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Does Foreign Key improve query performance?
...Keys are a referential integrity tool, not a performance tool. At least in SQL Server, the creation of an FK does not create an associated index, and you should create indexes on all FK fields to improve look up times.
shar...
LINQ to SQL - Left Outer Join with multiple join conditions
I have the following SQL, which I am trying to translate to LINQ:
6 Answers
6
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Generating a UUID in Postgres for Insert statement?
...default. You must load it into your database to use it.
For modern PostgreSQL versions (9.1 and newer) that's easy:
CREATE EXTENSION IF NOT EXISTS "uuid-ossp";
but for 9.0 and below you must instead run the SQL script to load the extension. See the documentation for contrib modules in 8.4.
For...
Better techniques for trimming leading zeros in SQL Server?
...rflow.com/questions/662383/better-techniques-for-trimming-leading-zeros-in-sql-server
DECLARE @retVal VarChar(128),
@pattern varChar(10)
SELECT @pattern = '%[^'+@stripChar+']%'
SELECT @retVal = CASE WHEN SUBSTRING(@string, PATINDEX(@pattern, @string+'.'), LEN(@string)) = '' T...
How to force LINQ Sum() to return 0 while source collection is empty
... handled method by the EF Queryable Provider and will generate the related SQL statement.
– Simon Belanger
Aug 11 '15 at 1:52
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MySQL query to get column names?
I'd like to get all of a mysql table's col names into an array in php?
21 Answers
21
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Case in Select Statement
I have an SQL statement that has a CASE from SELECT and I just can't get it right. Can you guys show me an example of CASE where the cases are the conditions and the results are from the cases. For example:
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MFC的多国语言界面的实现 - C/C++ - 清泛网 - 专注C/C++及内核技术
...MFC的资源文件就提供了对多国不同语言的支持功能，如果使用MFC开发，直接用资源文件自带的多国语言支持，可以省去不少的麻烦。
下面就介绍给MFC程序添加中英文的支持，开发环境为VS2010。
1． 新建工程
新建了一个对话框...
sql ORDER BY multiple values in specific order?
Ok I have a table with a indexed key and a non indexed field.
I need to find all records with a certain value and return the row.
I would like to know if I can order by multiple values.
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Java: Get month Integer from Date
... if you use date.toInstant() and you happen to be working with a java.sql.Date (the child of java.util.Date) then you will get an UnsupportedOperationException. Try new java.sql.Date(src.getTime()).toLocalDate()
– Adam
Feb 24 '17 at 14:15
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