Combining two Tables into one TempTable, with a condition.

Hi,

I'm very new to Sql, and need to combine information from two tables into one temp table. All tables have the same structure.

The problem is I want to set a condition that if Field 1 is already in the TempTable, dont include that field from the second table. Along the lines of

Table1 Description = Blue, if Table 2 Description = Blue, dont include this row.

I have been trying to use INSERT..SELECT and UNION. , the only problem I have is that I cannot come up with a working conditional statement to prevent both complete sets of data being written to the TempTable.

I'm using Sql Server 2005 deveoper Edition and VS2005Pro.

Any ideas on how to get around this would be appreciated.

Tailor

Hi Tailor,

I'm not 100% clear on what your problem is. Is it that you wanted to union two tables and insert this result into a temp table only if data for a particular column (pk I presume) doesn't already exist in the temp table, or is it that you want to union the result of two tables but only select (and thus insert) distinct rows?

Can you provide a bit more info?

Cheers

Rob

|||

Hi Rob,

Thanks for your reply, I'll try to make this a little clearer with some code.

INSERT INTO tempTable (Description,Id,Reference)

SELECT Description,Id,Reference

From Table1

Where (Id = 'STR001')

UNION

SELECT Description,Id,Reference

FROM Table2

WHERE (Id = 'STR001') AND Description != Table1.Description.

Without the AND statement, all data from both tables is inserted in tempTable, however with the And statement, I get the error message.

'The multi-part identifier Table1.Description could not be bound'

If the description from Table2, matches the Description in Table1, I dont want to include the row in the TempTable.

Sorry if i'm not too clear. At 64, trying to learn VS2005, Sql2005, and intergrating excel in my code, and write a reasonable sized application, all in six months is not something I can recommend. There is just so much to learn, and I dont have a good grasp of a lot of the basics.

If you can suggest a workable solution to my problem, it would be much appreciated.

John

|||

INSERT INTO tempTable (Description,Id,Reference)

SELECT Description,Id,Reference

From Table1

Where (Id = 'STR001')

INSERT INTO tempTable (Description,Id,Reference)

SELECT Description,Id,Reference

FROM Table2 t left outer join temptable tt on t.description = tt.description

WHERE (t.Id = 'STR001') AND tt.description is null

Regards

|||

This is a bit of a messy solution

either

1. Insert the data from both tables with a UNION, but place the UNION statement into a subquery and alias the columns to be inserted.

2. Insert data from table1. Then do the same insert from table2 where NOT EXISTS in the temp table (or table1, either will work). This is a common task you will need to learn to do in SQL Server

|||

Hi JMattias and SHughes,

Thank you both, very much, for your replies. It not only solved the problem, I learnt a lot more on the way through.

Your assistance is greatly appreciated.

John

sqlsql