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Difference between HashSet and HashMap?
... functions. This is critical because HashMap uses power-of two length hash tables." weblogs.java.net/blog/2005/06/18/hashmap-implementation - however, if you look at the doc you'll see that this hash distributes things over "buckets", so in the end I believe two things can get mapped the same bucket...
How to drop columns by name in a data frame
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I tried to delete a column while using the package data.table and got an unexpected result. I kind of think the following might be worth posting. Just a little cautionary note.
[ Edited by Matthew ... ]
DF = read.table(text = "
fruit state grade y1980 y1990 y2000
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The Role Manager feature has not been enabled
...thod will run just fine (if you haven't messed elsewhere) and create a few tables in your Database;
Press Ctrl+W+L to open the Server Explorer and you should be able to check in Data Connections > DefaultConnection > Tables the Roles and UsersInRoles tables among the newly created tables!
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Mechanisms for tracking DB schema changes [closed]
...mber of files numbered 1.sql, 2.sql, 3.sql, etc. The script uses one extra table to store the current version number of the database. The N.sql files are crafted by hand, to go from version (N-1) to version N of the database.
They can be used to add tables, add columns, migrate data from an old to ...
How to concatenate text from multiple rows into a single text string in SQL server?
Consider a database table holding names, with three rows:
47 Answers
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How to select distinct rows in a datatable and store into an array
I have a dataset objds. objds contains a table named Table1. Table1 contains column named ProcessName. This ProcessName contains repeated names.So i want to select only distinct names.Is this possible.
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MySQL Query to select data from last week?
Hi I have a table with a date field and some other information.
I want to select all entries from the past week, (week start from Sunday).
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Multiple queries executed in java in single statement
... it is possible to execute something like this using JDBC.
"SELECT FROM * TABLE;INSERT INTO TABLE;"
Yes it is possible. There are two ways, as far as I know. They are
By setting database connection property to allow multiple queries,
separated by a semi-colon by default.
By calling a stored pro...
Use variable with TOP in select statement in SQL Server without making it dynamic [duplicate]
...'s possible to use a variable in the top clause.
select top (@top) * from tablename
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GCC -fPIC option
...DIT: In response to comment.
If your code is compiled with -fPIC, it's suitable for inclusion in a library - the library must be able to be relocated from its preferred location in memory to another address, there could be another already loaded library at the address your library prefers.
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