<row>

<entry><literal>verify-ca</></entry>

<entry>only try an <acronym>SSL</> connection, and verify that

the server certificate is issued by a trusted<acronym>CA</>

</entry>

the server certificate is issued by a trustedcertificate

authority (<acronym>CA</>)</entry>

</row>

<row>

<para>

At any time during connection, the status of the connection can be

checked by calling <function>PQstatus</>. If thisgives <symbol>CONNECTION_BAD</>, then the

connection procedure has failed; ifit gives <function>CONNECTION_OK</>, then the

checked by calling <function>PQstatus</>. If thiscall returns <symbol>CONNECTION_BAD</>, then the

connection procedure has failed; ifthe call returns <function>CONNECTION_OK</>, then the

connection is ready. Both of these states are equally detectable

from the return value of <function>PQconnectPoll</>, described above. Other states might also occur

during (and only during) an asynchronous connection procedure. These

<para>

Parses a connection string and returns the resulting options as an

array; or returns <symbol>NULL</> if there is a problem with the connection

string. This can be used todetermine

string. Thisfunctioncan be used toextract

the <function>PQconnectdb</function> options in the provided

connection string. The return value points to an array of

<structname>PQconninfoOption</structname> structures, which ends

<synopsis>

int PQprotocolVersion(const PGconn *conn);

</synopsis>

Applications might wish to use this to determine whether certain

Applications might wish to use thisfunctionto determine whether certain

features are supported. Currently, the possible values are 2 (2.0

protocol), 3 (3.0 protocol), or zero (connection bad). This will

protocol), 3 (3.0 protocol), or zero (connection bad). The

protocol version will

not change after connection startup is complete, but it could

theoretically change during a connection reset. The 3.0 protocol

will normally be used when communicating with

<synopsis>

int PQserverVersion(const PGconn *conn);

</synopsis>

Applications might use this to determine the version of the database

Applications might use thisfunctionto determine the version of the database

server they are connected to. The number is formed by converting

the major, minor, and revision numbers into two-decimal-digit

numbers and appending them together. For example, version 8.1.5

Nearly all <application>libpq</> functions will set a message for

<function>PQerrorMessage</function> if they fail. Note that by

<application>libpq</application> convention, a nonempty

<function>PQerrorMessage</function> result canbe multiple lines,

<function>PQerrorMessage</function> result canconsist of multiple lines,

and will include a trailing newline. The caller should not free

the result directly. It will be freed when the associated

<structname>PGconn</> handle is passed to

</varlistentry>

</variablelist>

It is allowed to include multiple SQL commands (separated by semicolons)

in the command string. Multiple queries sent in a single

The command string can include multiple SQL commands

(separated by semicolons). Multiple queries sent in a single

<function>PQexec</> call are processed in a single transaction, unless

there are explicit <command>BEGIN</command>/<command>COMMIT</command>

commands included in the query string to divide it into multiple

<para>

The return value is 1 if the cancel request was successfully

dispatched and 0 if not. If not, <parameter>errbuf</> is filled

with an error message explaining why not. <parameter>errbuf</>

with anexplanatoryerror message. <parameter>errbuf</>

must be a char array of size <parameter>errbufsize</> (the

recommended size is 256 bytes).

</para>