MYSQL required to read reading notes Chapter 8 using wildcards for filtering _ MySQL

This article mainly introduces information about using wildcards to filter reading notes for MYSQL. For more information, see Mysql introduction

MySQL is an open-source relational database management system (RDBMS). the MySQL database system uses the most common database management language-Structured Query Language (SQL) for database management.

Tips for using wildcards:

1. do not over-use wildcard characters. If other operators can achieve the same effect as wildcards, other operators should be given priority.

2. do not use wildcards at the beginning of the search mode unless they are absolutely necessary. Place the wildcard at the beginning of the search mode, and the search is the slowest.

3. pay attention to the location of the wildcard. If an error occurs, the expected result may not be returned.

Note:

Case sensitive:Based on the MySQL configuration method, the search can be case sensitive. If case sensitive, 'jet % 'does not match JetPack 1000.

Note:Trailing space may interfere with wildcard matching

Note that although % can match anything, NULL is an exception, that is, NULL. Even where prod_name LIKE '%' cannot match the line with the value NULL as the product name.

% Of the wildcards used match 0 or multiple characters. _ Can only match one character.

The above is what MYSQL must know: Reading Notes Chapter 8 uses wildcards to filter _ MySQL content. For more information, see PHP Chinese network (www.php1.cn )!