Suppose the table is this (the first line is just header) h1,h2,v a,,Y a,C,3
Since v of h1=a and h2="" is Y which is not X, the table should be updated to h1,h2,v a,,X a,A,1 a,B,2 ... Suppose the table is this, as v of h1=a and h2="" is X, the table is not changed. h1,h2,v a,,X a,C,3 Suppose the table is this. h1,h2,v a,C,3 since there is no row with h1=a and h2="", the table is updated to h1,h2,v a,,X a,A,1 a,B,2 ... On 1/30/20, David Raymond <david.raym...@tomtom.com> wrote: > I'm not quite following what you're trying to do here. Could you provide a > few examples of "here's what used to be in there", "here's what I want to > insert", "here's what it should like in the end" > > > > -----Original Message----- > From: sqlite-users <sqlite-users-boun...@mailinglists.sqlite.org> On Behalf > Of Peng Yu > Sent: Thursday, January 30, 2020 11:27 AM > To: SQLite mailing list <sqlite-users@mailinglists.sqlite.org> > Subject: [sqlite] conditional insert operations > > Hi, > > Suppose that I have a table with three columns h1, h2, v. I want to > delete all rows with h1=a, and insert rows like the following (data > shown in TSV format), only if there is not an entry with h1=a and > h2="" (empty), it exists but its v is not equal to a value X. > > a,A,v1 > a,B,v2 > ... > > https://www.sqlite.org/lang_insert.html > > I am not sure if there is a way to check an entry to know whether new > entries can be inserted. Could anybody show me an example if this can > be done? > > -- > Regards, > Peng > _______________________________________________ > sqlite-users mailing list > sqlite-users@mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ > sqlite-users mailing list > sqlite-users@mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > -- Regards, Peng _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
