大约有 40,000 项符合查询结果（耗时：0.0445秒） [XML]
Original purpose of ? [closed]
...$_POST['delete_action'])) {
mysqli_query($connection, "DELETE FROM table_name
WHERE record_id = ".$_POST['row_to_be_deleted']);
//Here is where hidden field value is used
}
while(condition) {
?>
<span&g...
How do I break a string over multiple lines?
... "this is my very very \"very\" long string, isn't it."
Summary
In this table, _ means space character. \n means "newline character" (\n in JavaScript), except for the "in-line newlines" row, where it means literally a backslash and an n).
> | " ' &...
Auto margins don't center image in page
...d for margin:auto to center an item in the flow. (display:block or display:table, position:static or position:relative, etc.)
– Phrogz
Apr 20 '11 at 17:26
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How do I generate random number for each row in a TSQL Select?
I need a different random number for each row in my table. The following seemingly obvious code uses the same random value for each row.
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#1071 - Specified key was too long; max key length is 767 bytes
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767 bytes is the stated prefix limitation for InnoDB tables in MySQL version 5.6 (and prior versions). It's 1,000 bytes long for MyISAM tables. In MySQL version 5.7 and upwards this limit has been increased to 3072 bytes.
You also have to be aware that if you set an index on a...
JPA EntityManager: Why use persist() over merge()?
...nate Session (a.k.a Persistence Context) and is not mapped to any database table row is considered to be in the New (Transient) state.
To become persisted we need to either explicitly call the EntityManager#persist method or make use of the transitive persistence mechanism.
Persistent (Managed)
A...
How do I put an already-running process under nohup?
... [-h] [jobspec ...]
Without options, each jobspec is removed from the table of active jobs. If the -h option is given, each jobspec is not
removed from the table, but is marked so that SIGHUP is not sent to the job if the shell receives a SIGHUP. If no jobspec is
present, and neither the -a...
How to choose the id generation strategy when using JPA and Hibernate
...that are unique only when no other process is inserting data into the same table. Do not use in a cluster.
identity
supports identity columns in DB2, MySQL, MS SQL Server, Sybase and HypersonicSQL. The returned identifier is of type long, short or int.
sequence
uses a sequence in DB2, PostgreSQL, Or...
SQL WHERE condition is not equal to?
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You can do like this
DELETE FROM table WHERE id NOT IN ( 2 )
OR
DELETE FROM table WHERE id <> 2
As @Frank Schmitt noted, you might want to be careful about the NULL values too. If you want to delete everything which is not 2(including the NULLs...
How do I check if a column is empty or null in MySQL?
I have a column in a table which might contain null or empty values. How do I check if a column is empty or null in the rows present in a table?
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