大约有 40,000 项符合查询结果（耗时：0.0417秒） [XML]
Simulate CREATE DATABASE IF NOT EXISTS for PostgreSQL?
I want to create a database which does not exist through JDBC. Unlike MySQL, PostgreSQL does not support create if not exists syntax. What is the best way to accomplish this?
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Semicolons superfluous at the end of a line in shell scripts?
... on terminal or in shell script.
See the below examples:
On terminal:
[root@server test]# ls;pwd;
On shell script:
[root@server test]# cat test4.sh
echo "Current UserName:"
whoami
echo -e "\nCurrent Date:";date;
[root@server test]#
But I am not agree with the comment that & is equi...
How can I get the Typescript compiler to output the compiled js to a different directory?
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I believe that now you can also use the --rootDir flag to pass a common root folder to the transpiler. This avoid having it find a common root folder.
– guzmonne
Nov 12 '15 at 2:15
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Reset AutoIncrement in SQL Server after Delete
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If you're using MySQL, try this:
ALTER TABLE tablename AUTO_INCREMENT = 1
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Find the number of columns in a table
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In MySQL land (tagged in the question)... A MySQL database is equivalent to a schema in ANSI SQL and the table_catalog is always def
– Steve Buzonas
Mar 5 '14 at 18:17
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putting current class as return type annotation [duplicate]
...r type declarations somewhere in the middle of sources...
The problem has roots in recognizing class object before the class was actually defined. That is simply impossible to do in python.
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COUNT(*) vs. COUNT(1) vs. COUNT(pk): which is better? [duplicate]
... are using as well as the type of table in some cases.
For example, using MySQL, count(*) will be fast under a MyISAM table but slow under an InnoDB. Under InnoDB you should use count(1) or count(pk).
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Laravel - Eloquent or Fluent random row
...vel 3:
User::order_by(DB::raw('RAND()'))->get();
Check this article on MySQL random rows. Laravel 5.2 supports this, for older version, there is no better solution then using RAW Queries.
edit 1: As mentioned by Double Gras, orderBy() doesn't allow anything else then ASC or DESC since this chang...
ActiveRecord: List columns in table from console
...console. It will enter the shell of your database, whether it is sqlite or mysql.
Then, you can query the table columns using sql command like:
pragma table_info(your_table);
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Non-recursive depth first search algorithm
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DFS:
list nodes_to_visit = {root};
while( nodes_to_visit isn't empty ) {
currentnode = nodes_to_visit.take_first();
nodes_to_visit.prepend( currentnode.children );
//do something
}
BFS:
list nodes_to_visit = {root};
while( nodes_to_visit isn't ...