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How to set a Django model field's default value to a function call / callable (e.g., a date relative
...ow_add=True in the constructor, the datetime referenced by my_date is "immutable" (only set once when the row is inserted to the table).
With auto_now=True, however, the datetime value will be updated every time the object is saved.
This was definitely a gotcha for me at one point. For reference, ...
Datatables - Search Box outside datatable
I'm using DataTables ( datatables.net ) and I would like my search box to be outside of the table (for example in my header div).
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Create an empty data.frame
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You could use read.table with an empty string for the input text as follows:
colClasses = c("Date", "character", "character")
col.names = c("Date", "File", "User")
df <- read.table(text = "",
colClasses = colClasses,
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How do you check if a certain index exists in a table?
....indexes
WHERE name='YourIndexName' AND object_id = OBJECT_ID('Schema.YourTableName')
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Generate sql insert script from excel worksheet
...ge file, but you can use Excel to create insert statements:
="INSERT INTO table_name VALUES('"&A1&"','"&B1&"','"&C1&"')"
In MS SQL you can use:
SET NOCOUNT ON
To forego showing all the '1 row affected' comments. And if you are doing a lot of rows and it errors out, put...
MySQL - length() vs char_length()
... 2 characters, even though like all combining marks it can — if a suitable font is available — be rendered as a single glyph. UTF-16LE can still have a 4-byte character though thanks to the surrogates.
– bobince
Nov 14 '09 at 22:05
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php is null or empty?
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As is shown in the following table, empty($foo) is equivalent to $foo==null and is_null($foo) has the same function of $foo===null. The table also shows some tricky values regarding the null comparison. (ϕ denotes an uninitialized variables. )
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SQLite select where empty?
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It looks like you can simply do:
SELECT * FROM your_table WHERE some_column IS NULL OR some_column = '';
Test case:
CREATE TABLE your_table (id int, some_column varchar(10));
INSERT INTO your_table VALUES (1, NULL);
INSERT INTO your_table VALUES (2, '');
INSERT INTO your_t...
Select values from XML field in SQL Server 2008
...alue('(/person//lastName/node())[1]', 'nvarchar(max)') as LastName
FROM [myTable]
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How to create ENUM type in SQLite?
I need to convert a table from MySQL to SQLite, but I can't figure out how to convert an enum field, because I can't find ENUM type in SQLite.
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