module DbiPool: module MyPool = DbiPool (Dbi_postgres)
creates a pool of PostgreSQL database handles. To use them:
let dbh = MyPool.get r "database_name"
Gets you a new or recycled database handle dbh which is valid until
the end of the current Apache request.
| Parameters: |
|
type
val get : Netcgi.cgi ->
?host:string ->
?port:string ->
?user:string -> ?password:string -> string -> connectionExample: module MyPool = DbiPool(Dbi_postgres)
let dbh = MyPool.get request "database_name"
Returns an unused Dbi.connection handle from the pool of
database handles. Or it may create a new database connection
and return that.
The parameters uniquely identify the database name (eg. "comments") and optional parameters. Separate pools are maintained for each combination of parameters.
The connection is automatically returned to the pool at the
end of the cgi request. After this time the connection may
be given away to another user. For this reason, the calling
code must NEVER stash the connection across requests
(instead, call get to get a new handle each time).
On returning the handle to the pool, the pool performs a
ROLLBACK operation on the handle, thus losing any changes
(INSERT, etc.) made to the database. If the program wants to
preserve changes, it must perform a COMMIT operation itself,
by calling Dbi.connection.commit.
