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List tables in a PostgreSQL schema
...
You can select the tables from information_schema
SELECT * FROM information_schema.tables
WHERE table_schema = 'public'
share
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Data structure: insert, remove, contains, get random element, all at O(1)
...o other solutions).
The requirement that's tricky is the "random element" selection: in a hash table, you would need to scan or probe for such an element.
For closed hashing / open addressing, the chance of any given bucket being occupied is size() / capacity(), but crucially this is typically kep...
How do I connect to a MySQL Database in Python?
...ueries you need
cur = db.cursor()
# Use all the SQL you like
cur.execute("SELECT * FROM YOUR_TABLE_NAME")
# print all the first cell of all the rows
for row in cur.fetchall():
print row[0]
db.close()
Of course, there are thousand of possibilities and options; this is a very basic example. Y...
App Inventor 2 SQLite 拓展：超流行兼容主流SQL语法的迷你本地数据库引擎 ...
...允许您修改数据库以使其兼容。
此设置会影响各种 Select 方法返回结果行的方式。
当此属性为 false 时，Select 方法返回的列表中的每个元素将是一个简单的值列表，这些值表示为每个匹配行选择的列的值。
当此属性为 true ...
How to list the tables in a SQLite database file that was opened with ATTACH?
...quently, if you used
ATTACH some_file.db AS my_db;
then you need to do
SELECT name FROM my_db.sqlite_master WHERE type='table';
Note that temporary tables don't show up with .tables either: you have to list sqlite_temp_master for that:
SELECT name FROM sqlite_temp_master WHERE type='table';
...
What's the Linq to SQL equivalent to TOP or LIMIT/OFFSET?
...
In VB:
from m in MyTable
take 10
select m.Foo
This assumes that MyTable implements IQueryable. You may have to access that through a DataContext or some other provider.
It also assumes that Foo is a column in MyTable that gets mapped to a property name.
...
How do I add a foreign key to an existing SQLite table?
...n step 8 below. One way to
do this is to run a query like the following: SELECT type, sql FROM
sqlite_master WHERE tbl_name='X'.
Use CREATE TABLE to construct a new table "new_X" that is in the
desired revised format of table X. Make sure that the name "new_X"
does not collide with any exi...
Can the jQuery UI Datepicker be made to disable Saturdays and Sundays (and holidays)?
... array with [0] equal to true/false indicating whether or not this date is selectable and 1 equal to a CSS class name(s) or '' for the default presentation. It is called for each day in the datepicker before is it displayed.
Display some national holidays in the datepicker.
$(".selector").datepick...
Can CSS detect the number of children an element has?
...i:first-child:nth-last-child(4) ~ li {
width: 25%;
}
The trick is to select the first child when it's also the nth-from-the-last child. This effectively selects based on the number of siblings.
Credit for this technique goes to André Luís (discovered) & Lea Verou (refined).
Don't you j...
Setting the selected value on a Django forms.ChoiceField
...t hand, but this Q/A comes up for searches related to trying to assign the selected value to a ChoiceField.
If you have already called super().__init__ in your Form class, you should update the form.initial dictionary, not the field.initial property. If you study form.initial (e.g. print self.init...