What would this look like in SQL (SQL Server if you want to be particular)?
这在SQL中会是什么样子(SQL Server,如果你想特别的话)?
// where people is a list of Person objects with property Name
bool bobs = people.All(p => p.Name == "Bob");
2 个解决方案
#1
5
You would check if there are any records that doesn't match the criteria:
您将检查是否有任何记录与条件不符:
not exists(select * from Persons where not Name = 'Bob')
As the rules for comparing to null are different between C# and SQL, you would need a condition for null values if the field allows them:
由于C#和SQL之间的比较规则不同,如果字段允许,则需要一个空值条件:
not exists(select * from Persons where Name <> 'Bob' or Name is null)
#2
3
I'm not sure what query exactly Linq will create but the equivalent in SQL is the ALL operator:
我不确定究竟Linq将创建什么查询,但SQL中的等价物是ALL运算符:
'Bob' = ALL (SELECT name FROM people)
#1
5
You would check if there are any records that doesn't match the criteria:
您将检查是否有任何记录与条件不符:
not exists(select * from Persons where not Name = 'Bob')
As the rules for comparing to null are different between C# and SQL, you would need a condition for null values if the field allows them:
由于C#和SQL之间的比较规则不同,如果字段允许,则需要一个空值条件:
not exists(select * from Persons where Name <> 'Bob' or Name is null)
#2
3
I'm not sure what query exactly Linq will create but the equivalent in SQL is the ALL operator:
我不确定究竟Linq将创建什么查询,但SQL中的等价物是ALL运算符:
'Bob' = ALL (SELECT name FROM people)