Re: can this be done in one SQL selcet statement?!

From: Greg Mitchell <gmitchell(at)atdesk(dot)com>
To: "sasan3(at)gmail(dot)com" <sasan3(at)gmail(dot)com>, pgsql-general(at)postgresql(dot)org
Subject: Re: can this be done in one SQL selcet statement?!
Date: 2006-12-08 14:00:07
Message-ID: 45796FE7.9030804@atdesk.com
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First, I think the table design is probably not the best way to do this.
In the relational database world, Table 2 probably should look like this:

NODE1 NODE2
NODE1 NODE3
NODE2 NODE4
NODE2 NODE3

Then you could do:

INSERT INTO table1 SELECT DISTINCT column2 FROM table2 WHERE column2 NOT
IN (SELECT column1 FROM table1);

Greg

sasan3(at)gmail(dot)com wrote:
>
> I have two table:
> -Table1: one column of type TEXT containing label for nodes in a graph
>
> -Table 2: two columns of type TEXT. first column contains node labels
> in a graph. second a list of node labels that the node label in column
> one is connected to.
>
> Example:
> Table1:
> "NODE1"
> "NODE2"
>
> Table 2:
> "NODE1" "NODE2 NODE3"
> "NODE2" "NODE4 NODE3"
>
> Goal:
> split column2 in table2 to individual node names, find a unique
> list of all node names obtained after splitting column2 of table2 and
> insert the ones not already in table1 in table1.
>
>
> Thanks in advance.
>
> S
>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 9: In versions below 8.0, the planner will ignore your desire to
> choose an index scan if your joining column's datatypes do not
> match

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