Double entry

[birdy]

Howe can i prevent a double entry in a database.
Users can input their data into table.
But how to prevent a double entry.

Users can enter name and date
So users can enter their names only on one date.

Please help.

[Francesco]

Re: Double entry

birdy wrote:[color=blue]
> Howe can i prevent a double entry in a database.
> Users can input their data into table.
> But how to prevent a double entry.
>
> Users can enter name and date
> So users can enter their names only on one date.
>
> Please help.
>
>[/color]
Hi,

you can make define the name and date field as the primary key for the
table. the primary key is unique and if you try to add another record
with the same value, mysql will give you an error.

[Francesco]

Re: Double entry

birdy wrote:[color=blue]
> Howe can i prevent a double entry in a database.
> Users can input their data into table.
> But how to prevent a double entry.
>
> Users can enter name and date
> So users can enter their names only on one date.
>
> Please help.
>
>[/color]
Hi,

you can make define the name and date field as the primary key for the
table. the primary key is unique and if you try to add another record
with the same value, mysql will give you an error.

[Francesco]

Re: Double entry

birdy wrote:[color=blue]
> Howe can i prevent a double entry in a database.
> Users can input their data into table.
> But how to prevent a double entry.
>
> Users can enter name and date
> So users can enter their names only on one date.
>
> Please help.
>
>[/color]
Hi,

you can make define the name and date field as the primary key for the
table. the primary key is unique and if you try to add another record
with the same value, mysql will give you an error.

[birdy]

Re: Double entry

Sorry that won't work.
Because every member should be able to confirm that they are present on a
specific date.
Also other members must be able to use the same date.
So the combination member and date must be unique.

"Francesco" <please_reply_t o_newsgroup@tha nks.net> schreef in bericht
news:4035d5d7$1 _2@news.tiscali net.ch...[color=blue]
> birdy wrote:[color=green]
> > Howe can i prevent a double entry in a database.
> > Users can input their data into table.
> > But how to prevent a double entry.
> >
> > Users can enter name and date
> > So users can enter their names only on one date.
> >
> > Please help.
> >
> >[/color]
> Hi,
>
> you can make define the name and date field as the primary key for the
> table. the primary key is unique and if you try to add another record
> with the same value, mysql will give you an error.
>[/color]

[birdy]

Re: Double entry

Sorry that won't work.
Because every member should be able to confirm that they are present on a
specific date.
Also other members must be able to use the same date.
So the combination member and date must be unique.

"Francesco" <please_reply_t o_newsgroup@tha nks.net> schreef in bericht
news:4035d5d7$1 _2@news.tiscali net.ch...[color=blue]
> birdy wrote:[color=green]
> > Howe can i prevent a double entry in a database.
> > Users can input their data into table.
> > But how to prevent a double entry.
> >
> > Users can enter name and date
> > So users can enter their names only on one date.
> >
> > Please help.
> >
> >[/color]
> Hi,
>
> you can make define the name and date field as the primary key for the
> table. the primary key is unique and if you try to add another record
> with the same value, mysql will give you an error.
>[/color]

[birdy]

Re: Double entry

Sorry that won't work.
Because every member should be able to confirm that they are present on a
specific date.
Also other members must be able to use the same date.
So the combination member and date must be unique.

"Francesco" <please_reply_t o_newsgroup@tha nks.net> schreef in bericht
news:4035d5d7$1 _2@news.tiscali net.ch...[color=blue]
> birdy wrote:[color=green]
> > Howe can i prevent a double entry in a database.
> > Users can input their data into table.
> > But how to prevent a double entry.
> >
> > Users can enter name and date
> > So users can enter their names only on one date.
> >
> > Please help.
> >
> >[/color]
> Hi,
>
> you can make define the name and date field as the primary key for the
> table. the primary key is unique and if you try to add another record
> with the same value, mysql will give you an error.
>[/color]

[David L]

Re: Double entry

Francesco in the previous post mentioned a primary key on the name *AND* the
date, so it should work...


"birdy" <birdy@quicknet .nl> wrote in message
news:eec23$4036 2d52$d54996e6$2 4592@news.multi kabel.nl...[color=blue]
> Sorry that won't work.
> Because every member should be able to confirm that they are present on a
> specific date.
> Also other members must be able to use the same date.
> So the combination member and date must be unique.
>
> "Francesco" <please_reply_t o_newsgroup@tha nks.net> schreef in bericht
> news:4035d5d7$1 _2@news.tiscali net.ch...[color=green]
> > birdy wrote:[color=darkred]
> > > Howe can i prevent a double entry in a database.
> > > Users can input their data into table.
> > > But how to prevent a double entry.
> > >
> > > Users can enter name and date
> > > So users can enter their names only on one date.
> > >
> > > Please help.
> > >
> > >[/color]
> > Hi,
> >
> > you can make define the name and date field as the primary key for the
> > table. the primary key is unique and if you try to add another record
> > with the same value, mysql will give you an error.
> >[/color]
>
>[/color]

[David L]

Re: Double entry

Francesco in the previous post mentioned a primary key on the name *AND* the
date, so it should work...


"birdy" <birdy@quicknet .nl> wrote in message
news:eec23$4036 2d52$d54996e6$2 4592@news.multi kabel.nl...[color=blue]
> Sorry that won't work.
> Because every member should be able to confirm that they are present on a
> specific date.
> Also other members must be able to use the same date.
> So the combination member and date must be unique.
>
> "Francesco" <please_reply_t o_newsgroup@tha nks.net> schreef in bericht
> news:4035d5d7$1 _2@news.tiscali net.ch...[color=green]
> > birdy wrote:[color=darkred]
> > > Howe can i prevent a double entry in a database.
> > > Users can input their data into table.
> > > But how to prevent a double entry.
> > >
> > > Users can enter name and date
> > > So users can enter their names only on one date.
> > >
> > > Please help.
> > >
> > >[/color]
> > Hi,
> >
> > you can make define the name and date field as the primary key for the
> > table. the primary key is unique and if you try to add another record
> > with the same value, mysql will give you an error.
> >[/color]
>
>[/color]

[David L]

Re: Double entry

Francesco in the previous post mentioned a primary key on the name *AND* the
date, so it should work...


"birdy" <birdy@quicknet .nl> wrote in message
news:eec23$4036 2d52$d54996e6$2 4592@news.multi kabel.nl...[color=blue]
> Sorry that won't work.
> Because every member should be able to confirm that they are present on a
> specific date.
> Also other members must be able to use the same date.
> So the combination member and date must be unique.
>
> "Francesco" <please_reply_t o_newsgroup@tha nks.net> schreef in bericht
> news:4035d5d7$1 _2@news.tiscali net.ch...[color=green]
> > birdy wrote:[color=darkred]
> > > Howe can i prevent a double entry in a database.
> > > Users can input their data into table.
> > > But how to prevent a double entry.
> > >
> > > Users can enter name and date
> > > So users can enter their names only on one date.
> > >
> > > Please help.
> > >
> > >[/color]
> > Hi,
> >
> > you can make define the name and date field as the primary key for the
> > table. the primary key is unique and if you try to add another record
> > with the same value, mysql will give you an error.
> >[/color]
>
>[/color]

[David L]

Re: Double entry

because a primary key can be made up of more than one field..

"David L" <dl@nospam.co m> wrote in message
news:v5xZb.6879 8$Wa.33878@news-server.bigpond. net.au...[color=blue]
> Francesco in the previous post mentioned a primary key on the name *AND*[/color]
the[color=blue]
> date, so it should work...
>
>
> "birdy" <birdy@quicknet .nl> wrote in message
> news:eec23$4036 2d52$d54996e6$2 4592@news.multi kabel.nl...[color=green]
> > Sorry that won't work.
> > Because every member should be able to confirm that they are present on[/color][/color]
a[color=blue][color=green]
> > specific date.
> > Also other members must be able to use the same date.
> > So the combination member and date must be unique.
> >
> > "Francesco" <please_reply_t o_newsgroup@tha nks.net> schreef in bericht
> > news:4035d5d7$1 _2@news.tiscali net.ch...[color=darkred]
> > > birdy wrote:
> > > > Howe can i prevent a double entry in a database.
> > > > Users can input their data into table.
> > > > But how to prevent a double entry.
> > > >
> > > > Users can enter name and date
> > > > So users can enter their names only on one date.
> > > >
> > > > Please help.
> > > >
> > > >
> > > Hi,
> > >
> > > you can make define the name and date field as the primary key for the
> > > table. the primary key is unique and if you try to add another record
> > > with the same value, mysql will give you an error.
> > >[/color]
> >
> >[/color]
>
>[/color]

[David L]

Re: Double entry

because a primary key can be made up of more than one field..

"David L" <dl@nospam.co m> wrote in message
news:v5xZb.6879 8$Wa.33878@news-server.bigpond. net.au...[color=blue]
> Francesco in the previous post mentioned a primary key on the name *AND*[/color]
the[color=blue]
> date, so it should work...
>
>
> "birdy" <birdy@quicknet .nl> wrote in message
> news:eec23$4036 2d52$d54996e6$2 4592@news.multi kabel.nl...[color=green]
> > Sorry that won't work.
> > Because every member should be able to confirm that they are present on[/color][/color]
a[color=blue][color=green]
> > specific date.
> > Also other members must be able to use the same date.
> > So the combination member and date must be unique.
> >
> > "Francesco" <please_reply_t o_newsgroup@tha nks.net> schreef in bericht
> > news:4035d5d7$1 _2@news.tiscali net.ch...[color=darkred]
> > > birdy wrote:
> > > > Howe can i prevent a double entry in a database.
> > > > Users can input their data into table.
> > > > But how to prevent a double entry.
> > > >
> > > > Users can enter name and date
> > > > So users can enter their names only on one date.
> > > >
> > > > Please help.
> > > >
> > > >
> > > Hi,
> > >
> > > you can make define the name and date field as the primary key for the
> > > table. the primary key is unique and if you try to add another record
> > > with the same value, mysql will give you an error.
> > >[/color]
> >
> >[/color]
>
>[/color]

[David L]

Re: Double entry

because a primary key can be made up of more than one field..

"David L" <dl@nospam.co m> wrote in message
news:v5xZb.6879 8$Wa.33878@news-server.bigpond. net.au...[color=blue]
> Francesco in the previous post mentioned a primary key on the name *AND*[/color]
the[color=blue]
> date, so it should work...
>
>
> "birdy" <birdy@quicknet .nl> wrote in message
> news:eec23$4036 2d52$d54996e6$2 4592@news.multi kabel.nl...[color=green]
> > Sorry that won't work.
> > Because every member should be able to confirm that they are present on[/color][/color]
a[color=blue][color=green]
> > specific date.
> > Also other members must be able to use the same date.
> > So the combination member and date must be unique.
> >
> > "Francesco" <please_reply_t o_newsgroup@tha nks.net> schreef in bericht
> > news:4035d5d7$1 _2@news.tiscali net.ch...[color=darkred]
> > > birdy wrote:
> > > > Howe can i prevent a double entry in a database.
> > > > Users can input their data into table.
> > > > But how to prevent a double entry.
> > > >
> > > > Users can enter name and date
> > > > So users can enter their names only on one date.
> > > >
> > > > Please help.
> > > >
> > > >
> > > Hi,
> > >
> > > you can make define the name and date field as the primary key for the
> > > table. the primary key is unique and if you try to add another record
> > > with the same value, mysql will give you an error.
> > >[/color]
> >
> >[/color]
>
>[/color]