On Wed, 25 Mar 2009 13:06:24 -0400, "Wilson, Ron P" <ronald.wil...@tycoelectronics.com> wrote:
>Cool! I didn't think of doing that. >I presume this would incur a performance hit >on insert/update to check the constraint Not much. The column data is _dynamically_ typed, so SQLite will determine the type of each value offered anyway. >and sqlite3_prepare* would return SQLITE_CONSTRAINT >if the check failed. Right? Wrong. sqlite3_prepare* doesn't know the data you are going to offer with sqlite3_bind*. The same 'prepared' statement can be used with valid and invalid data. CONSTRAINT violations will be discovered during VM execution of your INSERT / UPDATE statements. See how it works with something like: EXPLAIN INSERT ....... ; >RW > >Ron Wilson, S/W Systems Engineer III, Tyco Electronics, 434.455.6453 > > > > > >If you want to place a restriction on a column such that it will only > >hold an integer (for example) you can use a CHECK constraint. > > > > CREATE TABLE example1(x INTEGER CHECK( typeof(x)='integer' )); > > > >D. Richard Hipp > >d...@hwaci.com > > > > > > > >_______________________________________________ > >sqlite-users mailing list > >sqlite-users@sqlite.org > >http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >_______________________________________________ >sqlite-users mailing list >sqlite-users@sqlite.org >http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users -- ( Kees Nuyt ) c[_] _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
