对于 SET值,强制转换操作将导致使用数值。 通常,您SET使用FIND_IN_SET()函数或 LIKE运算符搜索值 : mysql>SELECT * FROM tbl_name WHERE FIND_IN_SET('value',set_col)>0; mysql>SELECT * FROM tbl_name WHERE set_col LIKE '%value%'; 第一条语句查找set_col包含 valueset成员的行 。第二个相似,但...
Would return the count in less than a second. So far so good. So I added a new column to the main database with the ‘cats’ column, containing the same info I had in the set_test table. To my surprise: Select count(id) from my_table where cats&1; Would take over 6 secs...
MySQL storesSETvalues numerically, with the low-order bit of the stored value corresponding to the first set member. If you retrieve aSETvalue in a numeric context, the value retrieved has bits set corresponding to the set members that make up the column value. For example, you can retrieve...
MySQL connection id is 59 Server version: 8.0.27- MySQL Enterprise Server - Commercial No default schema selected; type \use <schema> to set one. <Classic:icadmin@127.0.0.13310> Inthis example: ic@127.0.0.1:3310 is the URI-like connection string for any member server instance ...
mysql>SELECT*FROMtbl_nameWHEREFIND_IN_SET('value',set_col)>0;mysql>SELECT*FROMtbl_nameWHEREset_colLIKE'%value%'; The first statement finds rows whereset_colcontains thevalueset member. The second is similar, but not the same: It finds rows whereset_colcontainsvalueanywhere, even as a su...
MySQL手册中find_in_set函数的语法解释: FIND_IN_SET(str,strlist) str 要查询的字符串 strlist 字段名 参数以”,”分隔 如 (1,2,6,8,10,22) 查询字段(strlist)中包含(str)的结果,返回结果为null或记录 假如字符串str
1 row in set (0.00 sec) 测试第二个枚举类型字段未插入数据的情况下,是否能使用上字段定义中指定的默认值: root@localhost : test 11:23:17> INSERT INTO mysqlops_enum(ID,Job_type) VALUES(6,‘DBA’); Query OK, 1 row affected (0.00 sec) ...
通过上面的图,不难看出,MySQL Shell是运维人员管理底层MySQL节点的入口,也就是DBA执行管理命令的地方,而MySQL Router是应用程序连接的入口,它的存在,让底层的架构对应用程序透明,应用程序只需要连接MySQL Router就可以和底层的数据库打交道,而数据库的主从架构,都是记录在MySQL Router的原信息里面的。
# Bootstrapping MySQL Router instance at'/data1/yazhou5/mysql/mysql-router'...Please enter MySQL passwordforrouterfriend:# 这里创建新的account账号的密码-Creatingaccount(s)-Verifyingaccount(using it to runSQLqueries that would be run by Router)-Storing accountinkeyring-Adjusting permissionsofgenerate...
mysql find_in_set 索引优化,写在前面:索引对查询的速度有着至关重要的影响,理解索引也是进行数据库性能调优的起点。考虑如下情况,假设数据库中一个表有10^6条记录,DBMS的页面大小为4K,并存储100条记录。如果没有索引,查询将对整个表进行扫描,最坏的情况下,如果所