What is the usage of is, between, in and other operators in PHP?

We have learned so much about PHP, but I wonder what your usage of is, between, in and other operators in PHP is? Have you fully mastered it? If not, then follow this article to continue learning

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is operator: Judgment of null value and Boolean value

There are 4 situations to use:

• xx is null: judge that a certain field is a "null" value - that is, there is no value, xxis not null: judge that a certain field is not a "null" value

• xx is true: Judge a certain field as "true"

• ##xxis false: Judge a certain field as "false" (false): o, 0.0, ". null

• The so-called Boolean value is actually an "alias" of the tinyint(1) type. In essence, it just determines whether a number is 0

between operator: range judgment

is used to judge whether the data value of a certain field is within a given range - suitable for numeric types,

Syntax:

xxbetween值1and值2,含义:
XX字段的值在给定“值1”和“值2”之间，其实相当于:XX=值1 and xx <=值2；

in operator: given the range judgment of certain data

Syntax:

xxin(值1，值2，值3，...-.);含义﹔

means that the value of field XX is One of the listed values ​​​​is considered to have met the conditions; these values ​​are usually scattered and irregular.

If the data it lists has certain rules, it can actually be used Logical operator or between operator instead.

like operator: fuzzy search on string

Syntax:

xX     like‘要查找的内容"

Common examples and meanings:

name like "%罗%": Represents all data rows with the word "罗" in nam,

name like "Luo%xin: Represents all data rows starting with "Luo" in nam, such as: Roland,

name like "%Luo"; Represents all data rows ending with "Luo" in nam; for example: c Luo, Contra

namelike·Luo_": Represents all data lines in nam that begin with "Luo" and have only 2 characters, such as: Luo Lan

name like·_Luo ": Represents all data lines in nam that end with "Luo" and have only 2 characters, such as: c Luo

A new question:

If I want to find a certain What should I do if the lines containing "%"" in the field? Escape is ok:

%: represents the character % itself

L_: represents the character _ itself. Example ;

xX like "%9i% " ;

represents all lines containing the percent sign (%〉) in XX,

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