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Best way to check if a Data Table has a null value in it
what is the best way to check if a Data Table has a null value in it ?
6 Answers
6
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Find all records which have a count of an association greater than zero
...s a matter of preference. The count can be done with any field in the join table that is guaranteed to have a value in every row. Most meaningful candidates are projects.id, project_id, and vacancies.id. I chose to count project_id because it is the field on which the join is made; the spine of the ...
How to make CSS width to fill parent?
...ose three different elements all have different rendering rules.
So for:
table#bar you need to set the width to 100% otherwise it will be only be as wide as it determines it needs to be. However, if the table rows total width is greater than the width of bar it will expand to its needed width. IF ...
Test if lists share any items in python
...as such:
bool(set(a) & set(b))
Because sets are stored using a hash table in Python, searching them is O(1) (see here for more information about complexity of operators in Python). Theoretically, this is O(n+m) on average for n and m objects in lists a and b. But 1) it must first create sets ...
How to rename items in values() in Django?
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-1 because .values(supports__through_tables) and this hack doesn't (incidentally probably the most obvious use case for wanting to rename the ValuesQuerySet dict keys)
– wim
Aug 21 '14 at 13:12
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SQL - Update multiple records in one query
I have table - config .
Schema:
config_name | config_value
9 Answers
9
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How to delete a row by reference in data.table?
My question is related to assignment by reference versus copying in data.table . I want to know if one can delete rows by reference, similar to
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Compile time string hashing
... GCC and not MSVC nor Intel compiler.
Here is the code snippet:
// CRC32 Table (zlib polynomial)
static constexpr uint32_t crc_table[256] = {
0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
0xe0d5e91eL, 0...
How to write lists inside a markdown table?
Can one create a list (bullets, numbered or not) inside a markdown table.
6 Answers
6
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SQLite - UPSERT *not* INSERT or REPLACE
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Assuming three columns in the table: ID, NAME, ROLE
BAD: This will insert or replace all columns with new values for ID=1:
INSERT OR REPLACE INTO Employee (id, name, role)
VALUES (1, 'John Foo', 'CEO');
BAD: This will insert or replace 2 of the...