大约有 9,000 项符合查询结果（耗时：0.0292秒） [XML]
How to ALTER multiple columns at once in SQL Server
...simple metadata change. You are welcome to join my lecture tomorrow about "SQL Internals - Physical Table Structure under the hood, and implementation on real case scenarios" to see it all in practical :-)
– Ronen Ariely
Mar 12 '19 at 17:19
...
django syncdb and an updated model
...m using South for migrating models with a custom db backend (like django-mssql)
– Don
Apr 4 '11 at 7:32
1
...
Oracle: how to UPSERT (update or insert into a table?)
...before the insert regardless of how many concurrent calls are made to same SQL code. Worst case, you may get lots of contention and Oracle will take much longer to reach a final state.
– Neo
Nov 6 '12 at 13:23
...
How to split a string literal across multiple lines in C / Objective-C?
I have a pretty long sqlite query:
9 Answers
9
...
MongoDB数据导出导入工具：mongoexport,mongoimport - 大数据 & AI - 清泛...
...ts.dat
connected to: 127.0.0.1
exported 9 records
命令执行完后使用ll命令查看，发现目录下生成了一个students.dat的文件
-rw-r--r-- 1 root root 869 Aug 21 00:05 students.dat
查看该文件信息，具体信息如下：
[root@localhost mongodb]# cat students.dat
...
Is there any boolean type in Oracle databases?
... any Boolean type in Oracle databases, similar to the BIT datatype in Ms SQL Server?
11 Answers
...
What is causing this ActiveRecord::ReadOnlyRecord error?
... you use this option, saving the same
record will now fail. Use find_by_sql
to work around.
Using find_by_sql is not really an alternative as it returns raw row/column data, not ActiveRecords. You have two options:
Force the instance variable @readonly to false in the record (hack)
Use :in...
Postgis installation: type “geometry” does not exist
...eate table with Postgis. I do it by this page . But when I import postgis.sql file, I get a lot of errors:
10 Answers
...
Foreign key constraint may cause cycles or multiple cascade paths?
...
SQL Server does simple counting of cascade paths and, rather than trying to work out whether any cycles actually exist, it assumes the worst and refuses to create the referential actions (CASCADE): you can and should still cr...
Postgres: INSERT if does not exist already
...
@TusharJain prior to PostgreSQL 9.5 you can do an "old fashioned" UPSERT (with CTE) but you may experience problems with race conditions and it will not be performant as 9.5 style. There is a good detail about upsert on this blog (in the updated area at...