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><A
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>1.4. Database Connection Functions</A
></H1
>
<P
> <P
></P
></P><UL
><LI
> <P
> <TT
CLASS="FUNCTION"
>PgConnection</TT
>
makes a new connection to a backend database server.
</P><PRE
CLASS="SYNOPSIS"
>PgConnection::PgConnection(const char *conninfo)</PRE
><P>
The <TT
CLASS="PARAMETER"
><I
>conninfo</I
></TT
> string is the same as for the underlying
<SPAN
CLASS="APPLICATION"
>libpq</SPAN
> <TT
CLASS="FUNCTION"
>PQconnectdb</TT
> function.
</P
>
<P
> Although typically called from one of the access classes, a connection to
a backend server is possible by creating a <TT
CLASS="CLASSNAME"
>PgConnection</TT
> object.
</P
>
</LI
><LI
> <P
> <TT
CLASS="FUNCTION"
>ConnectionBad</TT
>
returns whether or not the connection to the backend server succeeded or
failed.
</P><PRE
CLASS="SYNOPSIS"
>bool PgConnection::ConnectionBad() const</PRE
><P>
Returns true if the connection failed.
</P
>
</LI
><LI
> <P
> <TT
CLASS="FUNCTION"
>Status</TT
>
returns the status of the connection to the backend server.
</P><PRE
CLASS="SYNOPSIS"
>ConnStatusType PgConnection::Status()</PRE
><P>
Returns either <TT
CLASS="SYMBOL"
>CONNECTION_OK</TT
> or
<TT
CLASS="SYMBOL"
>CONNECTION_BAD</TT
> depending on the state of the
connection.
</P
>
</LI
><LI
> <P
> <TT
CLASS="FUNCTION"
>PgDatabase</TT
>
makes a new connection to a backend database server.
</P><PRE
CLASS="SYNOPSIS"
>PgDatabase(const char *conninfo)</PRE
><P>
After a <TT
CLASS="CLASSNAME"
>PgDatabase</TT
> has been created it should be checked to make sure
the connection to the database succeeded before sending
queries to the object. This can easily be done by
retrieving the current status of the <TT
CLASS="CLASSNAME"
>PgDatabase</TT
> object with the
<TT
CLASS="FUNCTION"
>Status</TT
> or <TT
CLASS="FUNCTION"
>ConnectionBad</TT
> methods.
</P
>
</LI
><LI
> <P
> <TT
CLASS="FUNCTION"
>DBName</TT
>
returns the name of the current database.
</P><PRE
CLASS="SYNOPSIS"
>const char *PgConnection::DBName()</PRE
><P>
</P
>
</LI
><LI
> <P
> <TT
CLASS="FUNCTION"
>Notifies</TT
>
returns the next notification from a list of unhandled notification messages
received from the backend.
</P><PRE
CLASS="SYNOPSIS"
>PGnotify* PgConnection::Notifies()</PRE
><P>
See <TT
CLASS="FUNCTION"
>PQnotifies</TT
> in <SPAN
CLASS="APPLICATION"
>libpq</SPAN
> for details.
</P
>
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