session.go

// Copyright (c) 2012-present The upper.io/db authors. All rights reserved.
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
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// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

package db

import (
	"context"
	"database/sql"
)

// Session is an interface that defines methods for database adapters.
type Session interface {
	// ConnectionURL returns the DSN that was used to set up the adapter.
	ConnectionURL() ConnectionURL

	// Name returns the name of the database.
	Name() string

	// Ping returns an error if the DBMS could not be reached.
	Ping() error

	// Collection receives a table name and returns a collection reference. The
	// information retrieved from a collection is cached.
	Collection(name string) Collection

	// Collections returns a collection reference of all non system tables on the
	// database.
	Collections() ([]Collection, error)

	// Save creates or updates a record.
	Save(record Record) error

	// Get retrieves a record that matches the given condition.
	Get(record Record, cond interface{}) error

	// Delete deletes a record.
	Delete(record Record) error

	// Reset resets all the caching mechanisms the adapter is using.
	Reset()

	// Close terminates the currently active connection to the DBMS and clears
	// all caches.
	Close() error

	// Driver returns the underlying driver of the adapter as an interface.
	//
	// In order to actually use the driver, the `interface{}` value needs to be
	// casted into the appropriate type.
	//
	// Example:
	//  internalSQLDriver := sess.Driver().(*sql.DB)
	Driver() interface{}

	// SQL returns a special interface for SQL databases.
	SQL() SQL

	// Tx creates a transaction block on the default database context and passes
	// it to the function fn. If fn returns no error the transaction is commited,
	// else the transaction is rolled back. After being commited or rolled back
	// the transaction is closed automatically.
	Tx(fn func(sess Session) error) error

	// TxContext creates a transaction block on the given context and passes it to
	// the function fn. If fn returns no error the transaction is commited, else
	// the transaction is rolled back. After being commited or rolled back the
	// transaction is closed automatically.
	TxContext(ctx context.Context, fn func(sess Session) error, opts *sql.TxOptions) error

	// Context returns the context used as default for queries on this session
	// and for new transactions.  If no context has been set, a default
	// context.Background() is returned.
	Context() context.Context

	// WithContext returns the same session on a different default context. The
	// session is identical to the original one in all ways except for the
	// context.
	WithContext(ctx context.Context) Session

	Settings
}