MySQL - 布尔全文搜索
MySQL 布尔全文搜索
MySQL 提供了支持三种搜索类型的全文搜索功能,其中一种是布尔全文搜索。
此布尔全文搜索允许使用布尔运算符(例如 +、-、>、<、* 等)和搜索字符串,从而实现对大量文本数据进行复杂的搜索操作。
与搜索概念的自然语言全文搜索不同,MySQL 中的布尔全文搜索查找特定词语。要执行此类搜索,必须在 AGAINST 表达式中包含 IN BOOLEAN MODE 修饰符。
语法
以下是在 MySQL 中使用 IN BOOLEAN MODE 修饰符和 AGAINST 表达式执行布尔全文搜索的语法 -
SELECT column_name(s) FROM table_name WHERE MATCH(target_column_names) AGAINST(expression IN BOOLEAN MODE);
其中,
- target_column_names 是我们要在其中搜索关键字的列名。
- expression 是包含布尔运算符的关键字列表。
MySQL 布尔全文搜索运算符
下表列出了全文搜索布尔运算符 -
运算符 | 描述 |
---|---|
+ | 包含,该词必须是存在。 |
- | 排除,该词不能存在。 |
> | 包含,该词必须存在,且优先级较高。 |
< | 包含,该词必须存在,且优先级较低。 |
() | 将单词分组为子表达式 |
示例
首先,我们使用以下查询创建一个名为 ARTICLES 的表 -
CREATE TABLE ARTICLES ( ID INT AUTO_INCREMENT NOT NULL PRIMARY KEY, ARTICLE_TITLE VARCHAR(100), DESCRIPTION TEXT, FULLTEXT (ARTICLE_TITLE, DESCRIPTION) );
在上述查询中,我们在ARTICLE_TITLE和DESCRIPTION列上定义了全文索引。现在,让我们将值插入到上述创建的表中 -
INSERT INTO ARTICLES (ARTICLE_TITLE, DESCRIPTION) VALUES ('MySQL Tutorial', 'MySQL is a relational database system that uses SQL to structure data stored'), ('Java Tutorial', 'Java is an object-oriented and platform-independent programming languag'), ('Hadoop Tutorial', 'Hadoop is framework that is used to process large sets of data'), ('Big Data Tutorial', 'Big Data refers to data that has wider variety of data sets in larger numbers'), ('JDBC Tutorial', 'JDBC is a Java based technology used for database connectivity');
ARTICLES 表创建如下 -
ID | ARTICLE_TITLE | DESCRIPTION |
---|---|---|
1 | MySQL Tutorial | MySQL is a relational database system that uses SQL to structure data stored |
2 | Java Tutorial | Java is an object-oriented and platform-independent programming language |
3 | Hadoop Tutorial | Hadoop is framework that is used to process large sets of data |
4 | Big Data Tutorial | Big Data refers to data that has wider variety of data sets in larger numbers |
5 | JDBC Tutorial | JDBC is a Java based technology used for database connectivity |
现在,让我们以布尔模式执行全文搜索,搜索包含单词"data"的行 -
SELECT * FROM ARTICLES WHERE MATCH (ARTICLE_TITLE, DEscription) AGAINST('data' IN BOOLEAN MODE);
输出
正如我们在下面的输出中看到的,上述查询返回了三行包含单词"data"的行 -
ID | ARTICLE_TITLE | DESCRIPTION |
---|---|---|
4 | Big Data Tutorial | Big Data refers to data that has wider variety of data sets in larger numbers |
1 | MySQL Tutorial | MySQL is a relational database system that uses SQL to structure data stored |
3 | Hadoop Tutorial | Hadoop is framework that is used to process large sets of data |
示例
在以下查询中,我们搜索包含单词"data"但不包含"sets"的行 -
SELECT * FROM ARTICLES WHERE MATCH(ARTICLE_TITLE, DEscription) AGAINST('+data -sets' IN BOOLEAN MODE);
输出
上述查询的输出如下所示 -
ARTICLE_TITLE | DESCRIPTION |
---|---|
MySQL Tutorial | MySQL is a relational database system that uses SQL to structure data stored |
示例
此处,我们搜索同时包含单词"data"和"set"的行 -
SELECT * FROM ARTICLES WHERE MATCH(ARTICLE_TITLE, DEscription) AGAINST('+data +sets' IN BOOLEAN MODE);
输出
执行给定查询后,输出显示如下 -
ID | ARTICLE_TITLE | DESCRIPTION |
---|---|---|
4 | Big Data Tutorial | Big Data refers to data that has wider variety of data sets in larger numbers |
3 | Hadoop Tutorial | Hadoop is framework that is used to process large sets of data |
示例
在以下查询中,我们搜索包含单词"set"的行,但不搜索包含"set"的行中排名较高的行 -
SELECT * FROM ARTICLES WHERE MATCH(ARTICLE_TITLE, DEscription) AGAINST('+data sets' IN BOOLEAN MODE);
输出
执行上述查询后,输出结果如下 -
ID | ARTICLE_TITLE | DESCRIPTION |
---|---|---|
4 | Big Data Tutorial | Big Data refers to data that has wider variety of data sets in larger numbers |
3 | Hadoop Tutorial | Hadoop is framework that is used to process large sets of data |
1 | MySQL Tutorial | MySQL is a relational database system that uses SQL to structure data stored |
示例
使用以下查询,我们将搜索包含单词"data"的行,如果该记录包含单词"tutorial",则将其排名降低 -
SELECT * FROM ARTICLES WHERE MATCH(ARTICLE_TITLE, DEscription) AGAINST('+data ~sets' IN BOOLEAN MODE);
输出
执行给定查询后,输出显示如下 -
ID | ARTICLE_TITLE | DESCRIPTION |
---|---|---|
4 | Big Data Tutorial | Big Data refers to data that has wider variety of data sets in larger numbers |
1 | MySQL Tutorial | MySQL is a relational database system that uses SQL to structure data stored |
3 | Hadoop Tutorial | Hadoop is framework that is used to process large sets of data |
示例
这里,我们查找所有包含以"set"开头的单词的行 -
SELECT * FROM ARTICLES WHERE MATCH(ARTICLE_TITLE, DEscription) AGAINST('set*' IN BOOLEAN MODE);
输出
执行给定查询后,输出显示如下 -
ID | ARTICLE_TITLE | DESCRIPTION |
---|---|---|
3 | Hadoop Tutorial | Hadoop is framework that is used to process large sets of data |
4 | Big Data Tutorial | Big Data refers to data that has wider variety of data sets in larger numbers |
MySQL 布尔全文搜索功能
以下是 MySQL 布尔全文搜索的一些重要功能 -
- 在布尔全文搜索中,MySQL 不会自动按相关性降序对行进行排序。
- InnoDB 表要求 MATCH 表达式的所有列都具有 FULLTEXT 索引才能执行布尔查询。
- 如果我们在 InnoDB 表的搜索查询中提供多个布尔运算符(例如"++hello"),MySQL 不支持它们并会生成错误。但是,如果我们在 MyISAM 中执行相同的操作,它会忽略额外的运算符并使用最接近搜索词的运算符。
- InnoDB 全文搜索不支持尾随 (+) 或 (-) 符号。它仅支持以 + 或 − 符号开头。
- 如果搜索词是"hello+"或"hello-",MySQL 将生成错误。此外,以下"+*"和"+-"也会产生错误。
- 如果该词出现在超过 50% 的行中,MySQL 将忽略搜索结果中的该词。这称为 50% 阈值。
使用客户端程序进行布尔全文搜索
我们也可以使用客户端程序在 MySQL 数据库上执行布尔全文搜索操作。
语法
要通过 PHP 程序执行布尔全文搜索,我们需要使用 mysqli 函数 query() 执行以下 SELECT 语句,如下所示 -
$sql = "SELECT * FROM Articles WHERE MATCH(ARTICLE_TITLE, Description) AGAINST('+data -sets' IN BOOLEAN MODE)"; $mysqli->query($sql);
要通过 JavaScript 程序执行布尔全文搜索,我们需要使用 mysql2 库的 query() 函数执行以下 SELECT 语句,如下所示 -
sql = `SELECT * FROM Articles WHERE MATCH(ARTICLE_TITLE, Description) AGAINST('+data -sets' IN BOOLEAN MODE)`; con.query(sql);
要通过 Java 程序执行布尔全文搜索,我们需要使用 JDBC 函数 executeQuery() 执行 SELECT 语句,如下所示 -
String sql = "SELECT * FROM Articles WHERE MATCH(ARTICLE_TITLE, DEscription) AGAINST('+data -sets' IN BOOLEAN MODE)"; statement.executeQuery(sql);
要通过 Python 程序执行布尔全文搜索,我们需要使用 MySQL Connector/Python 的 execute() 函数执行 SELECT 语句,如下所示 -
boolean_fulltext_search_query = 'select * from Articles where MATCH (ARTICLE_TITLE, Description) AGAINST('data' IN BOOLEAN MODE)' cursorObj.execute(boolean_fulltext_search_query)
示例
以下是程序 -
$dbhost = 'localhost'; $dbuser = 'root'; $dbpass = 'password'; $dbname = 'TUTORIALS'; $mysqli = new mysqli($dbhost, $dbuser, $dbpass, $dbname); if ($mysqli->connect_errno) { printf("Connect failed: %s
", $mysqli->connect_error); exit(); } // printf('Connected successfully.
'); //creating a table Articles that stores fulltext. $sql = "CREATE TABLE Articles (ID INT AUTO_INCREMENT NOT NULL PRIMARY KEY, ARTICLE_TITLE VARCHAR(100), DESCRIPTION TEXT, FULLTEXT (ARTICLE_TITLE, DESCRIPTION))"; $result = $mysqli->query($sql); if ($result) { printf("Table created successfully...! "); } //insert data $q = "INSERT INTO Articles (ARTICLE_TITLE, DESCRIPTION) VALUES ('MySQL Tutorial', 'MySQL is a relational database system that uses SQL to structure data stored'), ('Java Tutorial', 'Java is an object-oriented and platform-independent programming languag'), ('Hadoop Tutorial', 'Hadoop is framework that is used to process large sets of data'), ('Big Data Tutorial', 'Big Data refers to data that has wider variety of data sets in larger numbers'), ('JDBC Tutorial', 'JDBC is a Java based technology used for database connectivity')"; if ($res = $mysqli->query($q)) { printf("Data inserted successfully...! "); } $s = "SELECT * FROM articles WHERE MATCH(ARTICLE_TITLE, DESCRIPTION) AGAINST('+data -sets' IN BOOLEAN MODE)"; if ($r = $mysqli->query($s)) { printf("Table Records: "); while ($row = $r->fetch_assoc()) { printf(" ID: %d, Title: %s, Descriptions: %s", $row["id"], $row["ARTICLE_TITLE"], $row["DESCRIPTION"]); printf(" "); } } else { printf('Failed'); } $mysqli->close();
输出
获得的输出如下所示 -
Table created successfully...! Data inserted successfully...! Table Records: ID: 1, Title: MySQL Tutorial, Descriptions: MySQL is a relational database system that uses SQL to structure data stored
var mysql = require("mysql2"); var con = mysql.createConnection({ host: "localhost", user: "root", password: "password", }); //连接到 MySQL con.connect(function (err) { if (err) throw err; // console.log("Connected successfully...!"); // console.log("--------------------------"); sql = "USE TUTORIALS"; con.query(sql); sql = "CREATE TABLE Articles (ID INT AUTO_INCREMENT NOT NULL PRIMARY KEY, ARTICLE_TITLE VARCHAR(100), DESCRIPTION TEXT, FULLTEXT (ARTICLE_TITLE, DESCRIPTION) )"; con.query(sql); //insert data into created table sql = `INSERT INTO Articles (ARTICLE_TITLE, DESCRIPTION) VALUES ('MySQL Tutorial', 'MySQL is a relational database system that uses SQL to structure data stored'), ('Java Tutorial', 'Java is an object-oriented and platform-independent programming languag'), ('Hadoop Tutorial', 'Hadoop is framework that is used to process large sets of data'), ('Big Data Tutorial', 'Big Data refers to data that has wider variety of data sets in larger numbers'), ('JDBC Tutorial', 'JDBC is a Java based technology used for database connectivity')`; con.query(sql); //display the table details!... sql = `SELECT * FROM articles WHERE MATCH(ARTICLE_TITLE, DESCRIPTION) AGAINST('+data -sets' IN BOOLEAN MODE)`; con.query(sql, function (err, result) { if (err) throw err; console.log(result); }); });
输出
获得的输出如下所示 -
[ { id: 1, ARTICLE_TITLE: 'MySQL Tutorial', DESCRIPTION: 'MySQL is a relational database system that uses SQL to structure data stored' } ]
import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.Statement; public class BooleanFulltextSearch { public static void main(String[] args) { String url = "jdbc:mysql://localhost:3306/TUTORIALS"; String username = "root"; String password = "password"; try { Class.forName("com.mysql.cj.jdbc.Driver"); Connection connection = DriverManager.getConnection(url, username, password); Statement statement = connection.createStatement(); System.out.println("Connected successfully...!"); //creating a table that takes fulltext column...! String sql = "CREATE TABLE Articles (ID INT AUTO_INCREMENT NOT NULL PRIMARY KEY, ARTICLE_TITLE VARCHAR(100), DESCRIPTION TEXT, FULLTEXT (ARTICLE_TITLE, DESCRIPTION) )"; statement.execute(sql); System.out.println("Table created successfully...!"); //inserting data to the table String insert = "INSERT INTO Articles (ARTICLE_TITLE, DESCRIPTION) VALUES" + "('MySQL Tutorial', 'MySQL is a relational database system that uses SQL to structure data stored')," + "('Java Tutorial', 'Java is an object-oriented and platform-independent programming languag')," + "('Hadoop Tutorial', 'Hadoop is framework that is used to process large sets of data')," + "('Big Data Tutorial', 'Big Data refers to data that has wider variety of data sets in larger numbers')," + "('JDBC Tutorial', 'JDBC is a Java based technology used for database connectivity')"; statement.execute(insert); System.out.println("Data inserted successfully...!"); //displaying the fulltext records in the boolean mode: ResultSet resultSet = statement.executeQuery("SELECT * FROM articles WHERE MATCH(ARTICLE_TITLE, DESCRIPTION) AGAINST('+data -sets' IN BOOLEAN MODE)"); while (resultSet.next()){ System.out.println(resultSet.getString(1)+" "+resultSet.getString(2)+ " "+resultSet.getString(3)); } connection.close(); } catch (Exception e) { System.out.println(e); } } }
输出
获得的输出如下所示 -
Connected successfully...! Table created successfully...! Data inserted successfully...! 1 MySQL Tutorial MySQL is a relational database system that uses SQL to structure data stored
import mysql.connector # 建立连接 connection = mysql.connector.connect( host='localhost', user='root', password='password', database='tut' ) # 创建游标对象 cursorObj = connection.cursor() boolean_fulltext_search_query = f"select * from articles where MATCH (ARTICLE_TITLE, DESCRIPTION) AGAINST('data' IN BOOLEAN MODE)" cursorObj.execute(boolean_fulltext_search_query) # 获取所有结果 results = cursorObj.fetchall() # 显示结果 print("Boolean Fulltext search results:") for row in results: print(row) cursorObj.close() connection.close()
输出
获得的输出如下所示 -
Boolean Fulltext search results: (4, 'Big Data Tutorial', 'Big Data refers to data that has wider variety of data sets in larger numbers') (1, 'MySQL Tutorial', 'MySQL is a relational database system that uses SQL to structure data stored') (3, 'Hadoop Tutorial', 'Hadoop is framework that is used to process large sets of data')