Call Statement Is Used Mostly in Sql
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Database Concepts 7Th Edition
Database Concepts 7th Edition David M. Kroenke • David J. Auer Online Appendix E SQL Views, SQL/PSM and Importing Data Database Concepts SQL Views, SQL/PSM and Importing Data Appendix E All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Printed in the United States of America. Appendix E — 10 9 8 7 6 5 4 3 2 1 E-2 Database Concepts SQL Views, SQL/PSM and Importing Data Appendix E Appendix Objectives • To understand the reasons for using SQL views • To use SQL statements to create and query SQL views • To understand SQL/Persistent Stored Modules (SQL/PSM) • To create and use SQL user-defined functions • To import Microsoft Excel worksheet data into a database What is the Purpose of this Appendix? In Chapter 3, we discussed SQL in depth. We discussed two basic categories of SQL statements: data definition language (DDL) statements, which are used for creating tables, relationships, and other structures, and data manipulation language (DML) statements, which are used for querying and modifying data. In this appendix, which should be studied immediately after Chapter 3, we: • Describe and illustrate SQL views, which extend the DML capabilities of SQL. • Describe and illustrate SQL Persistent Stored Modules (SQL/PSM), and create user-defined functions. • Describe and use DBMS data import techniques to import Microsoft Excel worksheet data into a database. E-3 Database Concepts SQL Views, SQL/PSM and Importing Data Appendix E Creating SQL Views An SQL view is a virtual table that is constructed from other tables or views. -
Support Aggregate Analytic Window Function Over Large Data by Spilling
Support Aggregate Analytic Window Function over Large Data by Spilling Xing Shi and Chao Wang Guangdong University of Technology, Guangzhou, Guangdong 510006, China North China University of Technology, Beijing 100144, China Abstract. Analytic function, also called window function, is to query the aggregation of data over a sliding window. For example, a simple query over the online stock platform is to return the average price of a stock of the last three days. These functions are commonly used features in SQL databases. They are supported in most of the commercial databases. With the increasing usage of cloud data infra and machine learning technology, the frequency of queries with analytic window functions rises. Some analytic functions only require const space in memory to store the state, such as SUM, AVG, while others require linear space, such as MIN, MAX. When the window is extremely large, the memory space to store the state may be too large. In this case, we need to spill the state to disk, which is a heavy operation. In this paper, we proposed an algorithm to manipulate the state data in the disk to reduce the disk I/O to make spill available and efficiency. We analyze the complexity of the algorithm with different data distribution. 1. Introducion In this paper, we develop novel spill techniques for analytic window function in SQL databases. And discuss different various types of aggregate queries, e.g., COUNT, AVG, SUM, MAX, MIN, etc., over a relational table. Aggregate analytic function, also called aggregate window function, is to query the aggregation of data over a sliding window. -
Multiple Condition Where Clause Sql
Multiple Condition Where Clause Sql Superlunar or departed, Fazeel never trichinised any interferon! Vegetative and Czechoslovak Hendrick instructs tearfully and bellyings his tupelo dispensatorily and unrecognizably. Diachronic Gaston tote her endgame so vaporously that Benny rejuvenize very dauntingly. Codeigniter provide set class function for each mysql function like where clause, join etc. The condition into some tests to write multiple conditions that clause to combine two conditions how would you occasionally, you separate privacy: as many times. Sometimes, you may not remember exactly the data that you want to search. OR conditions allow you to test multiple conditions. All conditions where condition is considered a row. Issue date vary each bottle of drawing numbers. How sql multiple conditions in clause condition for column for your needs work now query you take on clauses within a static list. The challenge join combination for joining the tables is found herself trying all possibilities. TOP function, if that gives you no idea. New replies are writing longer allowed. Thank you for your feedback! Then try the examples in your own database! Here, we have to provide filters or conditions. The conditions like clause to make more content is used then will identify problems, model and arrangement of operators. Thanks for your help. Thanks for war help. Multiple conditions on the friendly column up the discount clause. This sql where clause, you have to define multiple values you, we have to basic syntax. But your suggestion is more readable and straight each way out implement. Use parenthesis to set of explicit groups of contents open source code. -
SQL DELETE Table in SQL, DELETE Statement Is Used to Delete Rows from a Table
SQL is a standard language for storing, manipulating and retrieving data in databases. What is SQL? SQL stands for Structured Query Language SQL lets you access and manipulate databases SQL became a standard of the American National Standards Institute (ANSI) in 1986, and of the International Organization for Standardization (ISO) in 1987 What Can SQL do? SQL can execute queries against a database SQL can retrieve data from a database SQL can insert records in a database SQL can update records in a database SQL can delete records from a database SQL can create new databases SQL can create new tables in a database SQL can create stored procedures in a database SQL can create views in a database SQL can set permissions on tables, procedures, and views Using SQL in Your Web Site To build a web site that shows data from a database, you will need: An RDBMS database program (i.e. MS Access, SQL Server, MySQL) To use a server-side scripting language, like PHP or ASP To use SQL to get the data you want To use HTML / CSS to style the page RDBMS RDBMS stands for Relational Database Management System. RDBMS is the basis for SQL, and for all modern database systems such as MS SQL Server, IBM DB2, Oracle, MySQL, and Microsoft Access. The data in RDBMS is stored in database objects called tables. A table is a collection of related data entries and it consists of columns and rows. SQL Table SQL Table is a collection of data which is organized in terms of rows and columns. -
Scalable Computation of Acyclic Joins
Scalable Computation of Acyclic Joins (Extended Abstract) Anna Pagh Rasmus Pagh [email protected] [email protected] IT University of Copenhagen Rued Langgaards Vej 7, 2300 København S Denmark ABSTRACT 1. INTRODUCTION The join operation of relational algebra is a cornerstone of The relational model and relational algebra, due to Edgar relational database systems. Computing the join of several F. Codd [3] underlies the majority of today’s database man- relations is NP-hard in general, whereas special (and typi- agement systems. Essential to the ability to express queries cal) cases are tractable. This paper considers joins having in relational algebra is the natural join operation, and its an acyclic join graph, for which current methods initially variants. In a typical relational algebra expression there will apply a full reducer to efficiently eliminate tuples that will be a number of joins. Determining how to compute these not contribute to the result of the join. From a worst-case joins in a database management system is at the heart of perspective, previous algorithms for computing an acyclic query optimization, a long-standing and active field of de- join of k fully reduced relations, occupying a total of n ≥ k velopment in academic and industrial database research. A blocks on disk, use Ω((n + z)k) I/Os, where z is the size of very challenging case, and the topic of most database re- the join result in blocks. search, is when data is so large that it needs to reside on In this paper we show how to compute the join in a time secondary memory. -
SQL Stored Procedures
Agenda Key:31MA Session Number:409094 DB2 for IBM i: SQL Stored Procedures Tom McKinley ([email protected]) DB2 for IBM i consultant IBM Lab Services 8 Copyright IBM Corporation, 2009. All Rights Reserved. This publication may refer to products that are not currently available in your country. IBM makes no commitment to make available any products referred to herein. What is a Stored Procedure? • Just a called program – Called from SQL-based interfaces via SQL CALL statement • Supports input and output parameters – Result sets on some interfaces • Follows security model of iSeries – Enables you to secure your data – iSeries adopted authority model can be leveraged • Useful for moving host-centric applications to distributed applications 2 © 2009 IBM Corporation What is a Stored Procedure? • Performance savings in distributed computing environments by dramatically reducing the number of flows (requests) to the database engine – One request initiates multiple transactions and processes R R e e q q u u DB2 for i5/OS DB2DB2 for for i5/OS e e AS/400 s s t t SP o o r r • Performance improvements further enhanced by the option of providing result sets back to ODBC, JDBC, .NET & CLI clients 3 © 2009 IBM Corporation Recipe for a Stored Procedure... 1 Create it CREATE PROCEDURE total_val (IN Member# CHAR(6), OUT total DECIMAL(12,2)) LANGUAGE SQL BEGIN SELECT SUM(curr_balance) INTO total FROM accounts WHERE account_owner=Member# AND account_type IN ('C','S','M') END 2 Call it (from an SQL interface) over and over CALL total_val(‘123456’, :balance) 4 © 2009 IBM Corporation Stored Procedures • DB2 for i5/OS supports two types of stored procedures 1. -
“A Relational Model of Data for Large Shared Data Banks”
“A RELATIONAL MODEL OF DATA FOR LARGE SHARED DATA BANKS” Through the internet, I find more information about Edgar F. Codd. He is a mathematician and computer scientist who laid the theoretical foundation for relational databases--the standard method by which information is organized in and retrieved from computers. In 1981, he received the A. M. Turing Award, the highest honor in the computer science field for his fundamental and continuing contributions to the theory and practice of database management systems. This paper is concerned with the application of elementary relation theory to systems which provide shared access to large banks of formatted data. It is divided into two sections. In section 1, a relational model of data is proposed as a basis for protecting users of formatted data systems from the potentially disruptive changes in data representation caused by growth in the data bank and changes in traffic. A normal form for the time-varying collection of relationships is introduced. In Section 2, certain operations on relations are discussed and applied to the problems of redundancy and consistency in the user's model. Relational model provides a means of describing data with its natural structure only--that is, without superimposing any additional structure for machine representation purposes. Accordingly, it provides a basis for a high level data language which will yield maximal independence between programs on the one hand and machine representation and organization of data on the other. A further advantage of the relational view is that it forms a sound basis for treating derivability, redundancy, and consistency of relations. -
SQL/PSM Stored Procedures Basic PSM Form Parameters In
Stored Procedures PSM, or “persistent, stored modules,” SQL/PSM allows us to store procedures as database schema elements. PSM = a mixture of conventional Procedures Stored in the Database statements (if, while, etc.) and SQL. General-Purpose Programming Lets us do things we cannot do in SQL alone. 1 2 Basic PSM Form Parameters in PSM CREATE PROCEDURE <name> ( Unlike the usual name-type pairs in <parameter list> ) languages like C, PSM uses mode- <optional local declarations> name-type triples, where the mode can be: <body>; IN = procedure uses value, does not Function alternative: change value. CREATE FUNCTION <name> ( OUT = procedure changes, does not use. <parameter list> ) RETURNS <type> INOUT = both. 3 4 1 Example: Stored Procedure The Procedure Let’s write a procedure that takes two CREATE PROCEDURE JoeMenu ( arguments b and p, and adds a tuple IN b CHAR(20), Parameters are both to Sells(bar, beer, price) that has bar = IN p REAL read-only, not changed ’Joe’’s Bar’, beer = b, and price = p. ) Used by Joe to add to his menu more easily. INSERT INTO Sells The body --- VALUES(’Joe’’s Bar’, b, p); a single insertion 5 6 Invoking Procedures Types of PSM statements --- (1) Use SQL/PSM statement CALL, with the RETURN <expression> sets the return name of the desired procedure and value of a function. arguments. Unlike C, etc., RETURN does not terminate Example: function execution. CALL JoeMenu(’Moosedrool’, 5.00); DECLARE <name> <type> used to declare local variables. Functions used in SQL expressions wherever a value of their return type is appropriate. -
Join , Sub Queries and Set Operators Obtaining Data from Multiple Tables
Join , Sub queries and set operators Obtaining Data from Multiple Tables EMPLOYEES DEPARTMENTS … … Cartesian Products – A Cartesian product is formed when: • A join condition is omitted • A join condition is invalid • All rows in the first table are joined to all rows in the second table – To avoid a Cartesian product, always include a valid join condition in a WHERE clause. Generating a Cartesian Product EMPLOYEES (20 rows) DEPARTMENTS (8 rows) … Cartesian product: 20 x 8 = 160 rows … Types of Oracle-Proprietary Joins – Equijoin – Nonequijoin – Outer join – Self-join Joining Tables Using Oracle Syntax • Use a join to query data from more than one table: SELECT table1.column, table2.column FROM table1, table2 WHERE table1.column1 = table2.column2; – Write the join condition in the WHERE clause. – Prefix the column name with the table name when the same column name appears in more than one table. Qualifying Ambiguous Column Names – Use table prefixes to qualify column names that are in multiple tables. – Use table prefixes to improve performance. – Instead of full table name prefixes, use table aliases. – Table aliases give a table a shorter name. • Keeps SQL code smaller, uses less memory – Use column aliases to distinguish columns that have identical names, but reside in different tables. Equijoins EMPLOYEES DEPARTMENTS Primary key … Foreign key Retrieving Records with Equijoins SELECT e.employee_id, e.last_name, e.department_id, d.department_id, d.location_id FROM employees e, departments d WHERE e.department_id = d.department_id; … Retrieving Records with Equijoins: Example SELECT d.department_id, d.department_name, d.location_id, l.city FROM departments d, locations l WHERE d.location_id = l.location_id; Additional Search Conditions Using the AND Operator SELECT d.department_id, d.department_name, l.city FROM departments d, locations l WHERE d.location_id = l.location_id AND d.department_id IN (20, 50); Joining More than Two Tables EMPLOYEES DEPARTMENTS LOCATIONS … • To join n tables together, you need a minimum of n–1 • join conditions. -
SQL: Programming Introduction to Databases Compsci 316 Fall 2019 2 Announcements (Mon., Sep
SQL: Programming Introduction to Databases CompSci 316 Fall 2019 2 Announcements (Mon., Sep. 30) • Please fill out the RATest survey (1 free pt on midterm) • Gradiance SQL Recursion exercise assigned • Homework 2 + Gradiance SQL Constraints due tonight! • Wednesday • Midterm in class • Open-book, open-notes • Same format as sample midterm (posted in Sakai) • Gradiance SQL Triggers/Views due • After fall break • Project milestone 1 due; remember members.txt • Gradiance SQL Recursion due 3 Motivation • Pros and cons of SQL • Very high-level, possible to optimize • Not intended for general-purpose computation • Solutions • Augment SQL with constructs from general-purpose programming languages • E.g.: SQL/PSM • Use SQL together with general-purpose programming languages: many possibilities • Through an API, e.g., Python psycopg2 • Embedded SQL, e.g., in C • Automatic obJect-relational mapping, e.g.: Python SQLAlchemy • Extending programming languages with SQL-like constructs, e.g.: LINQ 4 An “impedance mismatch” • SQL operates on a set of records at a time • Typical low-level general-purpose programming languages operate on one record at a time • Less of an issue for functional programming languages FSolution: cursor • Open (a result table): position the cursor before the first row • Get next: move the cursor to the next row and return that row; raise a flag if there is no such row • Close: clean up and release DBMS resources FFound in virtually every database language/API • With slightly different syntaxes FSome support more positioning and movement options, modification at the current position, etc. 5 Augmenting SQL: SQL/PSM • PSM = Persistent Stored Modules • CREATE PROCEDURE proc_name(param_decls) local_decls proc_body; • CREATE FUNCTION func_name(param_decls) RETURNS return_type local_decls func_body; • CALL proc_name(params); • Inside procedure body: SET variable = CALL func_name(params); 6 SQL/PSM example CREATE FUNCTION SetMaxPop(IN newMaxPop FLOAT) RETURNS INT -- Enforce newMaxPop; return # rows modified. -
SQL from Wikipedia, the Free Encyclopedia Jump To: Navigation
SQL From Wikipedia, the free encyclopedia Jump to: navigation, search This article is about the database language. For the airport with IATA code SQL, see San Carlos Airport. SQL Paradigm Multi-paradigm Appeared in 1974 Designed by Donald D. Chamberlin Raymond F. Boyce Developer IBM Stable release SQL:2008 (2008) Typing discipline Static, strong Major implementations Many Dialects SQL-86, SQL-89, SQL-92, SQL:1999, SQL:2003, SQL:2008 Influenced by Datalog Influenced Agena, CQL, LINQ, Windows PowerShell OS Cross-platform SQL (officially pronounced /ˌɛskjuːˈɛl/ like "S-Q-L" but is often pronounced / ˈsiːkwəl/ like "Sequel"),[1] often referred to as Structured Query Language,[2] [3] is a database computer language designed for managing data in relational database management systems (RDBMS), and originally based upon relational algebra. Its scope includes data insert, query, update and delete, schema creation and modification, and data access control. SQL was one of the first languages for Edgar F. Codd's relational model in his influential 1970 paper, "A Relational Model of Data for Large Shared Data Banks"[4] and became the most widely used language for relational databases.[2][5] Contents [hide] * 1 History * 2 Language elements o 2.1 Queries + 2.1.1 Null and three-valued logic (3VL) o 2.2 Data manipulation o 2.3 Transaction controls o 2.4 Data definition o 2.5 Data types + 2.5.1 Character strings + 2.5.2 Bit strings + 2.5.3 Numbers + 2.5.4 Date and time o 2.6 Data control o 2.7 Procedural extensions * 3 Criticisms of SQL o 3.1 Cross-vendor portability * 4 Standardization o 4.1 Standard structure * 5 Alternatives to SQL * 6 See also * 7 References * 8 External links [edit] History SQL was developed at IBM by Donald D. -
If Else Condition in Sql Where Clause
If Else Condition In Sql Where Clause Self-styled and charged Ransell ensnare while balkier Ian eulogizes her antipodean pronominally and reprobates exclusively. Myxomycete and bractless Waldo release: which Ender is trimorphic enough? Backbreaking Chas still moonlights: convective and clerkish Hayes nestle quite unalterably but peises her primulas extravagantly. The where clause is an index and operator, when into case expressions that requires to change it take the sql if else condition in where clause also a condition has been added code. This url below and henry for posting this else if condition sql where clause in sql databases support. And health department are included in if else condition clause in sql where clause in the better to run the. If no searchcondition matches the inventory clause statementlist executes Each statementlist consists of one button more SQL statements an empty statementlist is. NEVERMIND I pound IT, btw i am using MERGE i hope for same logic can be applied for each update aswell. As sql if else condition where clause in sql to control on the time, a graphical view, or null it finds a merge it. For constructing conditional statements in stored procedures if statement, based on several. That is effectively turning off execution plan caching for that statement. SQL procedure will continue to run after you attribute the program. Not evaluated as following statement multiple if else condition in where clause in. The where only has been created previously working on first true branch being taken, else if condition sql in where clause and then by doing so.