Database iterative sql syntax

problem description

to get data for all semester weeks, use SQL syntax

the environmental background of the problems and what methods you have tried

related codes

4 attributes, academic year semester, start time, end time, start week, end week

what result do you expect? What is the error message actually seen?

want all dates in 1-23 weeks, such as
2017-2018-1 2018-3-31 2018-4-06 1
2017-2018-1 2018-4-06 2018-4-13 2
2017-2018-1 2018-4-13 2018-4-20 3
2017-2018-1 2018-4-20 2018-4-27 4
2017-2018-1 2018-4-27 2018-5-35
.
2017-2018

different database solutions are fine. I have tried to use tmp table to add sequences and carry out internal association.
but I don"t want to use ordinal lists

Mysql sql

Apr.12,2021

can be solved by stored procedures and executed in a loop

SELECT Term, BeginDate, DATE_ADD (current date, INTERVAL 7 DAY), current number of weeks FROM term_info
current date = DATE_ADD (current date, INTERVAL 7 DAY)
current number of weeks + 1

results are saved to temporary table

Previous: How to solve the problem that Wechat's built-in browser does not support onclick?

Next: Php-fpm error: No pool defined. At least one pool section

SQL statement, JOIN multiple table join table query problem
subject table, which can be understood as a classification table. The course and source_book tables are associated with subject now use the subject table as the main table to query how many courses and books are under this category. query statemen...

Mysql sql

Feb.26,2021
On the Database query Optimization of java programmers in interview
background: 1. I am a java programmer 2. Recently interviewed for a senior development position 3. The previous project mainly used less oracle,mysql, and the companies interviewed basically used mysql s 4. I am weak in the database 5. Recently, I...

Oracle mysql sql java

Feb.27,2021
Is it convenient to modify data items when there is a lot of data in the mysql enum type?
for example, if the database has a field type of enum ( axiomagementific database ), can you change this field to enum when there are millions of data in the database? will it be slow? ...

Mysql sql

Feb.28,2021
Can update operate in batches like insert in sql database?
because batch update operations are always involved recently, I don t know if batch operations can be performed, so we can only update, one by one in the loop , so I d like to ask whether there is a sql statement in the sql database that enables updat...

Insert update mysql sql postgresql

Feb.28,2021
JAVA inserts MySQL data exception
jav inserts Mysql data exception Data too long exception information 2018-04-24 00:15:01 ERROR com.comall.cybershop.common.base.DaoSupport org.springframework.dao.DataIntegrityViolationException: PreparedStatementCallback; SQL [update cs_awardCardRe...

Java mysql sql

Mar.05,2021
Ask for sql sentence?
the Buy, attribute of the data table is the product product, department department, time time, so how to write the sql statement "products purchased by the sales department in 2014 but not purchased by other departments ", I have been thinking about it ...

Mysql sql

Mar.05,2021
Why is there no response to the query of workbench?
after entering the query statement, I kept turning and turning, but there was no response. Please see why http: www.nbjinshi.com bug.png. This is a screenshot. I couldn t upload the screenshot, so I had to upload it to my server ....

Mysql sql

Mar.07,2021
How mysql marks the number of repetitions of a field value
has a table, table_x, field A has a duplicate value: now you want to return the result of the sample diagram through the select query, counting the number of times the value of the corresponding field An is repeated. The ideal effect is shown in figur...

Mysql sql

Mar.09,2021
Ask for a SQL statement
Name Class Score Zhang San Chinese 81 Zhang San Mathematics 75 Li Si Chinese 76 Li Si Mathematics 90 Wang Wu Chinese 81 Wang Wu Mathematics 100 Wang Wu English 90 use a SQL sentence to query the Name of the students with the lowest Chinese sco...

Mysql sql

Mar.11,2021
Can anyone share the advanced experience of sql sentences?
is there any way? such as recommended books, blogs, etc. ...

Sqlserver oracle mysql sql

Mar.11,2021
How to write the sql statement?
means there is no train of thought at all. if user An is only in the R & D group and id is 5, then the number after user An is 32 . How should I write this sentence? There is no external network. I don t know if I can see the pictures taken by pri...

Python java c mysql sql

Mar.12,2021
What is wrong with this section of sql and how to solve it?
(SELECT * FROM `dozhan_reply` t1 WHERE `reply_parent` IN ( SELECT `reply_id` FROM ( SELECT `reply_id` FROM `dozhan_reply` WHERE `reply_article` = 69 AND `reply_type` = 0 LIMIT 0, 5 ) t )) UNION (SEL...

Mysql sql oracle

Mar.12,2021
Solving sql Association query
SELECT * FROM `table_1` WHERE `reply_parent` IN (SELECT `reply_id` FROM (SELECT `reply_id` FROM `table_1` WHERE `reply_article`=69 AND `reply_type`=0 LIMIT 0, 5)AS t) UNION (SELECT * FR...

Mysql sql oracle nosql redis

Mar.12,2021
I would like to ask you that the main table is associated with the child table, and the child table has multiple records, but you only want to get the latest record of the child table (that is, the newly added record).
can you give me a column? ...

Mysql sql

Mar.13,2021
Sql examination questions, how to write, ask for advice!
is like this, and the ultimate effect is to match the avatar address of the drink in the user table for each comment list first, query out the table_1 (article comment table) article comment result set then I found that these comments do not have...

Mysql sql oracle

Mar.13,2021
How to implement like multiple wildcard characters in sql?
there is a problem. What should I do if I want to take a record that matches multiple characters in a field? select * from actor where last_name like ( % DAVI% , MOSTEL% , ABC , kkk%aa ) the above sql statement is incorrect. Like does not sup...

Oracle mysql sql

Mar.14,2021
How to use sqlalchemy to connect to a pymysql database with two tables, extract the data and page it?
these are the data of my two tables: flask: sqlalchemy: : ...

Mysql sqlalchemy flask python

Mar.14,2021
Is there any difference in the efficiency of the two SQL?
there seems to be no difference between the two SQL implementations. select * from A left join B on A.aid=B.aid where A.aid=100 select * from ( select * from A where A.aid=100 ) AA left join B on AA.aid=B.aid what do you think of SQL performing ...

Mysql sql

Mar.14,2021
Is it feasible to delete and then insert when updating database tables?
is it feasible to delete and then insert when updating database tables? the contents of the table are many-to-many relationships ...

Mysql sql

Mar.16,2021
The problem of sql Multi-table query
1. If you use select * from APowerB without any conditions, the result will be displayed associated with tables an and b, but the result will be repeated many times 2, and select * from a join b, will not add any query conditions, and the result will b...

Oracle mysql sql

Mar.18,2021

MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1b36288-3439f.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1b36288-3439f.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
Need Help?