The meaning of asterisk in mysql

The asterisk (*) is a wildcard character in MySQL and has the following meanings: Select all columns: In a SELECT statement, it selects all columns from the specified table. Match any sequence of characters: In the WHERE clause, it is used to match any sequence of characters, such as finding rows containing "John". Fuzzy queries: It can also be used for fuzzy queries, such as finding rows starting with "Jo".

The meaning of asterisk (*) in MySQL

The asterisk (*) is a wildcard character in MySQL, used to match any sequence of characters.

Detailed description:

• Select all columns: In the SELECT statement, use the asterisk to select all columns from the specified table . For example:

SELECT * FROM table_name;

• Matches any sequence of characters: In the WHERE clause, use an asterisk to match any sequence of characters. For example, the following query finds all rows that contain "John" in the name column:

SELECT * FROM table_name WHERE name LIKE '%John%';

• Fuzzy queries: The asterisk can also be used for fuzzy queries. For example, the following query finds all rows that begin with "Jo" in the name column:

SELECT * FROM table_name WHERE name LIKE 'Jo%';

Example:

Suppose there is a table named customers, It contains the following columns:

• id
• name
• address
• phone

The following query uses asterisks Select all columns from the customers table:

SELECT * FROM customers;

The following query finds all rows that contain "Smith" in the name column:

SELECT * FROM customers WHERE name LIKE '%Smith%';

The following query finds all rows that begin with "123" in the address column :

SELECT * FROM customers WHERE address LIKE '123%';

The above is the detailed content of The meaning of asterisk in mysql. For more information, please follow other related articles on the PHP Chinese website!