Try:
INSERT INTO table1 ( column1 )
SELECT col1
FROM table2
This is standard ANSI SQL and should work on any DBMS
It definitely works for:
- Oracle
- MS SQL Server
- MySQL
- Postgres
- SQLite v3
- Teradata
- DB2
- Sybase
- Vertica
- HSQLDB
- H2
- AWS RedShift
- SAP HANA
- Google Spanner
There is actually a (subtle) difference between the two. Imagine you have the following code in File1.cs:
// File1.cs
using System;
namespace Outer.Inner
{
class Foo
{
static void Bar()
{
double d = Math.PI;
}
}
}
Now imagine that someone adds another file (File2.cs) to the project that looks like this:
// File2.cs
namespace Outer
{
class Math
{
}
}
The compiler searches Outer
before looking at those using
directives outside the namespace, so it finds Outer.Math
instead of System.Math
. Unfortunately (or perhaps fortunately?), Outer.Math
has no PI
member, so File1 is now broken.
This changes if you put the using
inside your namespace declaration, as follows:
// File1b.cs
namespace Outer.Inner
{
using System;
class Foo
{
static void Bar()
{
double d = Math.PI;
}
}
}
Now the compiler searches System
before searching Outer
, finds System.Math
, and all is well.
Some would argue that Math
might be a bad name for a user-defined class, since there's already one in System
; the point here is just that there is a difference, and it affects the maintainability of your code.
It's also interesting to note what happens if Foo
is in namespace Outer
, rather than Outer.Inner
. In that case, adding Outer.Math
in File2 breaks File1 regardless of where the using
goes. This implies that the compiler searches the innermost enclosing namespace before it looks at any using
directive.
Best Answer
I'm loading 50,000 records in 15 or so seconds using Array Binding in ODP.NET
It works by repeatedly invoking a stored procedure you specify (and in which you can do updates/inserts/deletes), but it passes the multiple parameter values from .NET to the database in bulk.
Instead of specifying a single value for each parameter to the stored procedure you specify an array of values for each parameter.
Oracle passes the parameter arrays from .NET to the database in one go, and then repeatedly invokes the stored procedure you specify using the parameter values you specified.
http://www.oracle.com/technetwork/issue-archive/2009/09-sep/o59odpnet-085168.html
/Damian