大约有 40,000 项符合查询结果(耗时:0.0262秒) [XML]

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What is the best place for storing uploaded images, SQL database or disk file system? [closed]

... I have recently created a PHP/MySQL app which stores PDFs/Word files in a MySQL table (as big as 40MB per file so far). Pros: Uploaded files are replicated to backup server along with everything else, no separate backup strategy is needed (peace of min...
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How to UPSERT (MERGE, INSERT … ON DUPLICATE UPDATE) in PostgreSQL?

...and re-try where necessary. Some attempted solutions also fail to consider SELECT races. If you try the obvious and simple: -- THIS IS WRONG. DO NOT COPY IT. It's an EXAMPLE. BEGIN; UPDATE testtable SET somedata = 'blah' WHERE id = 2; -- Remember, this is WRONG. Do NOT COPY IT. INSERT INTO testt...
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I want to copy table contained from one database and insert onto another database table

...as below. CREATE TABLE db2.table LIKE db1.table; INSERT INTO db2.table SELECT * FROM db1.table; share | improve this answer | follow | ...
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Oracle取前N条记录方法 Oracle实现SELECT TOP N的方法 - 数据库(内核) - 清...

Oracle取前N条记录方法 Oracle实现SELECT TOP N的方法select * from ( select * from tablexxx order by xxx desc ) where rownum <= Noracle数据库不支持mysql中limit, top功...select * from ( select * from tablexxx order by xxx desc ) where rownum <= N oracle数据库不支持mysql中li...
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How to get current date & time in MySQL?

...rent date in epoch format, then you can use UNIX_TIMESTAMP(). For example: select now(3), sysdate(3), unix_timestamp(); would yield +-------------------------+-------------------------+------------------+ | now(3) | sysdate(3) | unix_timestamp() | +--------------------...
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中文网(自研/维护)拓展 · App Inventor 2 中文网

...果是则返回’真’,否则返回’假’。 ResetFirstRun() 重置App的运行状态为第一次运行。 SystemSettings() 跳转到系统设置界面 WirelessSettings() 跳转到无线和网络设置界面 AirPlaneState Component for AirPlaneState ...
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Why is a “GRANT USAGE” created the first time I grant a user privileges?

...henticate. An user with USAGE privilege can run certain SQL commands like 'select 1+1' and 'show processlist'. – Mircea Vutcovici Feb 26 '15 at 16:10 add a comment ...
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Mac SQLite editor [closed]

... info.plist and setting it to YES Running the app on a device Open iTunes Select the device Select the "Apps" tab Scroll down to the "File Sharing" section and select the app The .sqlite file should appear in the right hand pane - select it and "Save to..." Once it's saved open it up in your favour...
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What is the difference between HAVING and WHERE in SQL?

What is the difference between HAVING and WHERE in an SQL SELECT statement? 20 Answers ...
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Difference between string and text in rails?

... load varchar in one go, but store text (and blob) outside of the table. A SELECT name, amount FROM products could, be a lot slower when using text for name than when you use varchar. And since Rails, by default loads records with SELECT * FROM... your text-columns will be loaded. This will probably...