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Reset Entity-Framework Migrations
...e the migrations folder in your project; And
Delete the __MigrationHistory table in your database (may be under system tables); Then
Run the following command in the Package Manager Console:
Enable-Migrations -EnableAutomaticMigrations -Force
Use with or without -EnableAutomaticMigrations
And fin...
Deleting rows with MySQL LEFT JOIN
I have two tables, one for job deadlines, one for describe a job. Each job can take a status and some statuses means the jobs' deadlines must be deleted from the other table.
...
Quickly find whether a value is present in a C array?
... i, j, k, ... as needed, with left or right shifts)
Then you make a fixed table of n entries, where the hash maps the input values to an index i into the table. For valid values, table entry i contains the valid value. For all other table entries, ensure that each entry of index i contains some oth...
Primary key or Unique index?
...e two equal values in that column in two different rows. Example:
CREATE TABLE table1 (foo int, bar int);
CREATE UNIQUE INDEX ux_table1_foo ON table1(foo); -- Create unique index on foo.
INSERT INTO table1 (foo, bar) VALUES (1, 2); -- OK
INSERT INTO table1 (foo, bar) VALUES (2, 2); -- OK
INSERT ...
Quickly reading very large tables as dataframes
I have very large tables (30 million rows) that I would like to load as a dataframes in R. read.table() has a lot of convenient features, but it seems like there is a lot of logic in the implementation that would slow things down. In my case, I am assuming I know the types of the columns ahead o...
How to count the number of set bits in a 32-bit integer?
...rocoded loop that tests a bit per cycle (citation needed).
A pre-populated table lookup method can be very fast if your CPU has a large cache and/or you are doing lots of these instructions in a tight loop. However it can suffer because of the expense of a 'cache miss', where the CPU has to fetch so...
How to copy from CSV file to PostgreSQL table with headers in CSV file?
I want to copy a CSV file to a Postgres table. There are about 100 columns in this table, so I do not want to rewrite them if I don't have to.
...
Copy data into another table
How to copy/append data from one table into another table with same schema in SQL Server?
9 Answers
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中文网（自研/维护）拓展 · App Inventor 2 中文网
...otherwise.
DatabasePath()
Returns the path to the database.
Delete(table,whereClause,bindParams)
Executes a SQL DELETE statement.
DeleteAsync(tag,table,whereClause,bindParams)
Executes a SQL DELETE statement, asynchronously.
DeleteDatabase()
Delete the database.
Execute(sql,bi...
How can I list all foreign keys referencing a given table in SQL Server?
I need to remove a highly referenced table in a SQL Server database. How can I get a list of all the foreign key constraints I will need to remove in order to drop the table?
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