大约有 7,000 项符合查询结果（耗时：0.0310秒） [XML]
INSERT … ON DUPLICATE KEY (do nothing)
... uses resources for the second action.
Use INSERT IGNORE ...,
Negative : MySQL will not show any errors if something goes wrong, so you cannot handle the errors. Use it only if you don’t care about the query.
share
...
“use database_name” command in PostgreSQL
...
If I'm not mistaken, databases in MySQL are more akin to schemas in PostgreSQL -- you can switch between those, but DBs in PostgreSQL are a whole different ballgame.
– mpen
May 10 '12 at 3:40
...
How do you do a limit query in JPQL or HQL?
In Hibernate 3, is there a way to do the equivalent of the following MySQL limit in HQL?
14 Answers
...
What is the difference between an ORM and an ODM?
...(Object Document Mapper) deals with documents. Am I right in assuming that mySQL is an example of ORM and MongoDB is a example of ODM?
...
Simplest way to profile a PHP script
... all the data
$select_query = "SELECT * FROM data_table";
$result = mysql_query($select_query);
prof_flag("Retrieve data");
$rows = array();
$found_data=false;
while($r = mysql_fetch_assoc($result))
{
$found_data=true;
$rows[] = $r;
}
prof_flag("Close DB");
...
How long is the SHA256 hash?
...+ salt, but I don't know how long to make my VARCHAR when setting up the MySQL database. What is a good length?
5 Answers...
SQLAlchemy IN clause
...is using raw SQL mode with SQLAlchemy, I use SQLAlchemy 0.9.8, python 2.7, MySQL 5.X, and MySQL-Python as connector, in this case, a tuple is needed. My code listed below:
id_list = [1, 2, 3, 4, 5] # in most case we have an integer list or set
s = text('SELECT id, content FROM myTable WHERE id IN :...
How to switch databases in psql?
In MySQL , I used use database_name;
12 Answers
12
...
SQL Server - inner join when updating [duplicate]
...it works with UDPATE SET FROM JOIN WHERE? Does it depend on the version of mysql?
– Farside
Apr 28 '16 at 12:45
6
...
GUI Tool for PostgreSQL [closed]
...t to know is there any GUI Tool for PostgreSQL just like SQLYog for MySql
2 Answers
...