Summary of usage of data processing functions

Date and time processing functions Date and time are stored in corresponding data types and special formats so that they can be sorted or filtered quickly and effectively, and to save physical storage space. Typically, applications do not use a format for storing dates and times, so date and time functions are always used to read and manipulate these values. For this reason, date and time functions play an important role in the MySQL language. The following table lists some commonly used date and time processing functions: This is a good time to revisit where to filter data. So far, we have filtered data using where clauses that compare numbers and text, but data often needs to be filtered by date. Filtering by date requires some additional considerations and the use of special MySQL functions. The first thing to note is the date format used by MySQL. Whenever you specify a date, whether inserting or updating a table value or filtering with a where clause, the date must be in the format yyyy-mm-dd. Therefore, September 1, 2005, is given as 2005-09-01. Although other date formats may work, this is the preferred date format because it excludes ambiguities (e.g., 0

1. Examples of date and time processing functions and numerical processing functions (Usage of data processing functions 2)

Introduction: Date and time processing functions Dates and times are stored in corresponding data types and special formats so that they can be sorted or filtered quickly and effectively, and to save physical storage space in general applications. The format used to store dates and times is not used, so date and time functions are always used to read and process these values. For this reason, date and time functions play an important role in the MySQL language.

##2.

mysql text processing function example (Use of data processing function 1)

Introduction: Text processing function Before we talked about the rtrim() function used to remove spaces at the end of a string, this is how we use the function to process this article. Next we introduce another function, the upper() function:

3.

SQL data processing function introduction

Introduction: What is a function? Like most other computer languages, SQL supports the use of functions to process data. Functions are generally executed on data, and they provide convenience for data conversion and processing, such as rtrim(), which is used to remove trailing spaces. It is an example of a function.

4.

MySQL creates fields + data processing functions + summary data (aggregation functions) + grouped data_MySQL

Introduction: Part of the text description in this article is transferred from MySQL Must Know, which is intended to review MySQL's creation of field data processing functions to summarize data (aggregation functions) to group data Basic knowledge of

5.

SQL must-know notes 6 Using data processing functions

Introduction: Unlike SQL statements, SQL functions are not portable. Code written for a specific SQL implementation may not work correctly in other implementations because of the differences in the implementation of functions by various DBMS vendors. Big difference. Commonly used functions Most SQL implementations support the following types of functions: 1. Text processing function SELECT vend_name, UPPER (vend_name) AS vend_name

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PHP Data processing function

#Introduction: Recently, when processing front-end form input data, I encountered several PHP string processing functions, and I really don’t understand what they do. The API is too vague and I can’t understand it. Please help me explain the difference and function: htmlspecialchars addslashes stripslashes strip_tags ...

7. MySQL data processing function_MySQL

Introduction: MySQL data processing function

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