A brief explanation of SQL wildcard related knowledge

You can use the SQL wildcard character when searching for data in a database, and this article will explain its knowledge.

You can use SQL wildcard characters when searching for data in a database.

SQL wildcard characters

The SQL wildcard can override one or more characters when searching for data in a database.

SQL wildcard characters must be used with the LIKE operator.

In SQL, you can use the following wildcard characters:

Use a% wildcard character

Example 1

Now, we want to choose from the "Persons" table above for people living in cities that start with "Ne":

We can use the following SELECT statement:

SELECT * from Personswhere city like ' ne% '

Example 2

Next, we want to select from the "Persons" table the people who live in cities that contain "Lond":

We can use the following SELECT statement:

SELECT * from Personswhere city like '%lond% '

Using _ Wildcard characters

Example 1

Now, we want to select the first character of the name from the "Persons" table above and then the person who is "eorge":

We can use the following SELECT statement:

SELECT * from Personswhere FirstName like ' _eorge '

Example 2

Next, we want the last name of the record selected from the "Persons" table to start with "C", then an arbitrary character, then "R", then any character, then "ER":

We can use the following SELECT statement:

SELECT * from Personswhere LastName like ' c_r_er '

Using [charlist] wildcard characters

Example 1

Now, we would like to select from the "Persons" table above the person who lives in the city that begins with "A" or "L" or "N":

We can use the following SELECT statement:

SELECT * from Personswhere city like ' [aln]% '

Example 2

Now, we want to select from the "Persons" table above the people who live in cities that do not start with "A" or "L" or "N":

We can use the following SELECT statement:

SELECT * from Personswhere city like ' [! aln]% '

This article on the wildcard is related to the explanation, more learning materials to pay attention to the PHP Chinese network can be viewed.