## AwlDBDialect

Description

The AwlDBDialect class handles support for different SQL dialects

This subpackage provides dialect specific support for PostgreSQL, and may, over time, be extended to provide support for other SQL dialects.

If you are looking for the place to add support for other SQL dialects, this is the class that you should be looking at. You might also look at the AwlDatabase class which extends this one, but these are the core capabilities which most probably need attention.

Located in /inc/AwlDBDialect.php (line 33)

Direct descendents

Class | Description
--- | ---
AwlDatabase | Typically there will only be a single instance of the database level class in an application.

Variable Summary
mixed $db
mixed $dialect
Method Summary
AwlDBDialect __construct (string $connection_string, [string $dbuser = null], [string $dbpass = null], [array $options = null])
void GetFields (string $tablename_string)
void GetVersion (handle $pdo)
void Quote (mixed $value, [string $value_type = null])
The ReplaceNamedParameters (string 0, mixed 1)
The ReplaceParameters (string 0, mixed 1)
void SetSearchPath ([ $search_path = null])
void TranslateSQL ( $sql_string)
Variables
mixed $db (line 46)

Holds the PDO database connection

- access: protected

mixed $dialect (line 41)

Holds the name of the database dialect

- access: protected

Methods
Constructor __construct (line 68)

Parses the connection string to ascertain the database dialect. Returns true if the dialect is supported and fails if the dialect is not supported. All code to support any given database should be within in an external include.

The database will be opened.

AwlDBDialect __construct (string $connection_string, [string $dbuser = null], [string $dbpass = null], [array $options = null])

- string $connection_string: The PDO connection string, in all it's glory
- string $dbuser: The database username to connect as
- string $dbpass: The database password to connect with
- array $options: An array of driver options

GetFields (line 134)

Returns the SQL for the current database dialect which will return a two-column resultset containing a list of fields and their associated data types.

void GetFields (string $tablename_string)

- string $tablename_string: The name of the table we want fields from

GetVersion (line 105)

Sets the current search path for the database.

void GetVersion (handle $pdo)

- handle $pdo: A handle to an opened database

Quote (line 178)

Returns $value escaped in an appropriate way for this database dialect.

void Quote (mixed $value, [string $value_type = null])

- mixed $value: The value to be escaped
- string $value_type: The type of escaping desired. If blank this will be worked out from the type of the $value. The special type of 'identifier' can also be used for escaping of SQL identifiers.

ReplaceNamedParameters (line 322)

Replaces named query parameters of the form :name with appropriately escaped substitutions.

The function takes a variable number of arguments, the first is the SQL string, with replaceable ':name' characters (a la DBI). The subsequent parameters being the values to replace into the SQL string.

The values passed to the routine are analyzed for type, and quoted if they appear to need quoting. This can go wrong for (e.g.) NULL or other special SQL values which are not straightforwardly identifiable as needing quoting (or not).

- return: built query string

The ReplaceNamedParameters (string 0, mixed 1)

- string 0: The query string with replacable ':name' identifiers
- mixed 1: A ':name' => 'value' hash of values to replace into the SQL string.

ReplaceParameters (line 266)

Replaces query parameters with appropriately escaped substitutions.

The function takes a variable number of arguments, the first is the SQL string, with replaceable '?' characters (a la DBI). The subsequent parameters being the values to replace into the SQL string.

The values passed to the routine are analyzed for type, and quoted if they appear to need quoting. This can go wrong for (e.g.) NULL or other special SQL values which are not straightforwardly identifiable as needing quoting (or not). In such cases the parameter can be forced to be inserted unquoted by passing it as "array( 'plain' => $param )".

- return: built query string

The ReplaceParameters (string 0, mixed 1)

- string 0: The query string with replacable '?' characters.
- mixed 1: The values to replace into the SQL string.

SetSearchPath (line 87)

Sets the current search path for the database.

void SetSearchPath ([ $search_path = null])

- $search_path

TranslateSQL (line 164)

Translates the given SQL string into a form that will hopefully work for this database dialect. This hook is intended to be used by developers to provide support for differences in database operation by translating the query string in an arbitrary way, such as through a file or database lookup.

The actual translation to other SQL dialects will be application-specific, so that any routines called by this will be external to this library, or will use resources loaded from some source external to this library.

The application developer is expected to use this functionality to solve harder translation problems, but is less likely to call this directly, hopefully switching ->Prepare to ->PrepareTranslated in those cases, and then adding that statement to whatever SQL translation infrastructure is in place.

void TranslateSQL ( $sql_string)

- $sql_string

Documentation generated on Sat, 17 Apr 2010 12:32:23 +1200 by phpDocumentor 1.3.2