Sql – Why is .NET Sql Server access faster than Excel Interop

comexcel-interopnetsql server

This might be a loaded question, and it might get voted down, but it completely frustrates me.

When you use SQL Server in your development the data access is fast and efficient, but when you use COM to talk to Excel it is piggy slow.

It doesn't matter what data access technology you use, ADO, ADO.NET, LINQ, Entity Framework, Astoria (ADO.NET Data Services), they are all quicker than automating Excel.

If all you want is the data in cell "A1" from a Workbook, you need an Excel.Application, Excel.Workbook, Excel.Worksheet, and Excel.Range objects, just to get one data point.

WTF, Why is talking to SQL Server more efficient than talking to Excel? Excel is local and Sql Server may not be.

TIA
Chris

Best Answer

Because spinning up a big monolithic executable that was designed as an interactive application is slower than talking over a fast network to an application that was designed for the purpose.

Syntax:

ALTER TABLE {TABLENAME} 
ADD {COLUMNNAME} {TYPE} {NULL|NOT NULL} 
CONSTRAINT {CONSTRAINT_NAME} DEFAULT {DEFAULT_VALUE}
WITH VALUES

Example:

ALTER TABLE SomeTable
        ADD SomeCol Bit NULL --Or NOT NULL.
 CONSTRAINT D_SomeTable_SomeCol --When Omitted a Default-Constraint Name is autogenerated.
    DEFAULT (0)--Optional Default-Constraint.
WITH VALUES --Add if Column is Nullable and you want the Default Value for Existing Records.

Notes:

Optional Constraint Name:
If you leave out CONSTRAINT D_SomeTable_SomeCol then SQL Server will autogenerate
a Default-Contraint with a funny Name like: DF__SomeTa__SomeC__4FB7FEF6

Optional With-Values Statement:
The WITH VALUES is only needed when your Column is Nullable
and you want the Default Value used for Existing Records.
If your Column is NOT NULL, then it will automatically use the Default Value
for all Existing Records, whether you specify WITH VALUES or not.

How Inserts work with a Default-Constraint:
If you insert a Record into SomeTable and do not Specify SomeCol's value, then it will Default to 0.
If you insert a Record and Specify SomeCol's value as NULL (and your column allows nulls),
then the Default-Constraint will not be used and NULL will be inserted as the Value.

Notes were based on everyone's great feedback below.
Special Thanks to:
@Yatrix, @WalterStabosz, @YahooSerious, and @StackMan for their Comments.

Sql – How to return only the Date from a SQL Server DateTime datatype

SELECT DATEADD(dd, 0, DATEDIFF(dd, 0, @your_date))

for example

SELECT DATEADD(dd, 0, DATEDIFF(dd, 0, GETDATE()))

gives me

2008-09-22 00:00:00.000

Pros:

No varchar<->datetime conversions required
No need to think about locale

Best Answer

Related Solutions

Sql – Add a column with a default value to an existing table in SQL Server

Syntax:

Example:

Notes:

Sql – How to return only the Date from a SQL Server DateTime datatype

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