大约有 10,100 项符合查询结果（耗时：0.0205秒） [XML]
Postgres and Indexes on Foreign Keys and Primary Keys
...y_cols )
ORDER BY fkoid, attnum
),
fk_cols_list AS (
SELECT fkoid, array_agg(attname) as cols_list
FROM fk_attributes
GROUP BY fkoid
),
index_list AS (
SELECT indexrelid as indexid,
pg_class.relname as indexname,
indrelid,
indkey,
indpred is not nu...
Read String line by line
...stem.getProperty("line.separator"));
This gives you all lines in a handy array.
I don't know about the performance of split. It uses regular expressions.
share
|
improve this answer
|
...
Double Iteration in List Comprehension
...h meaning to me! Suppose you have a text full of sentences and you want an array of words.
# Without list comprehension
list_of_words = []
for sentence in text:
for word in sentence:
list_of_words.append(word)
return list_of_words
I like to think of list comprehension as stretching cod...
Java, List only subdirectories from a directory, not files
... return new File(current, name).isDirectory();
}
});
System.out.println(Arrays.toString(directories));
Update
Comment from the author on this post wanted a faster way, great discussion here:
How to retrieve a list of directories QUICKLY in Java?
Basically:
If you control the file structure...
Find duplicate lines in a file and count how many time each line was duplicated?
...e variable $1 holds the entire contents of column1 and square brackets are array access. So, for each 1st column of line in data file, the node of the array named dups is incremented.
And at the end, we are looping over dups array with num as variable and print the saved numbers first then their nu...
Declaring a custom android UI element using XML
... constructors to call.
private void init(AttributeSet attrs) {
TypedArray a=getContext().obtainStyledAttributes(
attrs,
R.styleable.MyCustomView);
//Use a
Log.i("test",a.getString(
R.styleable.MyCustomView_android_text));
Log.i("test",""+a.getColor(
...
Can we omit parentheses when creating an object using the “new” operator?
...eanings. This comes up when you try to access a member of the result.
new Array.length // fails because Array.length is the number 1, not a constructor
new Array().length // 0
share
|
improve this...
Decode Base64 data in Java
... and decoders, and for using different classes as inputs and outputs (byte arrays, strings, ByteBuffers, java.io streams).
share
|
improve this answer
|
follow
...
How do I copy a hash in Ruby?
...py works for any object that can be marshalled. Most built-in data types (Array, Hash, String, &c.) can be marshalled.
Marshalling is Ruby's name for serialization. With marshalling, the object--with the objects it refers to--is converted to a series of bytes; those bytes are then used to cre...
Queries vs. Filters
...store the binary true/false match per document , something called a bitSet Array is used.
This BitSet array is in memory and this would be used from second time the filter is queried. This way , using bitset array data-structure , we are able to utilize the cached result.
One more point to note he...