MySQL _在单个查询中检索多个行和列
am new to Mysql 我是Mysql的新手 I want to retrieve all the columns containing StrainName=M18 from the database , but am getting error. please help me in t...
MySQL更新查询“字段列表”错误中的未知列
i echoed the query below: (query is safe) 我回显以下查询:(查询是安全的) UPDATE otelozellik SET isim_tr='test', aciklama_tr='<p>test1</p>', ...
MySQL查询用下划线替换列中的空格
I have a MySQL database table 'photos' with a column 'filename'. I need to replace the spaces in the filename column values with underscores. Is it po...
选择查询获取表中的行作为MySQL中的列
I have a MySQL database with two tables for questions and answers. Each question has a correct answer and three incorrect answers. There are always fo...
mysql在查询结果列表前添加一列递增的序号列(最简)
SELECT @rownum:=@rownum+1 AS 序号, t_user.* FROM t_user ,(SELECT @rownum:=0) r -- 最简写法1更多写法供参考:① select (@rowNO := @rowNo+1) AS rowno,uid,uname from ...
在内部查询中引用外部查询(UPDATE)列会在MySQL上出错
I have a query like the following : 我有如下查询: UPDATE prog_fattSET fat_prg = (SELECT MAX(VALUE) FROM (SELECT 0 AS VALUE ...
MySQL查询用下划线替换列中的空格
I have a MySQL database table 'photos' with a column 'filename'. I need to replace the spaces in the filename column values with underscores. Is it po...
Mysql查询列中的逗号分隔值和搜索关键字中的aslo
I have one condition in query where I want to search results. In database there is region column in which region is saved as comma separated. And user...
MySQL使用select语句查询指定表中指定列(字段)的数据
本文介绍MySQL数据库中执行select查询语句,查询指定列的数据,即指定字段的数据,需要的朋友可以参考下
MySql数据库查询表信息/列信息(列ID/列名/数据类型/长度/精度/是否可以为null/默认值/是否自增/是否是主键/列描述)
查询表信息(表名/表描述):SELECT table_name name,TABLE_COMMENT value FROM INFORMATION_SCHEMA.TABLES WHERE table_type='base table'and table_schema = '数据库名' order ...
如何通过1个查询将一个表的多行组合成Mysql中的多个列?
I have a table that stores values based on two identifying values (product code, and a detail code) that make each row unique and a 3rd value that sto...
在MySQL子查询中选择多个列/字段。
Basically there is attribute table and translation table - many translations for one attribute. 基本上有属性表和转换表——一个属性的多个转换。 I need to select id and value ...
mysql查询为一个列值返回NULL
I have a mysql database where I want to search for rows that satisfy a certain condition. For that, I'm using the LIKE command, until here, all fine. ...
如何使用两个不同的列mySQL从查询中获取数据而不是在其他查询中? [重复]
This question already has an answer here: 这个问题在这里已有答案: Select NOT IN multiple columns 3 answers 选择NOT IN多列3个答案 I tried to do that query bu...
mysql查询获取列中每个元素的计数
i have a table called category in which i have main category ids and names and each main category has sub category ids and names.i also have a product...
【MySql】查询数据库中所有表及列的信息
1 SELECT 2 TABLE_NAME, -- 表名3 COLUMN_NAME, -- 字段名4 DATA_TYPE, -- 字段类型5 COLUMN_COMMENT -- 字段注释6 FROM...
如果在查询中使用order by,如何在MySQL中排序索引列?
I am reading an article about how Pinterest shards their MySQL database: https://medium.com/@Pinterest_Engineering/sharding-pinterest-how-we-scaled-ou...
MySQL - 在查询中替换列中的空格
In a query I'm comparing mobile numbers against another (mobile) value in another column. 在查询中,我将移动数字与另一列中的另一个(移动)值进行比较。 So far I'm doing this by some...
mysql查询结果多列拼接查询
mysql查询结果多列拼接查询,主要场景是,列表中其中一列涉及另外一张表的多条数据,但是我只需要多条数据中的其中某一列(主子表场景) 关键字:GROUP_CONCAT sql语句如下: SELECT r.id,b.NAME AS group_name,GROUP_CONCAT...
计算MYSQL查询的列的平均值。
Ok experts...I've got a table that I am trying to calculate the average of the values in a column. Here is my lookup: 好的专家……我有一个表我要计算列中值的平均值。这是我查找: $g...