Class PgQuery
The PgQuery Class.
This class builds and executes PostgreSQL Queries and traverses the
set of results returned from the query.
Example usage
$sql = "SELECT * FROM mytable WHERE mytype = ?";
$qry = new PgQuery( $sql, $myunsanitisedtype );
if ( $qry->Exec("typeselect", __line__, __file__ )
&& $qry->rows() > 0 )
{
while( $row = $qry->Fetch() ) {
do_something_with($row);
}
}
Methods summary
public
The
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public
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SetConnection( resource $new_connection )
Use a different database connection for this query
Use a different database connection for this query
Parameters
- $new_connection
- The database connection to use.
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public
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_log_error( string $locn, string $tag, string $string, integer $line = 0, string $file = "" )
Log error, optionally with file and line location of the caller.
Log error, optionally with file and line location of the caller.
This function should not really be used outside of PgQuery. For a more
useful generic logging interface consider calling dbg_error_log(...);
Parameters
- $locn
- A string identifying the calling location.
- $tag
- A tag string, e.g. identifying the type of event.
- $string
- The information to be logged.
- $line
- The line number where the logged event occurred.
- $file
- The file name where the logged event occurred.
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public
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rows( )
Provide a rows() method for forward compatibility with AwlQuery.
Provide a rows() method for forward compatibility with AwlQuery.
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public
string
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#
quote( mixed $str = null )
Quote the given string so it can be safely used within string delimiters
in a query.
Quote the given string so it can be safely used within string delimiters
in a query.
Parameters
- $str
- Data to be converted to a string suitable for including as a value in SQL.
Returns
string
NULL, TRUE, FALSE, a plain number, or the original string quoted and with ' and \ characters escaped
See
qpg()
which is where this is really done.
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public
array
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#
Plain( string $field )
Convert a string which has already been quoted and escaped for PostgreSQL
into a magic array so that it will be inserted unmodified into the SQL
string. Use with care!
Convert a string which has already been quoted and escaped for PostgreSQL
into a magic array so that it will be inserted unmodified into the SQL
string. Use with care!
Parameters
- $field
- The value which has alread been quoted and escaped.
Returns
array
An array with the value associated with a key of 'plain'
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public
resource
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#
Exec( string $location = '', integer $line = 0, string $file = '' )
Execute the query, logging any debugging.
Execute the query, logging any debugging.
Example
So that you can nicely enable/disable the queries for a particular class, you
could use some of PHPs magic constants in your call.
$qry->Exec(__CLASS__, __LINE__, __FILE__);
Parameters
- $location
The name of the location for enabling debugging or just
to help our children find the source of a problem. - $line
- The line number where Exec was called
- $file
- The file where Exec was called
Returns
resource
The actual result of the query (FWIW)
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public
mixed
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#
Fetch( boolean $as_array = false )
Fetch the next row from the query results
Fetch the next row from the query results
Parameters
- $as_array
- True if thing to be returned is array
Returns
mixed
query row
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public
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#
UnFetch( )
Set row counter back one
In the case that you may like to fetch the same row twice, for example
if your SQL returns some columns that are the same for each row, and you
want to display them cleanly before displaying the other data repeatedly
for each row.
Example
$master_row = $qry->Fetch();
$qry->UnFetch();
do_something_first($master_row);
while( $row = $qry->Fetch() ) {
do_something_repeatedly($row);
}
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public
mixed
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#
FetchBackwards( boolean $as_array = false )
Fetch backwards from the result resource
Fetch backwards from the result resource
Parameters
- $as_array
- True if thing to be returned is array (default: False
Returns
mixed
query row
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public
string
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#
BuildOptionList( string $current = '', string $location = 'options', array $parameters = false )
Build an option list from the query.
Build an option list from the query.
Parameters
- $current
- Default selection of drop down box (optional)
- $location
- for debugging purposes
- $parameters
- an array further parameters, including 'maxwidth' => 20 to set a maximum width
Returns
string
Select box HTML
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Properties summary
public
resource
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$connection
holds the connection to the database
should be internal
holds the connection to the database
should be internal
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public
string
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$querystring
stores a query string
should be read-only
stores a query string
should be read-only
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public
resource
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$result
stores a resource result
should be internal
stores a resource result
should be internal
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public
integer
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$rownum
number of current row
should be internal, or at least read-only
number of current row
should be internal, or at least read-only
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public
string
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$location
Where we called this query from so we can find it in our code!
Debugging may also be selectively enabled for a $location.
Where we called this query from so we can find it in our code!
Debugging may also be selectively enabled for a $location.
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public
mixed
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$object
The row most recently fetched by a call to Fetch() or FetchBackwards
which will either be an array or an object (depending on the Fetch call).
The row most recently fetched by a call to Fetch() or FetchBackwards
which will either be an array or an object (depending on the Fetch call).
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public
integer
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$rows
number of rows from pg_numrows - for fetching result
should be read-only
number of rows from pg_numrows - for fetching result
should be read-only
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public
string
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$errorstring
The PostgreSQL error message, if the query fails.
Should be read-only, although any successful Exec should clear it
The PostgreSQL error message, if the query fails.
Should be read-only, although any successful Exec should clear it
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public
string
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$execution_time
Stores the query execution time - used to deal with long queries.
should be read-only
Stores the query execution time - used to deal with long queries.
should be read-only
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public
float
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$query_time_warning
How long the query should take before a warning is issued.
How long the query should take before a warning is issued.
This is writable, but a method to set it might be a better interface.
The default is 0.3 seconds.
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