Database

TheJudeDude wrote:

I have tried SELECT * From Table Where x = NULL...that doesn't work.

SELECT * FROM Table WHERE x IS NULL

Jethro63 wrote:

But what if the table does not yet exist? What if the purpose of the procedure in question is to check for existence of a certain table and create it if its not there?

IF EXISTS (SELECT * FROM INFORMATION_SCHEME.TABLES WHERE TABLE_NAME = 'MyTableName')
BEGIN
    -- Do stuff based on the existance of the table
END
ELSE
BEGIN
    -- Do stuff based on the nonexistance of the table
END

Jethro63 wrote:

First of all, it is not clear to me if I can indeed execute a "CREATE TABLE" SQL statement using SqlCommand. Can I?

Jethro63 wrote:

Which method should I use? "ExecuteNonQuery", "ExecuteScalar"?

Jethro63 wrote:

So, at this point, I don't know if it is simply, my SQL syntax, or I am miss-using SqlCommand object, or if I simply cannot do this with an SqlCommand object.

Jethro63 wrote:

how can I detect if the database already contains the table?

IF NOT EXISTS (SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME='MyTableName')
BEGIN
    -- Put table creation code here
END

SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = 'MyTableName'

<br />
SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = StationData<br />

<br />
SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = [StationData]<br />

gabriel123456 wrote:

I want to select the distinct values from C1

gabriel123456 wrote:

where there is value 'a' in C2 and in C3 the value is NULL

gabriel123456 wrote:

or C2 does not contain value 'a' for the value in C1

SELECT DISTINCT C1 WHERE (C2 = 'a' AND C3 IS NULL) OR (C2 <> 'a')