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Difference between string and text in rails?
...l is converted into its respective column type in query language.
with MySQL :string is mapped to VARCHAR(255)
- http://guides.rubyonrails.org/migrations.html
:string | VARCHAR | :limit => 1 to 255 (default = 255)
:text | TINYTEXT, TEXT, MEDIUMTEXT, or...
What does WISC (stack) mean? [closed]
... for the software/technology bundle/stack representing Linux , Apache , MySQL , PHP . There are a few passing references on the Web that use the acronym WISC to speak of the other (supposedly Microsoft-centric) software/technology bundle/stack in contrast to LAMP. There is, however, no Wikip...
update columns values with column of another table based on condition [duplicate]
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it's not working in mysql
– cikatomo
Sep 30 '15 at 19:30
22
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On duplicate key ignore? [duplicate]
...because it will additionally hold Next-Key lock on your indexes. More: dev.mysql.com/doc/refman/5.7/en/…
– Dzmitry Lazerka
Mar 14 '17 at 7:13
1
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How to remove not null constraint in sql server using query
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Why does this work and not the above accepted answer for mysql ?
– HopeKing
Feb 13 '18 at 8:47
1
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Altering a column to be nullable
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If this was MySQL syntax, the type would have been missing, as some other responses point out.
Correct MySQL syntax would have been:
ALTER TABLE Merchant_Pending_Functions MODIFY NumberOfLocations INT NULL
Posting here for clarity to ...
Delete terminal history in Linux [closed]
...can use previous commands again. Great feature. However, I started logging mysql into mysql with the sensitive details in the command.
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Can I change a column from NOT NULL to NULL without dropping it?
... I tried with alter column and it didn't work with the latest mysql server. I tried with modify column and it worked. Strange...
– Kostas Andrianos
Aug 19 '17 at 15:29
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常用Sql - 爬虫/数据库 - 清泛IT社区，为创新赋能！
本帖最后由 zqp2013 于 2015-3-17 22:06 编辑
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` &nbs...
PHP编译configure时常见错误 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...e gmp.h
centos: yum install gmp-devel
14、Configure: error: Cannot find MySQL header files under /usr. Note that the MySQL client library is not bundled anymore!
yum install mysql-devel (For Redhat & Fedora)
# apt-get install libmysql++-dev (For Ubuntu)
15、Configure: error: Please reinstall ...