mysql

Not getting expected results with the query I've in MySQL

由 别来无恙 提交于 2021-02-11 01:58:35
问题 I have the following table structure that has day wise shifts. At only C shift, time is shared by two days. As you can C Shift starts at 20:30 and ends the next's days 06:00 . The Table structure and data as follows create table `machine_shifts` ( `date` date , `shift_start_time` time , `shift_end_time` time , `shift` varchar (60), `updated_on` timestamp ); insert into `machine_shifts` (`date`, `shift_start_time`, `shift_end_time`, `shift`, `updated_on`) values('2010-01-01','06:00:00','14:30

Not getting expected results with the query I've in MySQL

由 百般思念 提交于 2021-02-11 01:57:14
问题 I have the following table structure that has day wise shifts. At only C shift, time is shared by two days. As you can C Shift starts at 20:30 and ends the next's days 06:00 . The Table structure and data as follows create table `machine_shifts` ( `date` date , `shift_start_time` time , `shift_end_time` time , `shift` varchar (60), `updated_on` timestamp ); insert into `machine_shifts` (`date`, `shift_start_time`, `shift_end_time`, `shift`, `updated_on`) values('2010-01-01','06:00:00','14:30

MySQL query to select distinct rows based on date range overlapping

由 江枫思渺然 提交于 2021-02-11 01:34:07
问题 Let's say we have a table (table1) in which we store 4 values (user_id, name, start_date, end_date) table1 ------------------------------------------------ id user_id name start_date end_date ------------------------------------------------ 1 1 john 2016-04-02 2016-04-03 2 2 steve 2016-04-06 2016-04-06 3 3 sarah 2016-04-03 2016-04-03 4 1 john 2016-04-12 2016-04-15 I then enter a start_date of 2016-04-03 and end_date of 2016-04-03 to see if any of the users are available to be scheduled for a

MySQL query to select distinct rows based on date range overlapping

由 放肆的年华 提交于 2021-02-11 01:33:24
问题 Let's say we have a table (table1) in which we store 4 values (user_id, name, start_date, end_date) table1 ------------------------------------------------ id user_id name start_date end_date ------------------------------------------------ 1 1 john 2016-04-02 2016-04-03 2 2 steve 2016-04-06 2016-04-06 3 3 sarah 2016-04-03 2016-04-03 4 1 john 2016-04-12 2016-04-15 I then enter a start_date of 2016-04-03 and end_date of 2016-04-03 to see if any of the users are available to be scheduled for a

MYSQL 5.7 Getting the row number

由 无人久伴 提交于 2021-02-10 23:17:12
问题 I have a database called "playerrank" that has points column. I want to show on people's profile page their rank like this: Rank: 3/1456 I tried using ROW_NUMBER() but it seems like my host has low version (5.7 i believe).its giving me errors. Is there another way i can get the ranking of a player based on points other than ordering the db by points desc and getting the row number somehow? 回答1: One option to simulate row number in MySQL 5.7 uses session variables: SET @row_number = 0; SELECT

MYSQL 5.7 Getting the row number

由 瘦欲@ 提交于 2021-02-10 23:16:31
问题 I have a database called "playerrank" that has points column. I want to show on people's profile page their rank like this: Rank: 3/1456 I tried using ROW_NUMBER() but it seems like my host has low version (5.7 i believe).its giving me errors. Is there another way i can get the ranking of a player based on points other than ordering the db by points desc and getting the row number somehow? 回答1: One option to simulate row number in MySQL 5.7 uses session variables: SET @row_number = 0; SELECT

MYSQL 5.7 Getting the row number

由 霸气de小男生 提交于 2021-02-10 23:16:22
问题 I have a database called "playerrank" that has points column. I want to show on people's profile page their rank like this: Rank: 3/1456 I tried using ROW_NUMBER() but it seems like my host has low version (5.7 i believe).its giving me errors. Is there another way i can get the ranking of a player based on points other than ordering the db by points desc and getting the row number somehow? 回答1: One option to simulate row number in MySQL 5.7 uses session variables: SET @row_number = 0; SELECT

MYSQL 5.7 Getting the row number

由 放肆的年华 提交于 2021-02-10 23:14:35
问题 I have a database called "playerrank" that has points column. I want to show on people's profile page their rank like this: Rank: 3/1456 I tried using ROW_NUMBER() but it seems like my host has low version (5.7 i believe).its giving me errors. Is there another way i can get the ranking of a player based on points other than ordering the db by points desc and getting the row number somehow? 回答1: One option to simulate row number in MySQL 5.7 uses session variables: SET @row_number = 0; SELECT

MYSQL 5.7 Getting the row number

由 烈酒焚心 提交于 2021-02-10 23:10:43
问题 I have a database called "playerrank" that has points column. I want to show on people's profile page their rank like this: Rank: 3/1456 I tried using ROW_NUMBER() but it seems like my host has low version (5.7 i believe).its giving me errors. Is there another way i can get the ranking of a player based on points other than ordering the db by points desc and getting the row number somehow? 回答1: One option to simulate row number in MySQL 5.7 uses session variables: SET @row_number = 0; SELECT

mysql 单表查询、多表查询

由 ╄→尐↘猪︶ㄣ 提交于 2021-02-10 23:01:44
首先我说一下关于查询的顺序和一些查询的方法 select * as 别名 from 表名 where 条件 group by 字段名 hanving 条件 order by 字段名 （asc/desc） 执行这条命令的顺序 是先从from 开始 获得哪张表，然后在开始判断条件，进行分组having 二次判断，用在group by 分组后面，然后 order by 字段名，根据字段名进行一个排序，默认为升序。字段名后面可以跟（asc/desc）asc升序，desc降序 最后一步是 select 出所需要的信息。 单表查询 首先....单表查询咱得有一张表 创建下面这张表，我用几个案列来搞定这个单表查询 create table emp( id int not null unique auto_increment, name varchar ( 20 ) not null , sex enum( ' male ' , ' female ' ) not null default ' male ' , #大部分是男的 age int ( 3 ) unsigned not null default 28 , hire_date date not null , post varchar ( 50 ), post_comment varchar ( 100 ), salary double (
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