mysql数据库全局搜索

-- 创建全文索引示例
ALTER TABLE articles ADD FULLTEXT(title, content);

-- 使用全文索引进行搜索
SELECT * FROM articles WHERE MATCH(title, content) AGAINST('keyword');

-- 精确搜索示例
SELECT * FROM users WHERE username = 'exact_username';

-- 存储过程示例
DELIMITER //
CREATE PROCEDURE search_across_databases(IN keyword VARCHAR(255))
BEGIN
    DECLARE done INT DEFAULT FALSE;
    DECLARE db_name VARCHAR(255);
    DECLARE cur CURSOR FOR SELECT DATABASE();
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;

    OPEN cur;

    read_loop: LOOP
        FETCH cur INTO db_name;
        IF done THEN
            LEAVE read_loop;
        END IF;
        SET @sql = CONCAT('SELECT * FROM ', db_name, '.table_name WHERE MATCH(field) AGAINST(''', keyword, ''')');
        PREPARE stmt FROM @sql;
        EXECUTE stmt;
        DEALLOCATE PREPARE stmt;
    END LOOP;

    CLOSE cur;
END //
DELIMITER ;