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diff --git a/src/database/sql/driver/driver.go b/src/database/sql/driver/driver.go
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+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package driver defines interfaces to be implemented by database
+// drivers as used by package sql.
+//
+// Most code should use package sql.
+package driver
+
+import "errors"
+
+// Value is a value that drivers must be able to handle.
+// It is either nil or an instance of one of these types:
+//
+//   int64
+//   float64
+//   bool
+//   []byte
+//   string   [*] everywhere except from Rows.Next.
+//   time.Time
+type Value interface{}
+
+// Driver is the interface that must be implemented by a database
+// driver.
+type Driver interface {
+	// Open returns a new connection to the database.
+	// The name is a string in a driver-specific format.
+	//
+	// Open may return a cached connection (one previously
+	// closed), but doing so is unnecessary; the sql package
+	// maintains a pool of idle connections for efficient re-use.
+	//
+	// The returned connection is only used by one goroutine at a
+	// time.
+	Open(name string) (Conn, error)
+}
+
+// ErrSkip may be returned by some optional interfaces' methods to
+// indicate at runtime that the fast path is unavailable and the sql
+// package should continue as if the optional interface was not
+// implemented. ErrSkip is only supported where explicitly
+// documented.
+var ErrSkip = errors.New("driver: skip fast-path; continue as if unimplemented")
+
+// ErrBadConn should be returned by a driver to signal to the sql
+// package that a driver.Conn is in a bad state (such as the server
+// having earlier closed the connection) and the sql package should
+// retry on a new connection.
+//
+// To prevent duplicate operations, ErrBadConn should NOT be returned
+// if there's a possibility that the database server might have
+// performed the operation. Even if the server sends back an error,
+// you shouldn't return ErrBadConn.
+var ErrBadConn = errors.New("driver: bad connection")
+
+// Execer is an optional interface that may be implemented by a Conn.
+//
+// If a Conn does not implement Execer, the sql package's DB.Exec will
+// first prepare a query, execute the statement, and then close the
+// statement.
+//
+// Exec may return ErrSkip.
+type Execer interface {
+	Exec(query string, args []Value) (Result, error)
+}
+
+// Queryer is an optional interface that may be implemented by a Conn.
+//
+// If a Conn does not implement Queryer, the sql package's DB.Query will
+// first prepare a query, execute the statement, and then close the
+// statement.
+//
+// Query may return ErrSkip.
+type Queryer interface {
+	Query(query string, args []Value) (Rows, error)
+}
+
+// Conn is a connection to a database. It is not used concurrently
+// by multiple goroutines.
+//
+// Conn is assumed to be stateful.
+type Conn interface {
+	// Prepare returns a prepared statement, bound to this connection.
+	Prepare(query string) (Stmt, error)
+
+	// Close invalidates and potentially stops any current
+	// prepared statements and transactions, marking this
+	// connection as no longer in use.
+	//
+	// Because the sql package maintains a free pool of
+	// connections and only calls Close when there's a surplus of
+	// idle connections, it shouldn't be necessary for drivers to
+	// do their own connection caching.
+	Close() error
+
+	// Begin starts and returns a new transaction.
+	Begin() (Tx, error)
+}
+
+// Result is the result of a query execution.
+type Result interface {
+	// LastInsertId returns the database's auto-generated ID
+	// after, for example, an INSERT into a table with primary
+	// key.
+	LastInsertId() (int64, error)
+
+	// RowsAffected returns the number of rows affected by the
+	// query.
+	RowsAffected() (int64, error)
+}
+
+// Stmt is a prepared statement. It is bound to a Conn and not
+// used by multiple goroutines concurrently.
+type Stmt interface {
+	// Close closes the statement.
+	//
+	// As of Go 1.1, a Stmt will not be closed if it's in use
+	// by any queries.
+	Close() error
+
+	// NumInput returns the number of placeholder parameters.
+	//
+	// If NumInput returns >= 0, the sql package will sanity check
+	// argument counts from callers and return errors to the caller
+	// before the statement's Exec or Query methods are called.
+	//
+	// NumInput may also return -1, if the driver doesn't know
+	// its number of placeholders. In that case, the sql package
+	// will not sanity check Exec or Query argument counts.
+	NumInput() int
+
+	// Exec executes a query that doesn't return rows, such
+	// as an INSERT or UPDATE.
+	Exec(args []Value) (Result, error)
+
+	// Query executes a query that may return rows, such as a
+	// SELECT.
+	Query(args []Value) (Rows, error)
+}
+
+// ColumnConverter may be optionally implemented by Stmt if the
+// statement is aware of its own columns' types and can convert from
+// any type to a driver Value.
+type ColumnConverter interface {
+	// ColumnConverter returns a ValueConverter for the provided
+	// column index.  If the type of a specific column isn't known
+	// or shouldn't be handled specially, DefaultValueConverter
+	// can be returned.
+	ColumnConverter(idx int) ValueConverter
+}
+
+// Rows is an iterator over an executed query's results.
+type Rows interface {
+	// Columns returns the names of the columns. The number of
+	// columns of the result is inferred from the length of the
+	// slice.  If a particular column name isn't known, an empty
+	// string should be returned for that entry.
+	Columns() []string
+
+	// Close closes the rows iterator.
+	Close() error
+
+	// Next is called to populate the next row of data into
+	// the provided slice. The provided slice will be the same
+	// size as the Columns() are wide.
+	//
+	// The dest slice may be populated only with
+	// a driver Value type, but excluding string.
+	// All string values must be converted to []byte.
+	//
+	// Next should return io.EOF when there are no more rows.
+	Next(dest []Value) error
+}
+
+// Tx is a transaction.
+type Tx interface {
+	Commit() error
+	Rollback() error
+}
+
+// RowsAffected implements Result for an INSERT or UPDATE operation
+// which mutates a number of rows.
+type RowsAffected int64
+
+var _ Result = RowsAffected(0)
+
+func (RowsAffected) LastInsertId() (int64, error) {
+	return 0, errors.New("no LastInsertId available")
+}
+
+func (v RowsAffected) RowsAffected() (int64, error) {
+	return int64(v), nil
+}
+
+// ResultNoRows is a pre-defined Result for drivers to return when a DDL
+// command (such as a CREATE TABLE) succeeds. It returns an error for both
+// LastInsertId and RowsAffected.
+var ResultNoRows noRows
+
+type noRows struct{}
+
+var _ Result = noRows{}
+
+func (noRows) LastInsertId() (int64, error) {
+	return 0, errors.New("no LastInsertId available after DDL statement")
+}
+
+func (noRows) RowsAffected() (int64, error) {
+	return 0, errors.New("no RowsAffected available after DDL statement")
+}