Query OK, 0 rows affected (0.21 sec) 1. 2. 3. 4. 5. 6. 分别单独向表worker中插入两条记录: mysql> insert into worker values(null,'jimy'); Query OK, 1 row affected (0.07 sec) mysql> insert into worker values(null,'Tom'); Query OK, 1 row affected (0.05 sec) mysql> select * ...
This query uses a subquery to generate 10 random “id”s and then use a join to select rows by these “id”s. In our test, it runs in 0.44 seconds. Using EXPAIN, we get the following execution plan for the subquery selecting random ids. 1 Using index; Using temporary; Using filesort...
Inner exception MySql.Data.MySqlClient.MySqlException handled at MySql.Data.MySqlClient.MySqlCommand.ExecuteReader: at MySql.Data.MySqlClient.MySqlDataReader.NextResult (MySql.Data, Version=8.0.30.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d) at MySql.Data.MySqlClient.MySqlCommand.ExecuteReader (...
I have an app that pulls random rows from the database, and have found it is incredibly slow and computationally wasteful to get rows using the suggested query style: SELECT * FROM Table WHERE <<conditions>> LIMIT 5 ORDER BY RAND() ...
The results are stored in a new Recordset object if it is a row-returning query. A closed Recordset object will be returned if it is not a row-returning query. 如果返回行[row-returning]查询语句,那么结果将被存储在一个新的记录对象中;如果它不是一个返回行[row-returning]查询语句,那么它将返回...
importmysql.connector connection=mysql.connector.connect(host="localhost",user="yourusername",password="yourpassword",database="mydatabase")cursor=connection.cursor()insert_query="INSERT INTO mytable (name, age, address) VALUES (%s, %s, %s)"cursor.executemany(insert_query,random_data)--执行插入...
mysql>CREATETABLEt(aBIGINT(20)auto_randomPRIMARYKEYCLUSTERED,bVARCHAR(255));Query OK,0rowsaffected,1warning(0.32sec)mysql>insertintot(b)values(a);Query OK,1rowaffected(0.12sec)mysql>insertintot(b)values(b);Query OK,1rowaffected(0.00sec)mysql>insertintot(b)values(c);Query OK,1rowaffected...
一、下载安装打包程序(通过vs2013) 第一步:你的电脑必须装有VS吧,版本可以自己选。 我自己的是VS2013,没有的话就乖乖的去MSDN上去下载,链接地址如下:http://msdn.itellyou.cn/ 如上图所示,选择对应的版本下载,然后安装就行了。 第二步,安装In......
1 row in set (0.00 sec) Now execute the same query again to get another random value mysql> select *from selectRandomRecord order by rand() limit 1; The following is the output +---+---+ | StudentId | StudentName | +---+---+ | 5 | Mike...
Subject Views Written By Posted Random 5s mysql query response time 4012 C P November 09, 2012 11:40AM Sorry, you can't reply to this topic. It has been closed.