大约有 40,000 项符合查询结果（耗时：0.0383秒） [XML]
@UniqueConstraint annotation in Java
...@UniqueConstraint annotation is for annotating multiple unique keys at the table level, which is why you get an error when applying it to a field.
References (JPA TopLink):
@UniqueConstraint
@Column
share
|
...
How to define hash tables in Bash?
...cripting. The most important reason is that eval treats your data as executable code (there are many other reasons too).
First and foremost: Consider upgrading to bash 4. This will make the whole process much easier for you.
If there's a reason you can't upgrade, declare is a far safer option. ...
Unique constraint on multiple columns
...
By using the constraint definition on table creation, you can specify one or multiple constraints that span multiple columns. The syntax, simplified from technet's documentation, is in the form of:
CONSTRAINT constraint_name UNIQUE [ CLUSTERED | NONCLUSTERED ]
...
How to resize superview to fit all subviews with autolayout?
...ork as long as your constraints are correct. If you want to use it on a UITableViewCell (to determine row height for example) then you should call it against your cell contentView and grab the height.
Further considerations exist if you have one or more UILabel's in your view that are multiline....
Access denied for user 'root'@'localhost' while attempting to grant privileges. How do I grant privi
...er_priv: Y
Show_db_priv: Y
Super_priv: Y
Create_tmp_table_priv: Y
Lock_tables_priv: Y
Execute_priv: Y
Repl_slave_priv: Y
Repl_client_priv: Y
Create_view_priv: Y
Show_view_priv: Y
Create_routine_priv: Y
Alter_routine_priv: Y
...
MySQL query String contains
...
Quite simple actually:
mysql_query("
SELECT *
FROM `table`
WHERE `column` LIKE '%{$needle}%'
");
The % is a wildcard for any characters set (none, one or many). Do note that this can get slow on very large datasets so if your database grows you'll need to use fulltext indice...
Python's equivalent of && (logical-and) in an if-statement
...
@Buge it looks like "or" is higher up in the table that you linked
– Matt
Dec 4 '17 at 14:59
5
...
Can PHP PDO Statements accept the table or column name as parameter?
Why can't I pass the table name to a prepared PDO statement?
7 Answers
7
...
How to return result of a SELECT inside a function in PostgreSQL?
...ERY:
CREATE OR REPLACE FUNCTION word_frequency(_max_tokens int)
RETURNS TABLE (txt text -- also visible as OUT parameter inside function
, cnt bigint
, ratio bigint) AS
$func$
BEGIN
RETURN QUERY
SELECT t.txt
, count(*) AS cnt -- co...
Possible to perform cross-database queries with PostgreSQL?
...them.
postgres_fdw
Use postgres_fdw (foreign data wrapper) to connect to tables in any Postgres database - local or remote.
Note that there are foreign data wrappers for other popular data sources. At this time, only postgres_fdw and file_fdw are part of the official Postgres distribution.
For P...