转载：Perl Tutorial: Regular Expressions (Regex), File IO and Text Processing Perl is famous for processing text files via regular expressions. # 1. Regular Expressions in Perl A Regular Expression (or Regex) is a pattern (or filter) that describes a set of strings that matches the pattern. In other...

转载: Building a CodePen Type Editor from Scratch Building a CodePen Type Editor from ScratchWanting to show live examples of code on your website is very common, if you want to do it today there are a few services that provide that ability. However, if you are like me, you would rather roll your...

转载：SQL Auto Increment: How to Use It in Different Databases - Database Star SQL auto-increment is a feature that allows you to generate a unique number when inserting rows. Learn how to set this up in SQL Server, MySQL, PostgreSQL, and Oracle in this article. # What is SQL Auto...

# Divide / 12select cast(30 as float) / 120, 30::float / 120, 30 / 120;--0.25 0.25 0 # VARIADIC Parameter 参数 nums 是一个数组，可以传入任意多个参数；然后计算它们的和值。 例如： SELECT sum_num(1,2), sum_num(1,2,3); sum_num sum_num 3 6 1234567891011CREATE OR REPLACE FUNCTION sum_num(VARIADIC nums numeric[])RETURNS numericAS...

转载：Bill of Lading: Meaning, Types, Example, and Purpose # What Is a Bill of Lading? A bill of lading (BL or BoL) is a legal document issued by a carrier (transportation company) to a shipper that details the type, quantity, and destination of the goods being carried. A bill of lading also serves as...

转载：Shipping Dates vs. Delivery Dates: What’s the Difference? 45% of customers abandon their carts due to unsatisfactory delivery options. Without crucial details like shipping dates and delivery dates built into your online experience, you could be losing sales. The ecommerce landscape is...

转载：generate_series: an Oracle implementation in light of SQL Design Patterns - The Spatial Database Advisor # GENERATE_SERIES There is a very useful function in PostgreSQL called generate_series that can be used to generate a series of integer numbers from some start value to an end value with an...

The DBMS_RANDOM package provides a built-in random number generator. # Using DBMS_RANDOM The RANDOM function produces integers in the range [-2^^31, 2^^31). The VALUE function produces numbers in the range [0,1) with 38 digits of precision. DBMS_RANDOM can be explicitly initialized but does not...