is a very powerful feature of MyBatis. It enables programmers write the query using the dynamic 
.  MyBatis uses a powerful Dynamic 
 statement. Following are the OGNL based Dynamic 
 expressions provided by MyBatis when, otherwise  trim where, set  foreach  The if Statement  The most common thing to do in dynamic 
 is conditionally include a part of a where clause. For example −  
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 Vitess解析   ⺴⽹网易杭州研究院后台技术组---胡争  Vitess Introduction  • Golang , GTID  • youtube 2011~2015 , github 2000+ star  • vitess provides servers and tools which   facilitate scaling of MySQL databases for  large c/c++  Vitess Features  • dynamic  resharding  • auto-failover  • row-cache  • limit inefficiency SQL   • more client connection  • replication lag optimization  • multi data center  Vitess Topo  Vitess "KeyRange": {      "Start": "",      "End": ""    }  }  Vtgate – Structure  Vtgate – SQL  Example  Vtgate – SQL  Example  Plan SQL 语句 备注  SelectUnshar ded  select * from main1 
  SelectScatte r  select * from user
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  C++20 ❤ SQL 
John R Bandela, MDOverview
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SQL 
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C++ Example
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Implementation techniques
u fixed_string
u meta_struct
u Parsing compile time strings into meta_structsOverview
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SQL 
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C++ Example {price_from_user};Avoiding SQL  Injection Attacks
SELECT orders.id, name, item, price, discount_code
FROM orders JOIN customers ON customers.id = customerid
WHERE price > ?;SQL  Library Options
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Traditional Lots of information available
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Vulnerable to sql  injection of developer not careful
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Use dynamic typingDomain Specific Language
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Use types to encode SQL 
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Looks more like regular C++
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Typically requires
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  OpenPie. All rights reserved. OpenPie Confidential  • Simplify scalar expressions  • Expand simple SQL  functions in-line  • Simplify join tree  Early Preprocessing  @2024 OpenPie. All rights reserved. OpenPie FUNCTION incr4(int) RETURNS int  AS 'SELECT $1 + (2 + 2)' LANGUAGE SQL ;  SELECT incr4(a) FROM foo;  =>  SELECT a + 4 FROM foo;  Expand Simple SQL  Functions in-line  @2024 OpenPie. All rights reserved. OpenPie
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  Postgres Conference China 2016 中国用户大会   PostgreSQL WAL日志解析 与应用   王硕    山东瀚高基础软件股份有限公司    2016Postgres中国用户大会  Postgres Conference China 2016 中国用户大会   CONTENTS   Part  01   Part  02   Part  03   WAL 日志简介
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  Firebird Null Guide  NULL behaviour and pitfalls in Firebird SQL   Paul Vinkenoog  Version 1.2, 30 June 2020  Table of Contents  1. What is NULL? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  4  2. NULL support in Firebird SQL  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  operations will render the entire expression NULL.  This guide explores the behaviour of NULL in Firebird SQL , points out common pitfalls and shows  you how to deal safely with expressions that contain NULL or
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  TiDB: HBase分布式事务与SQL 实现  About me  ● TiDB & Codis founder  ● Golang expert  ● Distributed database developer  ● Currentlly, CEO and co-founder of PingCAP  liuqi@pingcap.com        https://github.com/pingcap/tidb say ?  “Nothing is hotter than SQL -on-Hadoop, and now SQL -on- HBase is fast approaching equal hotness status”           Form HBaseCon 2015  We want more !             SQL  + Transaction(ACID)  TiDB  Features Let’s talk about SQL    How does TiDB map SQL  to KV  User table  RowID(hidden column) name email  1 bob bob@gmail.com  Inside TiDB,each table, column has an unique  ID  How to map SQL  to KV  Let assume
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  Istio控制平面组件原理解析 
朱经惠
2018.08.25
Service Mesh Meetup #3 深圳站关于我
• 朱经惠,ETC车宝平台工程师。
• 喜欢开源,个人开源项目”Jaeger PHP Client”。
• 喜欢研究源码,对NSQ,Jaeger,Istio(控制平面)等go语言开源项目进行
过研究。
• 除了代码还喜欢爬山和第二天睡醒后全身酸疼的感觉。目录Pil
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  第三届中国Rust开发者⼤会  ⽤ egg 孵化你的 SQL  优化器  王润基   RisingWave 内核开发⼯程师 ?  Parser  Binder  Optimizer  Executor  SQL   AST  Logical Plan  Physical Plan Table  Catalog Storage  RisingLight 查询引擎的整体结构  SELECT name, url url  FROM t1 JOIN t2  WHERE t1.id = t2.id    AND name = ‘Bob’  SQL  Logical Plan Physical Plan  Projection  name, url  Filter   t1.id = t2.id  name = “Bob”  Join  Scan   t1(id, name)  Scan   t2(id, url) Filter   #1 = “Bob”  Hash Join   #0 = #2  Scan   $1.1, $1.2  Scan   $2.1, $2.2  Projection   #1, #3  ⼀个 SQL  语句优化的例⼦  基于规则的优化 (RBO) 基于代价的优化 (CBO)  谓词下推  Join  Filter  A B  Join  Filter  A B  Filter  Join  A Join
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          | 1 年前   3