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Check if table exists in SQL Server
...always best to use an INFORMATION_SCHEMA view. These views are (mostly) standard across many different databases and rarely change from version to version.
To check if a table exists use:
IF (EXISTS (SELECT *
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_SCHEMA = ...
OnNotify函数 ON_NOTIFY消息总结 - C/C++ - 清泛网 - 专注C/C++及内核技术
...的消息映射，然后调用。(checks the message map for notification handlers to call.)。
一般说来，你不用重载OnNotify。你可以写一个处理函数，然后添加消息映射（这个就不用详解了吧）。
当然，也可以通过重载OnNotify函数处理指定控件的...
Create unique constraint with null columns
...(user_id, menu_id, recipe_id), you cannot base CLUSTER on a partial index, and queries without a matching WHERE condition cannot use the partial index. (It seems unlikely you'd want a FK reference three columns wide - use the PK column instead).
If you need a complete index, you can alternatively d...
How to create standard Borderless buttons (like in the design guideline mentioned)?
I was just checking the design guidelines and wondering about the borderless buttons.
I goggled and tried to find in the source but can't bring it together by myself.
Is this the normal Button widget but you add a custom (Android default) style?
How to make these borderless buttons (of course you ca...
Alternate output format for psql
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I just needed to spend more time staring at the documentation. This command:
\x on
will do exactly what I wanted. Here is some sample output:
select * from dda where u_id=24 and dda_is_deleted='f';
-[ RECORD 1 ]------+--------------------------------------------------------------------------...
How to get last N records with activerecord?
...unnecessary to order the data twice, I'm currently getting the count first and using it with offset
– JtR
Jan 7 '09 at 14:12
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PDO get the last ID inserted
I have a query, and I want to get the last ID inserted. The field ID is the primary key and auto incrementing.
3 Answers
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How to get WordPress post featured image URL
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Check the code below and let me know if it works for you.
<?php if (has_post_thumbnail( $post->ID ) ): ?>
<?php $image = wp_get_attachment_image_src( get_post_thumbnail_id( $post->ID ), 'single-post-thumbnail' ); ?>
<div...
SQLite add Primary Key
... suggested solution is to create a new table with the correct requirements and copy your data into it, then drop the old table.
here is the official documentation about this: http://sqlite.org/faq.html#q11
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Update multiple rows in same query using PostgreSQL
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You can also use update ... from syntax and use a mapping table. If you want to update more than one column, it's much more generalizable:
update test as t set
column_a = c.column_a
from (values
('123', 1),
('345', 2)
) as c(column_b, column_a)
wher...