parsing of SQL?Execution Order of SQL1. From statement--wh

1. View the version of the database SELECT @ @version Several common SQL Server patched version numbers: 8.00.194 Microsoft SQL Server 2000 8.00.384 Microsoft SQL Server SP1 8.00.532 Microsoft SQL Server SP2 8.00.760 Microsoft SQL Server SP3 8.00.818 Microsoft

1. View the version of the database SELECT @ @version 2. View the machine operating system parameters of the database EXEC master.. xp_msver 3. View Database Startup Parameters sp_configure 4. View Database Startup time Select CONVERT (varchar, login_time,120) from master. sysprocesses where spid=1 To view the database server name and instance name print ' Server Name ... ...: ' + CONVERT (varchar (), @ @SERVERNAME) (@, @) print ' Instance ... ...: ' + CONVERT (varchar) (@ @SERVICENAME)., D., ".

server| Data | database | statement 1. View the version of the databaseSELECT @ @version2. View the machine operating system parameters of the databaseEXEC master.. xp_msver3. View Database Startup Parameterssp_configure4. View Database Startup timeSelect CONVERT (varchar, login_time,120) from master. sysprocesses where spid=1To view the database server name and instance nameprint ' Server Name ... ...: ' + CONVERT (varchar (), @ @SERVERNAME), ".print ' Instance ....: ' + CONVERT (varchar), @ @S

Tags: free ODBC freetds tle project download server using HTTPSSQL SQL statements and stored procedures for SQL Server execution with FreeTDS under Linux Http://www.linuxidc.com/Linux/2012-06/61617.htm FreeTDS related Http://www.knowsky.com/616936.html The shell accepts the value returned by the stored procedure Http://blog.chinaunix.net/uid-22948773-id-3318716.html MyBatis call stored procedure and return

database parameterized ModeThere are two ways to parameterize a database, simple and mandatory (forced), and the default parameterization is "simple" by default.In simple mode, if the SQL is sent every time, unless it is exactly the same, it will be recompiled (special circumstances will be automatically parameterized, it is the focus of this article)The mandatory mode is to force the Adhoc SQL to be parame

SQL Server-Basic-classic SQL statements, server-SQL 1 classic SQL statement 2 basics 3 1. Description: CREATE DATABASE 4 CREATE database-name 5 2. Description: delete DATABASE 6 drop database dbname 7 3. Description: back up SQL server 8 --- create device 9 USE master 10 EXE

A few questions about SQL (SQL advanced) and SQL advanced When we get a question, we are not eager to answer the question. It will not be worth the candle, but to analyze the ideas, methods, and objectives, we also need to think about whether there are simple methods or general methods to achieve the same effect. In fact, this kind of inertial thinking was introd

like '% @ str %'Create an encrypted stored procedure or function WITH the with encryption parameter before theYou can use sp_decrypt to decrypt encrypted stored procedures and functions.10. View user and process information in the databaseSp_whoView information about active users and processes in the SQL Server databaseSp_who 'active'View the locks in the SQL Server databaseSp_lockProcess No. 1--50 is used

Often develop ASP but for the meticulous statement, the truth is not very clear, here a simple introduction. Under normal circumstances Read the data with Rs.Open sql,conn,1,1 Modifying data: Rs.Open sql,conn,1,3 Delete data: Directly to Conn.execute ("Delete * from new where id=1"). The Rs.Open syntax is as follows: Rs. Open Source,activeconnection,cursortype,locktype Source is a

Tags: ash text results SQL tuning SRC completion need to end TunA few days ago, a user developed QQ to find me, as follows:The free Dolphin. 16:12:01The island owner, my SQL can not find the results, could you help me see?Orchid Island Main 16:12:10How long is the result?The Free Dolphin 16:12:17How long has not produced the result, has not seen the result.Orchid Island Main 16:12:26Oh, good.Orchid Island M

After a DML statement is executed, the results of the DML statement are stored in four cursor attributes, which are used to controlProgramProcess or understand the program status. When running a DML statement, PL/SQL opens a built-in cursor and processes the result. The cursor is an area in the memory that maintains the query result. The cursor is opened when running the DML statement and closed after completion. Only

About T-SQL and SQL Enterprise Manager, SQL Enterprise After reading the database video, we often use two methods in the video. One is the SQL Enterprise Manager, and the other is the T-SQL (Tansact-SQL ). For the first method, it