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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
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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 ...
Cannot issue data manipulation statements with executeQuery()
In MySQL I have two tables, tableA and tableB . I am trying to execute two queries:
10 Answers
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JOIN queries vs multiple queries
... you are joining 3 or more tables on different keys, often databases (i.e. mysql) can only use one index per table, meaning maybe one of the joins will be fast (and use an index) whereas the others will be extremely slow. For multiple queries, you can optimize the indexes to use for each query.
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Should I commit or rollback a read transaction?
...timization points for your app. If you're really curious, you can find the mySQL transaction handling code at bazaar.launchpad.net/~mysql/mysql-server/mysql-6.0/annotate/…
– Mark Brackett
May 21 '10 at 15:05
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Error Code: 1005. Can't create table '…' (errno: 150)
...exceeds the maximum length of 64 characters.
For more details, refer to: MySQL Error Number 1005 Can’t create table
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