Search results
Our SQL tutorial will teach you how to use SQL in: MySQL, SQL Server, MS Access, Oracle, Sybase, Informix, Postgres, and other database systems. Start learning SQL now » Examples in Each Chapter
1 cze 2021 · Standard SQL Functions Cheat Sheet. TEXT FUNCTIONS. CONCATENATION. Use the || operator to concatenate two strings: SELECT 'Hi ' || 'there!'; -- result: Hi there! Remember that you can concatenate only character strings using. ||. Use this trick for numbers: SELECT '' || 4 || 2;
Standard SQL Functions Cheat Sheet. CASE WHEN. The basic version of . CASE WHEN. checks if the values are equal (e.g., if. fee is equal to 50, then 'normal' is returned). If there isn't a matching value in the CASE WHEN, then the ELSE value will be returned (e.g., if fee is equal to 49, then 'not available' will show up. SELECT CASE fee WHEN 50 ...
This reference contains a complete description of the Structured Query Language (SQL) used to manage information in an Oracle Database. Oracle SQL is a superset of the American National Standards Institute (ANSI) and the International Organization for Standardization (ISO) SQL:2011 standard. This Preface contains these topics: • Audience
Employ SQL functions to generate customized data. Create reports of aggregated data. Use the SET operators to create subsets of data. Run data manipulation statements (DML) in Oracle Database 11g. Run data definition language (DDL) statements to create schema objects. Identify the major structural components of Oracle Database 11g.
What is SQL? Declarative. − Say “what to do” rather than “how to do it”. Avoid data-manipulation details needed by procedural languages. − Database engine figures out “best” way to execute query. Called “query optimization”. Crucial for performance: “best” can be a million times faster than “worst”. Data independent.
25 lut 2018 · Table of Contents v Table of Contents INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 About This ...
