Class Sql.mysql

Inheritance graph

Description

This class encapsulates a connection to a MySQL server, and implements the glue needed to access the Mysql module from the generic SQL module.

Typed mode

When query results are returned in typed mode, the MySQL data types are represented like this:

The NULL value

Returned as Val.null.

BIT, TINYINT, BOOL, SMALLINT, MEDIUMINT, INT, BIGINT

Returned as pike integers.

FLOAT, DOUBLE

Returned as pike floats.

DECIMAL

Returned as pike integers for fields that are declared to contain zero decimals, otherwise returned as Gmp.mpq objects.

DATE, DATETIME, TIME, YEAR

Returned as strings in their display representation (see the MySQL manual).

Calendar objects are not used partly because they always represent a specific point or range in time, which these MySQL types do not.

TIMESTAMP

Also returned as strings in the display representation.

The reason is that it's both more efficient and more robust (wrt time zone interpretations) to convert these to unix timestamps on the MySQL side rather than in the client glue. I.e. use the UNIX_TIMESTAMP function in the queries to retrieve them as unix timestamps on integer form.

String types

All string types are returned as pike strings. The MySQL glue can handle charset conversions for text strings - see set_charset and set_unicode_decode_mode.

Inherit mysql: inherit Mysql.mysql : mysql