package driver
Import Path
database/sql/driver (on go.dev)
Dependency Relation
imports 6 packages, and imported by one package
Involved Source Files
Package driver defines interfaces to be implemented by database
drivers as used by package sql.
Most code should use package sql.
The driver interface has evolved over time. Drivers should implement
Connector and DriverContext interfaces.
The Connector.Connect and Driver.Open methods should never return ErrBadConn.
ErrBadConn should only be returned from Validator, SessionResetter, or
a query method if the connection is already in an invalid (e.g. closed) state.
All Conn implementations should implement the following interfaces:
Pinger, SessionResetter, and Validator.
If named parameters or context are supported, the driver's Conn should implement:
ExecerContext, QueryerContext, ConnPrepareContext, and ConnBeginTx.
To support custom data types, implement NamedValueChecker. NamedValueChecker
also allows queries to accept per-query options as a parameter by returning
ErrRemoveArgument from CheckNamedValue.
If multiple result sets are supported, Rows should implement RowsNextResultSet.
If the driver knows how to describe the types present in the returned result
it should implement the following interfaces: RowsColumnTypeScanType,
RowsColumnTypeDatabaseTypeName, RowsColumnTypeLength, RowsColumnTypeNullable,
and RowsColumnTypePrecisionScale. A given row value may also return a Rows
type, which may represent a database cursor value.
Before a connection is returned to the connection pool after use, IsValid is
called if implemented. Before a connection is reused for another query,
ResetSession is called if implemented. If a connection is never returned to the
connection pool but immediately reused, then ResetSession is called prior to
reuse but IsValid is not called.
types.go
Package-Level Type Names (total 42, in which 36 are exported)
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.
Deprecated: Drivers should implement NamedValueChecker.
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.
Conn is a connection to a database. It is not used concurrently
by multiple goroutines.
Conn is assumed to be stateful.
Begin starts and returns a new transaction.
Deprecated: Drivers should implement ConnBeginTx instead (or additionally).
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.
Drivers must ensure all network calls made by Close
do not block indefinitely (e.g. apply a timeout).
Prepare returns a prepared statement, bound to this connection.
T : io.Closer
func Connector.Connect(context.Context) (Conn, error)
func Driver.Open(name string) (Conn, error)
ConnBeginTx enhances the Conn interface with context and TxOptions.
BeginTx starts and returns a new transaction.
If the context is canceled by the user the sql package will
call Tx.Rollback before discarding and closing the connection.
This must check opts.Isolation to determine if there is a set
isolation level. If the driver does not support a non-default
level and one is set or if there is a non-default isolation level
that is not supported, an error must be returned.
This must also check opts.ReadOnly to determine if the read-only
value is true to either set the read-only transaction property if supported
or return an error if it is not supported.
A Connector represents a driver in a fixed configuration
and can create any number of equivalent Conns for use
by multiple goroutines.
A Connector can be passed to sql.OpenDB, to allow drivers
to implement their own sql.DB constructors, or returned by
DriverContext's OpenConnector method, to allow drivers
access to context and to avoid repeated parsing of driver
configuration.
Connect returns a connection to the database.
Connect 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 provided context.Context is for dialing purposes only
(see net.DialContext) and should not be stored or used for
other purposes. A default timeout should still be used
when dialing as a connection pool may call Connect
asynchronously to any query.
The returned connection is only used by one goroutine at a
time.
Driver returns the underlying Driver of the Connector,
mainly to maintain compatibility with the Driver method
on sql.DB.
func DriverContext.OpenConnector(name string) (Connector, error)
ConnPrepareContext enhances the Conn interface with context.
PrepareContext returns a prepared statement, bound to this connection.
context is for the preparation of the statement,
it must not store the context within the statement itself.
Driver is the interface that must be implemented by a database
driver.
Database drivers may implement DriverContext for access
to contexts and to parse the name only once for a pool of connections,
instead of once per connection.
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.
func Connector.Driver() Driver
If a Driver implements DriverContext, then sql.DB will call
OpenConnector to obtain a Connector and then invoke
that Connector's Connect method to obtain each needed connection,
instead of invoking the Driver's Open method for each connection.
The two-step sequence allows drivers to parse the name just once
and also provides access to per-Conn contexts.
OpenConnector must parse the name in the same format that Driver.Open
parses the name parameter.
Execer is an optional interface that may be implemented by a Conn.
If a Conn implements neither ExecerContext nor Execer,
the sql package's DB.Exec will first prepare a query, execute the statement,
and then close the statement.
Exec may return ErrSkip.
Deprecated: Drivers should implement ExecerContext instead.
( T) Exec(query string, args []Value) (Result, error)
ExecerContext is an optional interface that may be implemented by a Conn.
If a Conn does not implement ExecerContext, the sql package's DB.Exec
will fall back to Execer; if the Conn does not implement Execer either,
DB.Exec will first prepare a query, execute the statement, and then
close the statement.
ExecerContext may return ErrSkip.
ExecerContext must honor the context timeout and return when the context is canceled.
( T) ExecContext(ctx context.Context, query string, args []NamedValue) (Result, error)
IsolationLevel is the transaction isolation level stored in TxOptions.
This type should be considered identical to sql.IsolationLevel along
with any values defined on it.
NamedValue holds both the value name and value.
If the Name is not empty it should be used for the parameter identifier and
not the ordinal position.
Name will not have a symbol prefix.
Ordinal position of the parameter starting from one and is always set.
Value is the parameter value.
func ExecerContext.ExecContext(ctx context.Context, query string, args []NamedValue) (Result, error)
func NamedValueChecker.CheckNamedValue(*NamedValue) error
func QueryerContext.QueryContext(ctx context.Context, query string, args []NamedValue) (Rows, error)
func StmtExecContext.ExecContext(ctx context.Context, args []NamedValue) (Result, error)
func StmtQueryContext.QueryContext(ctx context.Context, args []NamedValue) (Rows, error)
NamedValueChecker may be optionally implemented by Conn or Stmt. It provides
the driver more control to handle Go and database types beyond the default
Values types allowed.
The sql package checks for value checkers in the following order,
stopping at the first found match: Stmt.NamedValueChecker, Conn.NamedValueChecker,
Stmt.ColumnConverter, DefaultParameterConverter.
If CheckNamedValue returns ErrRemoveArgument, the NamedValue will not be included in
the final query arguments. This may be used to pass special options to
the query itself.
If ErrSkip is returned the column converter error checking
path is used for the argument. Drivers may wish to return ErrSkip after
they have exhausted their own special cases.
CheckNamedValue is called before passing arguments to the driver
and is called in place of any ColumnConverter. CheckNamedValue must do type
validation and conversion as appropriate for the driver.
NotNull is a type that implements ValueConverter by disallowing nil
values but otherwise delegating to another ValueConverter.
Converter ValueConverter
( T) ConvertValue(v interface{}) (Value, error)
T : ValueConverter
Null is a type that implements ValueConverter by allowing nil
values but otherwise delegating to another ValueConverter.
Converter ValueConverter
( T) ConvertValue(v interface{}) (Value, error)
T : ValueConverter
Pinger is an optional interface that may be implemented by a Conn.
If a Conn does not implement Pinger, the sql package's DB.Ping and
DB.PingContext will check if there is at least one Conn available.
If Conn.Ping returns ErrBadConn, DB.Ping and DB.PingContext will remove
the Conn from pool.
( T) Ping(ctx context.Context) error
*net/http.http2ClientConn
Queryer is an optional interface that may be implemented by a Conn.
If a Conn implements neither QueryerContext nor Queryer,
the sql package's DB.Query will first prepare a query, execute the statement,
and then close the statement.
Query may return ErrSkip.
Deprecated: Drivers should implement QueryerContext instead.
( T) Query(query string, args []Value) (Rows, error)
QueryerContext is an optional interface that may be implemented by a Conn.
If a Conn does not implement QueryerContext, the sql package's DB.Query
will fall back to Queryer; if the Conn does not implement Queryer either,
DB.Query will first prepare a query, execute the statement, and then
close the statement.
QueryerContext may return ErrSkip.
QueryerContext must honor the context timeout and return when the context is canceled.
( T) QueryContext(ctx context.Context, query string, args []NamedValue) (Rows, error)
Result is the result of a query execution.
LastInsertId returns the database's auto-generated ID
after, for example, an INSERT into a table with primary
key.
RowsAffected returns the number of rows affected by the
query.
RowsAffected
noRows
func Execer.Exec(query string, args []Value) (Result, error)
func ExecerContext.ExecContext(ctx context.Context, query string, args []NamedValue) (Result, error)
func Stmt.Exec(args []Value) (Result, error)
func StmtExecContext.ExecContext(ctx context.Context, args []NamedValue) (Result, error)
Rows is an iterator over an executed query's results.
Close closes the rows iterator.
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.
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.
Next should return io.EOF when there are no more rows.
The dest should not be written to outside of Next. Care
should be taken when closing Rows not to modify
a buffer held in dest.
RowsColumnTypeDatabaseTypeName (interface)
RowsColumnTypeLength (interface)
RowsColumnTypeNullable (interface)
RowsColumnTypePrecisionScale (interface)
RowsColumnTypeScanType (interface)
RowsNextResultSet (interface)
T : io.Closer
func Queryer.Query(query string, args []Value) (Rows, error)
func QueryerContext.QueryContext(ctx context.Context, query string, args []NamedValue) (Rows, error)
func Stmt.Query(args []Value) (Rows, error)
func StmtQueryContext.QueryContext(ctx context.Context, args []NamedValue) (Rows, error)
RowsAffected implements Result for an INSERT or UPDATE operation
which mutates a number of rows.
( T) LastInsertId() (int64, error)
( T) RowsAffected() (int64, error)
T : Result
RowsColumnTypeDatabaseTypeName may be implemented by Rows. It should return the
database system type name without the length. Type names should be uppercase.
Examples of returned types: "VARCHAR", "NVARCHAR", "VARCHAR2", "CHAR", "TEXT",
"DECIMAL", "SMALLINT", "INT", "BIGINT", "BOOL", "[]BIGINT", "JSONB", "XML",
"TIMESTAMP".
Close closes the rows iterator.
( T) ColumnTypeDatabaseTypeName(index int) string
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.
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.
Next should return io.EOF when there are no more rows.
The dest should not be written to outside of Next. Care
should be taken when closing Rows not to modify
a buffer held in dest.
T : Rows
T : io.Closer
RowsColumnTypeLength may be implemented by Rows. It should return the length
of the column type if the column is a variable length type. If the column is
not a variable length type ok should return false.
If length is not limited other than system limits, it should return math.MaxInt64.
The following are examples of returned values for various types:
TEXT (math.MaxInt64, true)
varchar(10) (10, true)
nvarchar(10) (10, true)
decimal (0, false)
int (0, false)
bytea(30) (30, true)
Close closes the rows iterator.
( T) ColumnTypeLength(index int) (length int64, ok bool)
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.
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.
Next should return io.EOF when there are no more rows.
The dest should not be written to outside of Next. Care
should be taken when closing Rows not to modify
a buffer held in dest.
T : Rows
T : io.Closer
RowsColumnTypeNullable may be implemented by Rows. The nullable value should
be true if it is known the column may be null, or false if the column is known
to be not nullable.
If the column nullability is unknown, ok should be false.
Close closes the rows iterator.
( T) ColumnTypeNullable(index int) (nullable, ok bool)
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.
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.
Next should return io.EOF when there are no more rows.
The dest should not be written to outside of Next. Care
should be taken when closing Rows not to modify
a buffer held in dest.
T : Rows
T : io.Closer
RowsColumnTypePrecisionScale may be implemented by Rows. It should return
the precision and scale for decimal types. If not applicable, ok should be false.
The following are examples of returned values for various types:
decimal(38, 4) (38, 4, true)
int (0, 0, false)
decimal (math.MaxInt64, math.MaxInt64, true)
Close closes the rows iterator.
( T) ColumnTypePrecisionScale(index int) (precision, scale int64, ok bool)
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.
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.
Next should return io.EOF when there are no more rows.
The dest should not be written to outside of Next. Care
should be taken when closing Rows not to modify
a buffer held in dest.
T : Rows
T : io.Closer
RowsColumnTypeScanType may be implemented by Rows. It should return
the value type that can be used to scan types into. For example, the database
column type "bigint" this should return "reflect.TypeOf(int64(0))".
Close closes the rows iterator.
( T) ColumnTypeScanType(index int) reflect.Type
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.
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.
Next should return io.EOF when there are no more rows.
The dest should not be written to outside of Next. Care
should be taken when closing Rows not to modify
a buffer held in dest.
T : Rows
T : io.Closer
RowsNextResultSet extends the Rows interface by providing a way to signal
the driver to advance to the next result set.
Close closes the rows iterator.
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.
HasNextResultSet is called at the end of the current result set and
reports whether there is another result set after the current one.
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.
Next should return io.EOF when there are no more rows.
The dest should not be written to outside of Next. Care
should be taken when closing Rows not to modify
a buffer held in dest.
NextResultSet advances the driver to the next result set even
if there are remaining rows in the current result set.
NextResultSet should return io.EOF when there are no more result sets.
T : Rows
T : io.Closer
SessionResetter may be implemented by Conn to allow drivers to reset the
session state associated with the connection and to signal a bad connection.
ResetSession is called prior to executing a query on the connection
if the connection has been used before. If the driver returns ErrBadConn
the connection is discarded.
Stmt is a prepared statement. It is bound to a Conn and not
used by multiple goroutines concurrently.
Close closes the statement.
As of Go 1.1, a Stmt will not be closed if it's in use
by any queries.
Drivers must ensure all network calls made by Close
do not block indefinitely (e.g. apply a timeout).
Exec executes a query that doesn't return rows, such
as an INSERT or UPDATE.
Deprecated: Drivers should implement StmtExecContext instead (or additionally).
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.
Query executes a query that may return rows, such as a
SELECT.
Deprecated: Drivers should implement StmtQueryContext instead (or additionally).
T : io.Closer
func Conn.Prepare(query string) (Stmt, error)
func ConnPrepareContext.PrepareContext(ctx context.Context, query string) (Stmt, error)
StmtExecContext enhances the Stmt interface by providing Exec with context.
ExecContext executes a query that doesn't return rows, such
as an INSERT or UPDATE.
ExecContext must honor the context timeout and return when it is canceled.
StmtQueryContext enhances the Stmt interface by providing Query with context.
QueryContext executes a query that may return rows, such as a
SELECT.
QueryContext must honor the context timeout and return when it is canceled.
Tx is a transaction.
( T) Commit() error
( T) Rollback() error
func Conn.Begin() (Tx, error)
func ConnBeginTx.BeginTx(ctx context.Context, opts TxOptions) (Tx, error)
TxOptions holds the transaction options.
This type should be considered identical to sql.TxOptions.
Isolation IsolationLevel
ReadOnly bool
func ConnBeginTx.BeginTx(ctx context.Context, opts TxOptions) (Tx, error)
Validator may be implemented by Conn to allow drivers to
signal if a connection is valid or if it should be discarded.
If implemented, drivers may return the underlying error from queries,
even if the connection should be discarded by the connection pool.
IsValid is called prior to placing the connection into the
connection pool. The connection will be discarded if false is returned.
*github.com/nutanix-core/ntnx-api-golang-sdk-external/files-go-client/v4/models/common/v1/config.IPAddress
*github.com/nutanix-core/ntnx-api-golang-sdk-external/files-go-client/v4/models/common/v1/config.IPAddressOrFQDN
internal/reflectlite.Value
reflect.Value
Value is a value that drivers must be able to handle.
It is either nil, a type handled by a database driver's NamedValueChecker
interface, or an instance of one of these types:
int64
float64
bool
[]byte
string
time.Time
If the driver supports cursors, a returned Value may also implement the Rows interface
in this package. This is used, for example, when a user selects a cursor
such as "select cursor(select * from my_table) from dual". If the Rows
from the select is closed, the cursor Rows will also be closed.
func NotNull.ConvertValue(v interface{}) (Value, error)
func Null.ConvertValue(v interface{}) (Value, error)
func ValueConverter.ConvertValue(v interface{}) (Value, error)
func Valuer.Value() (Value, error)
func github.com/google/uuid.NullUUID.Value() (Value, error)
func github.com/google/uuid.UUID.Value() (Value, error)
func callValuerValue(vr Valuer) (v Value, err error)
func Execer.Exec(query string, args []Value) (Result, error)
func Queryer.Query(query string, args []Value) (Rows, error)
func Rows.Next(dest []Value) error
func RowsColumnTypeDatabaseTypeName.Next(dest []Value) error
func RowsColumnTypeLength.Next(dest []Value) error
func RowsColumnTypeNullable.Next(dest []Value) error
func RowsColumnTypePrecisionScale.Next(dest []Value) error
func RowsColumnTypeScanType.Next(dest []Value) error
func RowsNextResultSet.Next(dest []Value) error
func Stmt.Exec(args []Value) (Result, error)
func Stmt.Query(args []Value) (Rows, error)
ValueConverter is the interface providing the ConvertValue method.
Various implementations of ValueConverter are provided by the
driver package to provide consistent implementations of conversions
between drivers. The ValueConverters have several uses:
* converting from the Value types as provided by the sql package
into a database table's specific column type and making sure it
fits, such as making sure a particular int64 fits in a
table's uint16 column.
* converting a value as given from the database into one of the
driver Value types.
* by the sql package, for converting from a driver's Value type
to a user's type in a scan.
ConvertValue converts a value to a driver Value.
NotNull
Null
boolType
defaultConverter
int32Type
stringType
func ColumnConverter.ColumnConverter(idx int) ValueConverter
Valuer is the interface providing the Value method.
Types implementing Valuer interface are able to convert
themselves to a driver Value.
Value returns a driver Value.
Value must not panic.
github.com/google/uuid.NullUUID
github.com/google/uuid.UUID
func callValuerValue(vr Valuer) (v Value, err error)
Package-Level Functions (total 3, in which 2 are exported)
IsScanValue is equivalent to IsValue.
It exists for compatibility.
IsValue reports whether v is a valid Value parameter type.
Package-Level Variables (total 9, in which 8 are exported)
Bool is a ValueConverter that converts input values to bools.
The conversion rules are:
- booleans are returned unchanged
- for integer types,
1 is true
0 is false,
other integers are an error
- for strings and []byte, same rules as strconv.ParseBool
- all other types are an error
DefaultParameterConverter is the default implementation of
ValueConverter that's used when a Stmt doesn't implement
ColumnConverter.
DefaultParameterConverter returns its argument directly if
IsValue(arg). Otherwise, if the argument implements Valuer, its
Value method is used to return a Value. As a fallback, the provided
argument's underlying type is used to convert it to a Value:
underlying integer types are converted to int64, floats to float64,
bool, string, and []byte to themselves. If the argument is a nil
pointer, ConvertValue returns a nil Value. If the argument is a
non-nil pointer, it is dereferenced and ConvertValue is called
recursively. Other types are an error.
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.
ErrRemoveArgument may be returned from NamedValueChecker to instruct the
sql package to not pass the argument to the driver query interface.
Return when accepting query specific options or structures that aren't
SQL query arguments.
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.
Int32 is a ValueConverter that converts input values to int64,
respecting the limits of an int32 value.
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.
String is a ValueConverter that converts its input to a string.
If the value is already a string or []byte, it's unchanged.
If the value is of another type, conversion to string is done
with fmt.Sprintf("%v", v).