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What is the difference between Non-Repeatable Read and Phantom Read?
What is the difference between non-repeatable read and phantom read?
9 Answers
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Should try…catch go inside or outside a loop?
...ch structures are placed. Internally, they are implemented as a code-range table in a structure that is created when the method is called. While the method is executing, the try/catch structures are completely out of the picture unless a throw occurs, then the location of the error is compared again...
Checking if a SQL Server login already exists
...ction. Attacker can pass a @loginName like x] with password ''y'';\r\ndrop table foo;\r\n
– Remus Rusanu
Sep 4 '09 at 14:47
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Are foreign keys really necessary in a database design?
... code using things like ON DELETE CASCADE. This means that if you have one table containing users and another containing orders or something, then deleting a user could automatically delete all orders that point to that user.
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How does the const constructor actually work?
... time. They are canonicalized at compile time and stored in special lookup tables (where they are hashed by their canonical signatures) from which they are later reused.
P.S.
The form #Foo#int#1#int#1 used in these samples is only used for comparison purposes and it is not a real form of canonical...
Dynamic SELECT TOP @var In SQL Server
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SELECT TOP (@count) * FROM SomeTable
This will only work with SQL 2005+
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Using an ORM or plain SQL? [closed]
...ased on Java beans get/set methods. This is a TON of boilerplate for every table, for every column and ... here's the real anti-pattern: Just to expose every field as if it were public. In effect, having a get/set method on fields in an object/table/row is very close to violating every tenant of inf...
Difference between @OneToMany and @ElementCollection?
...ring> strings;
Simpler, isn't it? Note that you can still control the table and column names using @CollectionTable annotation.
See also:
Java Persistence/ElementCollection
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Group by month and year in MySQL
Given a table with a timestamp on each row, how would you format the query to fit into this specific json object format.
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Subset of rows containing NA (missing) values in a chosen column of a data frame
...t "NA" strings to NA values, and let "NULL" strings as is).
If using read.table() or read.csv(), you should consider the "na.strings" argument to do clean data import, and always work with real R NA values.
An example, working in both cases "NULL" and "NA" cells :
DF <- read.csv("file.csv", na...