大约有 40,000 项符合查询结果（耗时：0.0240秒） [XML]
In JavaScript, why is “0” equal to false, but when tested by 'if' it is not false by itself?
...
Tables displaying the issue:
and ==
Moral of the story use ===
table generation credit: https://github.com/dorey/JavaScript-Equality-Table
sha...
SQL Server indexes - ascending or descending, what difference does it make?
...rily matters when used with composite indexes:
CREATE INDEX ix_index ON mytable (col1, col2 DESC);
can be used for either:
SELECT *
FROM mytable
ORDER BY
col1, col2 DESC
or:
SELECT *
FROM mytable
ORDER BY
col1 DESC, col2
, but not for:
SELECT *
FROM mytable
ORDE...
Table Header Views in StoryBoards
Is there a way to insert a Table Header View (tableHeaderView) in StoryBoard (like we used to do in Interface Builder)?
3 A...
UICollectionView inside a UITableViewCell — dynamic height?
...plication screens requires us to place a UICollectionView inside of a UITableViewCell . This UICollectionView will have a dynamic number of items, resulting in a height which must be calculated dynamically as well. However, I am running into problems trying to calculate the height of the embe...
How can I get column names from a table in Oracle?
...he database to get the column names , not to be confused with data in the table. For example, if I have a table named EVENT_LOG that contains eventID , eventType , eventDesc , and eventTime , then I would want to retrieve those field names from the query and nothing else.
...
How to generate a create table script for an existing table in phpmyadmin?
How can I generate a create table script for an existing table in phpmyadmin?
10 Answers
...
PostgreSQL: insert from another table
I'm trying to insert data to a table from another table and the tables have only one column in common. The problem is, that the TABLE1 has columns that won't accept null values so I can't leave them empty and I can't get them from the TABLE2.
...
How do you set a default value for a MySQL Datetime column?
...that with DATETIME...
But you can do it with TIMESTAMP:
mysql> create table test (str varchar(32), ts TIMESTAMP DEFAULT CURRENT_TIMESTAMP);
Query OK, 0 rows affected (0.00 sec)
mysql> desc test;
+-------+-------------+------+-----+-------------------+-------+
| Field | Type | Null | ...
常用Sql - 数据库(内核) - 清泛网 - 专注C/C++及内核技术
常用Sqlmysql：drop table if exists tablename;不能写成drop table tablename if exists tablename;mysql：建立索引SqlCREATE TABLE t...mysql：drop table if exists tablename;
不能写成
drop table tablename if exists tablename;
mysql：建立索引Sql
CREATE TABLE tablename (
`ID...
How to rename a table in SQL Server?
...
To rename a table in SQL Server, use the sp_rename command:
exec sp_rename 'schema.old_table_name', 'new_table_name'
share
|
improve ...