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Select row with most recent date per user
I have a table ("lms_attendance") of users' check-in and out times that looks like this:
11 Answers
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Many-to-many relationship with the same model in rails?
...dditional information with the association? (Additional fields in the join table.)
Do the associations need to be implicitly bi-directional?
(If post A is connected to post B, then post B is also connected to post A.)
That leaves four different possibilities. I'll walk over these below.
For refer...
Import SQL file into mysql
I have a database called nitm . I haven't created any tables there. But I have a SQL file which contains all the necessary data for the database. The file is nitm.sql which is in C:\ drive . This file has size of about 103 MB. I am using wamp server.
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Postgres: clear entire database before re-creating / re-populating from bash script
...g_dump and pg_restore directly together over a pipe.
To drop and recreate tables, you could use the --clean command-line option for pg_dump to emit SQL commands to clean (drop) database objects prior to (the commands for) creating them. (This will not drop the whole database, just each table/sequen...
How do I use ROW_NUMBER()?
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For the first question, why not just use?
SELECT COUNT(*) FROM myTable
to get the count.
And for the second question, the primary key of the row is what should be used to identify a particular row. Don't try and use the row number for that.
If you returned Row_Number() in your main...
Why does C++11 not support designated initializer lists as C99? [closed]
...me it has failed
Ben Voigt's comments have helped me to see the insurmountable problems with this approach; given:
struct X {
int c;
char a;
float b;
};
What order would these functions be called in in c99: struct X foo = {.a = (char)f(), .b = g(), .c = h()}? Surprisingly, in c99:
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创建增量同步Oracle物化视图问题 - 数据库(内核) - 清泛网 - 专注C/C++及内核技术
...个表上建立物化视图日志如“CREATE MATERIALIZED VIEW LOG ON T_tablename;”，再到数据库B上创建数据库链接和快速刷新的物化视图如“create materialized view mv_tablename refresh fast on demand start with sysdate next sysdate+1/288 as select * from T_tablename@dblink_...
Why can't C compilers rearrange struct members to eliminate alignment padding? [duplicate]
...it (for example: a foreign library, a file on disc, network data, CPU page tables, ...). In such a case the binary structure of data is also defined in a place inaccessible to the compiler, so reordering the struct fields would create a data type that is inconsistent with the other definitions. For ...
Reliable method to get machine's MAC address in C#
...d be many active connections on a machine and their order may not be predictable.
– Dave R.
Mar 9 '11 at 15:33
@DaveR....
How to dump a table to console?
I'm having trouble displaying the contents of a table which contains nested tables (n-deep). I'd like to just dump it to std out or the console via a print statement or something quick and dirty but I can't figure out how. I'm looking for the rough equivalent that I'd get when printing an NSDicti...