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

C++20 ❤ SQL John R Bandela, MDOverview u SQL u C++ Example u Implementation techniques u fixed_string u meta_struct u Parsing compile time strings into meta_structsOverview v SQL v 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 u Traditional Lots of information available u Vulnerable to sql injection of developer not careful u Use dynamic typingDomain Specific Language u Use types to encode SQL u Looks more like regular C++ u Typically requires

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

'dbListResults_SQLiteConnection.R' 'dbListTables_SQLiteConnection.R' 'dbQuoteIdentifier_SQLiteConnection_SQL.R' 'dbQuoteIdentifier_SQLiteConnection_character.R' 'dbReadTable_SQLiteConnection_character.R' 'db 'dbSendQuery_SQLiteConnection_character.R' 'dbUnloadDriver_SQLiteDriver.R' 'dbUnquoteIdentifier_SQLiteConnection_SQL.R' 'dbWriteTable_SQLiteConnection_character_character.R' 'dbWriteTable_SQLiteConnection_character_data Needed for compatibility with generic. Otherwise ignored. field.types character vector of named SQL field types where the names are the names of new table’s columns. If missing, types inferred with DBI::dbDataType())

implements a self-contained, serverless, zero-configuration, transactional SQL database engine. SQLite is the most widely deployed SQL database engine in the world. The source code for SQLite is in the public secure_delete Pragma ............................................................................. 80 sql_trace Pragma ..................................................................................... SQLite Injection .................................................................... 120 Preventing SQL Injection: ....................................................................... 120 SQLite Explain

to an attribute of that record • relational databases typically use Structured Query Language (SQL) to define, manage, and search data 2 Why use a database? • powerful: can search, filter, combine abstract: layer of abstraction between stored data and app(s) common syntax: database programs use same SQL commands 3 Relational database • A database is a set of tables • Each table has a primary key a playlist) Rows: Fixed number of columns Tables: Variable number of rows 9 SQL • Structured Query Language (SQL): a language for searching and updating a database – a standard syntax that is

Table of Contents SQL Commands SQL Keywords SQLite Program Dot Commands ​SQLite Statements ​ These SQL Statements are organized by their CRUD function on the table or database - Create program closes. Note​ this is a SQLite program statement to open the program (different from SQL commands) sqlite3 shelter.db CREATE a table CREATE TABLE ( DROP TABLE pets; SQLite Keywords These SQLite keywords are to be used in conjunction with SQL commands. PRIMARY KEY CREATE TABLE ( ​PRIMARY KEY​

c u t e a S Q L S t a t e m e n t T h e A P I t o r u n a q u e r y i s : db.run(sql, [param, ...], [callback]) sql: t h e S Q L q u e r y t o r u n param ( op t i on a l ) : a r gu m e n t s f or p u t e a S Q L S t a t e m e n t let sql = 'INSERT INTO user (name, email, password) VALUES (?,?,?)'; let params = ['Bob', 'bob@bob.com', 'swordfish']; db.run(sql, params, (err, result) => { if (err) o r u n a f u n c t i on on e v e r y r e s u l t f r om a q u e r y i s : db.all(sql, [param, ...], [callback] sql: t h e S Q L q u e r y t o r u n param ( op t i on a l ) : a r gu m e n t s f or p