Namespace: go.std.database.sql

v1.0

Contents

• Summary
• Index
• Constants
• Variables
• Functions, Macros, and Special Forms
• Types

Summary

Provides a low-level interface to the database/sql package.

Package sql provides a generic interface around SQL (or SQL-like)
databases.

The sql package must be used in conjunction with a database driver.
See https://golang.org/s/sqldrivers for a list of drivers.

Drivers that do not support context cancellation will not return until
after the query is completed.

For usage examples, see the wiki page at
https://golang.org/s/sqlwiki.

Index

• *ColumnType
• *Conn
• *DB
• *DBStats
• *IsolationLevel
• *NamedArg
• *NullBool
• *NullByte
• *NullFloat64
• *NullInt16
• *NullInt32
• *NullInt64
• *NullString
• *NullTime
• *Out
• *RawBytes
• *Row
• *Rows
• *Stmt
• *Tx
• *TxOptions
• ColumnType
• Conn
• DB
• DBStats
• Drivers
• ErrConnDone
• ErrNoRows
• ErrTxDone
• IsolationLevel
• LevelDefault
• LevelLinearizable
• LevelReadCommitted
• LevelReadUncommitted
• LevelRepeatableRead
• LevelSerializable
• LevelSnapshot
• LevelWriteCommitted
• Named
• NamedArg
• NullBool
• NullByte
• NullFloat64
• NullInt16
• NullInt32
• NullInt64
• NullString
• NullTime
• Open
• OpenDB
• Out
• RawBytes
• Register
• Result
• Row
• Rows
• Scanner
• Stmt
• Tx
• TxOptions
• arrayOfColumnType
• arrayOfConn
• arrayOfDB
• arrayOfDBStats
• arrayOfIsolationLevel
• arrayOfNamedArg
• arrayOfNullBool
• arrayOfNullByte
• arrayOfNullFloat64
• arrayOfNullInt16
• arrayOfNullInt32
• arrayOfNullInt64
• arrayOfNullString
• arrayOfNullTime
• arrayOfOut
• arrayOfRawBytes
• arrayOfResult
• arrayOfRow
• arrayOfRows
• arrayOfScanner
• arrayOfStmt
• arrayOfTx
• arrayOfTxOptions

Legend

Constant Variable Function Macro Special form Type GoVar Receiver/Method

Constants

Constants are variables with :const true in their metadata. Joker currently does not recognize them as special; as such, it allows redefining them or their values.

(None.)

Variables

• ErrConnDone

  Var v1.0

  ErrConnDone is returned by any operation that is performed on a connection
  that has already been returned to the connection pool.
  

• ErrNoRows

  Var v1.0

  ErrNoRows is returned by Scan when QueryRow doesn't return a
  row. In such a case, QueryRow returns a placeholder *Row value that
  defers this error until a Scan.
  

• ErrTxDone

  Var v1.0

  ErrTxDone is returned by any operation that is performed on a transaction
  that has already been committed or rolled back.
  

• LevelDefault

  GoObject v1.0

  Various isolation levels that drivers may support in BeginTx.
  If a driver does not support a given isolation level an error may be returned.
  
  See https://en.wikipedia.org/wiki/Isolation_(database_systems)#Isolation_levels.
  

• LevelLinearizable

  GoObject v1.0

  Various isolation levels that drivers may support in BeginTx.
  If a driver does not support a given isolation level an error may be returned.
  
  See https://en.wikipedia.org/wiki/Isolation_(database_systems)#Isolation_levels.
  

• LevelReadCommitted

  GoObject v1.0

  Various isolation levels that drivers may support in BeginTx.
  If a driver does not support a given isolation level an error may be returned.
  
  See https://en.wikipedia.org/wiki/Isolation_(database_systems)#Isolation_levels.
  

• LevelReadUncommitted

  GoObject v1.0

  Various isolation levels that drivers may support in BeginTx.
  If a driver does not support a given isolation level an error may be returned.
  
  See https://en.wikipedia.org/wiki/Isolation_(database_systems)#Isolation_levels.
  

• LevelRepeatableRead

  GoObject v1.0

  Various isolation levels that drivers may support in BeginTx.
  If a driver does not support a given isolation level an error may be returned.
  
  See https://en.wikipedia.org/wiki/Isolation_(database_systems)#Isolation_levels.
  

• LevelSerializable

  GoObject v1.0

  Various isolation levels that drivers may support in BeginTx.
  If a driver does not support a given isolation level an error may be returned.
  
  See https://en.wikipedia.org/wiki/Isolation_(database_systems)#Isolation_levels.
  

• LevelSnapshot

  GoObject v1.0

  Various isolation levels that drivers may support in BeginTx.
  If a driver does not support a given isolation level an error may be returned.
  
  See https://en.wikipedia.org/wiki/Isolation_(database_systems)#Isolation_levels.
  

• LevelWriteCommitted

  GoObject v1.0

  Various isolation levels that drivers may support in BeginTx.
  If a driver does not support a given isolation level an error may be returned.
  
  See https://en.wikipedia.org/wiki/Isolation_(database_systems)#Isolation_levels.
  

Functions, Macros, and Special Forms

• Drivers

  Function v1.0

  (Drivers)
  

  Drivers returns a sorted list of the names of the registered drivers.
  
  Go returns: []string
  
  Joker input arguments: []
  
  Joker returns: ^arrayOfString

• Named

  Function v1.0

  (Named name value)
  

  Named provides a more concise way to create NamedArg values.
  
  Example usage:
  
  db.ExecContext(ctx, `
  delete from Invoice
  where
  TimeCreated < @end
  and TimeCreated >= @start;`,
  sql.Named("start", startTime),
  sql.Named("end", endTime),
  )
  
  Go input arguments: (name string, value any)
  
  Go returns: NamedArg
  
  Joker input arguments: [^String name, ^GoObject value]
  
  Joker returns: ^NamedArg

• Open

  Function v1.0

  (Open driverName dataSourceName)
  

  Open opens a database specified by its database driver name and a
  driver-specific data source name, usually consisting of at least a
  database name and connection information.
  
  Most users will open a database via a driver-specific connection
  helper function that returns a *DB. No database drivers are included
  in the Go standard library. See https://golang.org/s/sqldrivers for
  a list of third-party drivers.
  
  Open may just validate its arguments without creating a connection
  to the database. To verify that the data source name is valid, call
  Ping.
  
  The returned DB is safe for concurrent use by multiple goroutines
  and maintains its own pool of idle connections. Thus, the Open
  function should be called just once. It is rarely necessary to
  close a DB.
  
  Go input arguments: (driverName string, dataSourceName string)
  
  Go returns: (*DB, error)
  
  Joker input arguments: [^String driverName, ^String dataSourceName]
  
  Joker returns: [^*DB, ^Error]

• OpenDB

  Function v1.0

  (OpenDB c)
  

  OpenDB opens a database using a Connector, allowing drivers to
  bypass a string based data source name.
  
  Most users will open a database via a driver-specific connection
  helper function that returns a *DB. No database drivers are included
  in the Go standard library. See https://golang.org/s/sqldrivers for
  a list of third-party drivers.
  
  OpenDB may just validate its arguments without creating a connection
  to the database. To verify that the data source name is valid, call
  Ping.
  
  The returned DB is safe for concurrent use by multiple goroutines
  and maintains its own pool of idle connections. Thus, the OpenDB
  function should be called just once. It is rarely necessary to
  close a DB.
  
  Go input arguments: (c database/sql/driver.Connector)
  
  Go returns: *DB
  
  Joker input arguments: [^go.std.database.sql.driver/Connector c]
  
  Joker returns: ^*DB

• Register

  Function v1.0

  (Register name driver)
  

  Register makes a database driver available by the provided name.
  If Register is called twice with the same name or if driver is nil,
  it panics.
  
  Go input arguments: (name string, driver database/sql/driver.Driver)
  
  Joker input arguments: [^String name, ^go.std.database.sql.driver/Driver driver]

Types

• *ColumnType

  Concrete Type v1.0

  ColumnType contains the name and type of a column.
  

• DatabaseTypeName

  Receiver for *ColumnType v1.0

  ([])
  

  DatabaseTypeName returns the database system name of the column type. If an empty
  string is returned, then the driver type name is not supported.
  Consult your driver documentation for a list of driver data types. Length specifiers
  are not included.
  Common type names include "VARCHAR", "TEXT", "NVARCHAR", "DECIMAL", "BOOL",
  "INT", and "BIGINT".
  

• DecimalSize

  Receiver for *ColumnType v1.0

  ([])
  

  DecimalSize returns the scale and precision of a decimal type.
  If not applicable or if not supported ok is false.
  

• Length

  Receiver for *ColumnType v1.0

  ([])
  

  Length returns the column type length for variable length column types such
  as text and binary field types. If the type length is unbounded the value will
  be math.MaxInt64 (any database limits will still apply).
  If the column type is not variable length, such as an int, or if not supported
  by the driver ok is false.
  

• Name

  Receiver for *ColumnType v1.0

  ([])
  

  Name returns the name or alias of the column.
  

• Nullable

  Receiver for *ColumnType v1.0

  ([])
  

  Nullable reports whether the column may be null.
  If a driver does not support this property ok will be false.
  

• ScanType

  Receiver for *ColumnType v1.0

  ([])
  

  ScanType returns a Go type suitable for scanning into using Rows.Scan.
  If a driver does not support this property ScanType will return
  the type of an empty interface.
  

• *Conn

  Concrete Type v1.0

  Conn represents a single database connection rather than a pool of database
  connections. Prefer running queries from DB unless there is a specific
  need for a continuous single database connection.
  
  A Conn must call Close to return the connection to the database pool
  and may do so concurrently with a running query.
  
  After a call to Close, all operations on the
  connection fail with ErrConnDone.
  

• BeginTx

  Receiver for *Conn v1.0

  ([ctx opts])
  

  BeginTx starts a transaction.
  
  The provided context is used until the transaction is committed or rolled back.
  If the context is canceled, the sql package will roll back
  the transaction. Tx.Commit will return an error if the context provided to
  BeginTx is canceled.
  
  The provided TxOptions is optional and may be nil if defaults should be used.
  If a non-default isolation level is used that the driver doesn't support,
  an error will be returned.
  

• Close

  Receiver for *Conn v1.0

  ([])
  

  Close returns the connection to the connection pool.
  All operations after a Close will return with ErrConnDone.
  Close is safe to call concurrently with other operations and will
  block until all other operations finish. It may be useful to first
  cancel any used context and then call close directly after.
  

• ExecContext

  Receiver for *Conn v1.0

  ([ctx query args])
  

  ExecContext executes a query without returning any rows.
  The args are for any placeholder parameters in the query.
  

• PingContext

  Receiver for *Conn v1.0

  ([ctx])
  

  PingContext verifies the connection to the database is still alive.
  

• PrepareContext

  Receiver for *Conn v1.0

  ([ctx query])
  

  PrepareContext creates a prepared statement for later queries or executions.
  Multiple queries or executions may be run concurrently from the
  returned statement.
  The caller must call the statement's Close method
  when the statement is no longer needed.
  
  The provided context is used for the preparation of the statement, not for the
  execution of the statement.
  

• QueryContext

  Receiver for *Conn v1.0

  ([ctx query args])
  

  QueryContext executes a query that returns rows, typically a SELECT.
  The args are for any placeholder parameters in the query.
  

• QueryRowContext

  Receiver for *Conn v1.0

  ([ctx query args])
  

  QueryRowContext executes a query that is expected to return at most one row.
  QueryRowContext always returns a non-nil value. Errors are deferred until
  Row's Scan method is called.
  If the query selects no rows, the *Row's Scan will return ErrNoRows.
  Otherwise, the *Row's Scan scans the first selected row and discards
  the rest.
  

• *DB

  Concrete Type v1.0

  DB is a database handle representing a pool of zero or more
  underlying connections. It's safe for concurrent use by multiple
  goroutines.
  
  The sql package creates and frees connections automatically; it
  also maintains a free pool of idle connections. If the database has
  a concept of per-connection state, such state can be reliably observed
  within a transaction (Tx) or connection (Conn). Once DB.Begin is called, the
  returned Tx is bound to a single connection. Once Commit or
  Rollback is called on the transaction, that transaction's
  connection is returned to DB's idle connection pool. The pool size
  can be controlled with SetMaxIdleConns.
  

• Begin

  Receiver for *DB v1.0

  ([])
  

  Begin starts a transaction. The default isolation level is dependent on
  the driver.
  
  Begin uses context.Background internally; to specify the context, use
  BeginTx.
  

• BeginTx

  Receiver for *DB v1.0

  ([ctx opts])
  

  BeginTx starts a transaction.
  
  The provided context is used until the transaction is committed or rolled back.
  If the context is canceled, the sql package will roll back
  the transaction. Tx.Commit will return an error if the context provided to
  BeginTx is canceled.
  
  The provided TxOptions is optional and may be nil if defaults should be used.
  If a non-default isolation level is used that the driver doesn't support,
  an error will be returned.
  

• Close

  Receiver for *DB v1.0

  ([])
  

  Close closes the database and prevents new queries from starting.
  Close then waits for all queries that have started processing on the server
  to finish.
  
  It is rare to Close a DB, as the DB handle is meant to be
  long-lived and shared between many goroutines.
  

• Conn

  Receiver for *DB v1.0

  ([ctx])
  

  Conn returns a single connection by either opening a new connection
  or returning an existing connection from the connection pool. Conn will
  block until either a connection is returned or ctx is canceled.
  Queries run on the same Conn will be run in the same database session.
  
  Every Conn must be returned to the database pool after use by
  calling Conn.Close.
  

• Driver

  Receiver for *DB v1.0

  ([])
  

  Driver returns the database's underlying driver.
  

• Exec

  Receiver for *DB v1.0

  ([query args])
  

  Exec executes a query without returning any rows.
  The args are for any placeholder parameters in the query.
  
  Exec uses context.Background internally; to specify the context, use
  ExecContext.
  

• ExecContext

  Receiver for *DB v1.0

  ([ctx query args])
  

  ExecContext executes a query without returning any rows.
  The args are for any placeholder parameters in the query.
  

• Ping

  Receiver for *DB v1.0

  ([])
  

  Ping verifies a connection to the database is still alive,
  establishing a connection if necessary.
  
  Ping uses context.Background internally; to specify the context, use
  PingContext.
  

• PingContext

  Receiver for *DB v1.0

  ([ctx])
  

  PingContext verifies a connection to the database is still alive,
  establishing a connection if necessary.
  

• Prepare

  Receiver for *DB v1.0

  ([query])
  

  Prepare creates a prepared statement for later queries or executions.
  Multiple queries or executions may be run concurrently from the
  returned statement.
  The caller must call the statement's Close method
  when the statement is no longer needed.
  
  Prepare uses context.Background internally; to specify the context, use
  PrepareContext.
  

• PrepareContext

  Receiver for *DB v1.0

  ([ctx query])
  

  PrepareContext creates a prepared statement for later queries or executions.
  Multiple queries or executions may be run concurrently from the
  returned statement.
  The caller must call the statement's Close method
  when the statement is no longer needed.
  
  The provided context is used for the preparation of the statement, not for the
  execution of the statement.
  

• Query

  Receiver for *DB v1.0

  ([query args])
  

  Query executes a query that returns rows, typically a SELECT.
  The args are for any placeholder parameters in the query.
  
  Query uses context.Background internally; to specify the context, use
  QueryContext.
  

• QueryContext

  Receiver for *DB v1.0

  ([ctx query args])
  

  QueryContext executes a query that returns rows, typically a SELECT.
  The args are for any placeholder parameters in the query.
  

• QueryRow

  Receiver for *DB v1.0

  ([query args])
  

  QueryRow executes a query that is expected to return at most one row.
  QueryRow always returns a non-nil value. Errors are deferred until
  Row's Scan method is called.
  If the query selects no rows, the *Row's Scan will return ErrNoRows.
  Otherwise, the *Row's Scan scans the first selected row and discards
  the rest.
  
  QueryRow uses context.Background internally; to specify the context, use
  QueryRowContext.
  

• QueryRowContext

  Receiver for *DB v1.0

  ([ctx query args])
  

  QueryRowContext executes a query that is expected to return at most one row.
  QueryRowContext always returns a non-nil value. Errors are deferred until
  Row's Scan method is called.
  If the query selects no rows, the *Row's Scan will return ErrNoRows.
  Otherwise, the *Row's Scan scans the first selected row and discards
  the rest.
  

• SetConnMaxIdleTime

  Receiver for *DB v1.0

  ([d])
  

  SetConnMaxIdleTime sets the maximum amount of time a connection may be idle.
  
  Expired connections may be closed lazily before reuse.
  
  If d <= 0, connections are not closed due to a connection's idle time.
  

• SetConnMaxLifetime

  Receiver for *DB v1.0

  ([d])
  

  SetConnMaxLifetime sets the maximum amount of time a connection may be reused.
  
  Expired connections may be closed lazily before reuse.
  
  If d <= 0, connections are not closed due to a connection's age.
  

• SetMaxIdleConns

  Receiver for *DB v1.0

  ([n])
  

  SetMaxIdleConns sets the maximum number of connections in the idle
  connection pool.
  
  If MaxOpenConns is greater than 0 but less than the new MaxIdleConns,
  then the new MaxIdleConns will be reduced to match the MaxOpenConns limit.
  
  If n <= 0, no idle connections are retained.
  
  The default max idle connections is currently 2. This may change in
  a future release.
  

• SetMaxOpenConns

  Receiver for *DB v1.0

  ([n])
  

  SetMaxOpenConns sets the maximum number of open connections to the database.
  
  If MaxIdleConns is greater than 0 and the new MaxOpenConns is less than
  MaxIdleConns, then MaxIdleConns will be reduced to match the new
  MaxOpenConns limit.
  
  If n <= 0, then there is no limit on the number of open connections.
  The default is 0 (unlimited).
  

• Stats

  Receiver for *DB v1.0

  ([])
  

  Stats returns database statistics.
  

• *DBStats

  Concrete Type v1.0

  DBStats contains database statistics.
  

• *IsolationLevel

  Concrete Type v1.0

  IsolationLevel is the transaction isolation level used in TxOptions.
  

• *NamedArg

  Concrete Type v1.0

  A NamedArg is a named argument. NamedArg values may be used as
  arguments to Query or Exec and bind to the corresponding named
  parameter in the SQL statement.
  
  For a more concise way to create NamedArg values, see
  the Named function.
  

• *NullBool

  Concrete Type v1.0

  NullBool represents a bool that may be null.
  NullBool implements the Scanner interface so
  it can be used as a scan destination, similar to NullString.
  

• Scan

  Receiver for *NullBool v1.0

  ([value])
  

  Scan implements the Scanner interface.
  

• *NullByte

  Concrete Type v1.0

  NullByte represents a byte that may be null.
  NullByte implements the Scanner interface so
  it can be used as a scan destination, similar to NullString.
  

• Scan

  Receiver for *NullByte v1.0

  ([value])
  

  Scan implements the Scanner interface.
  

• *NullFloat64

  Concrete Type v1.0

  NullFloat64 represents a float64 that may be null.
  NullFloat64 implements the Scanner interface so
  it can be used as a scan destination, similar to NullString.
  

• Scan

  Receiver for *NullFloat64 v1.0

  ([value])
  

  Scan implements the Scanner interface.
  

• *NullInt16

  Concrete Type v1.0

  NullInt16 represents an int16 that may be null.
  NullInt16 implements the Scanner interface so
  it can be used as a scan destination, similar to NullString.
  

• Scan

  Receiver for *NullInt16 v1.0

  ([value])
  

  Scan implements the Scanner interface.
  

• *NullInt32

  Concrete Type v1.0

  NullInt32 represents an int32 that may be null.
  NullInt32 implements the Scanner interface so
  it can be used as a scan destination, similar to NullString.
  

• Scan

  Receiver for *NullInt32 v1.0

  ([value])
  

  Scan implements the Scanner interface.
  

• *NullInt64

  Concrete Type v1.0

  NullInt64 represents an int64 that may be null.
  NullInt64 implements the Scanner interface so
  it can be used as a scan destination, similar to NullString.
  

• Scan

  Receiver for *NullInt64 v1.0

  ([value])
  

  Scan implements the Scanner interface.
  

• *NullString

  Concrete Type v1.0

  NullString represents a string that may be null.
  NullString implements the Scanner interface so
  it can be used as a scan destination:
  
  var s NullString
  err := db.QueryRow("SELECT name FROM foo WHERE id=?", id).Scan(&s)
  ...
  if s.Valid {
  // use s.String
  } else {
  // NULL value
  }
  

• Scan

  Receiver for *NullString v1.0

  ([value])
  

  Scan implements the Scanner interface.
  

• *NullTime

  Concrete Type v1.0

  NullTime represents a time.Time that may be null.
  NullTime implements the Scanner interface so
  it can be used as a scan destination, similar to NullString.
  

• Scan

  Receiver for *NullTime v1.0

  ([value])
  

  Scan implements the Scanner interface.
  

• *Out

  Concrete Type v1.0

  Out may be used to retrieve OUTPUT value parameters from stored procedures.
  
  Not all drivers and databases support OUTPUT value parameters.
  
  Example usage:
  
  var outArg string
  _, err := db.ExecContext(ctx, "ProcName", sql.Named("Arg1", sql.Out{Dest: &outArg}))
  

• *RawBytes

  Concrete Type v1.0

  RawBytes is a byte slice that holds a reference to memory owned by
  the database itself. After a Scan into a RawBytes, the slice is only
  valid until the next call to Next, Scan, or Close.
  

• *Row

  Concrete Type v1.0

  Row is the result of calling QueryRow to select a single row.
  

• Err

  Receiver for *Row v1.0

  ([])
  

  Err provides a way for wrapping packages to check for
  query errors without calling Scan.
  Err returns the error, if any, that was encountered while running the query.
  If this error is not nil, this error will also be returned from Scan.
  

• Scan

  Receiver for *Row v1.0

  ([dest])
  

  Scan copies the columns from the matched row into the values
  pointed at by dest. See the documentation on Rows.Scan for details.
  If more than one row matches the query,
  Scan uses the first row and discards the rest. If no row matches
  the query, Scan returns ErrNoRows.
  

• *Rows

  Concrete Type v1.0

  Rows is the result of a query. Its cursor starts before the first row
  of the result set. Use Next to advance from row to row.
  

• Close

  Receiver for *Rows v1.0

  ([])
  

  Close closes the Rows, preventing further enumeration. If Next is called
  and returns false and there are no further result sets,
  the Rows are closed automatically and it will suffice to check the
  result of Err. Close is idempotent and does not affect the result of Err.
  

• ColumnTypes

  Receiver for *Rows v1.0

  ([])
  

  ColumnTypes returns column information such as column type, length,
  and nullable. Some information may not be available from some drivers.
  

• Columns

  Receiver for *Rows v1.0

  ([])
  

  Columns returns the column names.
  Columns returns an error if the rows are closed.
  

• Err

  Receiver for *Rows v1.0

  ([])
  

  Err returns the error, if any, that was encountered during iteration.
  Err may be called after an explicit or implicit Close.
  

• Next

  Receiver for *Rows v1.0

  ([])
  

  Next prepares the next result row for reading with the Scan method. It
  returns true on success, or false if there is no next result row or an error
  happened while preparing it. Err should be consulted to distinguish between
  the two cases.
  
  Every call to Scan, even the first one, must be preceded by a call to Next.
  

• NextResultSet

  Receiver for *Rows v1.0

  ([])
  

  NextResultSet prepares the next result set for reading. It reports whether
  there is further result sets, or false if there is no further result set
  or if there is an error advancing to it. The Err method should be consulted
  to distinguish between the two cases.
  
  After calling NextResultSet, the Next method should always be called before
  scanning. If there are further result sets they may not have rows in the result
  set.
  

• Scan

  Receiver for *Rows v1.0

  ([dest])
  

  Scan copies the columns in the current row into the values pointed
  at by dest. The number of values in dest must be the same as the
  number of columns in Rows.
  
  Scan converts columns read from the database into the following
  common Go types and special types provided by the sql package:
  
  *string
  *[]byte
  *int, *int8, *int16, *int32, *int64
  *uint, *uint8, *uint16, *uint32, *uint64
  *bool
  *float32, *float64
  *interface{}
  *RawBytes
  *Rows (cursor value)
  any type implementing Scanner (see Scanner docs)
  
  In the most simple case, if the type of the value from the source
  column is an integer, bool or string type T and dest is of type *T,
  Scan simply assigns the value through the pointer.
  
  Scan also converts between string and numeric types, as long as no
  information would be lost. While Scan stringifies all numbers
  scanned from numeric database columns into *string, scans into
  numeric types are checked for overflow. For example, a float64 with
  value 300 or a string with value "300" can scan into a uint16, but
  not into a uint8, though float64(255) or "255" can scan into a
  uint8. One exception is that scans of some float64 numbers to
  strings may lose information when stringifying. In general, scan
  floating point columns into *float64.
  
  If a dest argument has type *[]byte, Scan saves in that argument a
  copy of the corresponding data. The copy is owned by the caller and
  can be modified and held indefinitely. The copy can be avoided by
  using an argument of type *RawBytes instead; see the documentation
  for RawBytes for restrictions on its use.
  
  If an argument has type *interface{}, Scan copies the value
  provided by the underlying driver without conversion. When scanning
  from a source value of type []byte to *interface{}, a copy of the
  slice is made and the caller owns the result.
  
  Source values of type time.Time may be scanned into values of type
  *time.Time, *interface{}, *string, or *[]byte. When converting to
  the latter two, time.RFC3339Nano is used.
  
  Source values of type bool may be scanned into types *bool,
  *interface{}, *string, *[]byte, or *RawBytes.
  
  For scanning into *bool, the source may be true, false, 1, 0, or
  string inputs parseable by strconv.ParseBool.
  
  Scan can also convert a cursor returned from a query, such as
  "select cursor(select * from my_table) from dual", into a
  *Rows value that can itself be scanned from. The parent
  select query will close any cursor *Rows if the parent *Rows is closed.
  
  If any of the first arguments implementing Scanner returns an error,
  that error will be wrapped in the returned error
  

• *Stmt

  Concrete Type v1.0

  Stmt is a prepared statement.
  A Stmt is safe for concurrent use by multiple goroutines.
  
  If a Stmt is prepared on a Tx or Conn, it will be bound to a single
  underlying connection forever. If the Tx or Conn closes, the Stmt will
  become unusable and all operations will return an error.
  If a Stmt is prepared on a DB, it will remain usable for the lifetime of the
  DB. When the Stmt needs to execute on a new underlying connection, it will
  prepare itself on the new connection automatically.
  

• Close

  Receiver for *Stmt v1.0

  ([])
  

  Close closes the statement.
  

• Exec

  Receiver for *Stmt v1.0

  ([args])
  

  Exec executes a prepared statement with the given arguments and
  returns a Result summarizing the effect of the statement.
  
  Exec uses context.Background internally; to specify the context, use
  ExecContext.
  

• ExecContext

  Receiver for *Stmt v1.0

  ([ctx args])
  

  ExecContext executes a prepared statement with the given arguments and
  returns a Result summarizing the effect of the statement.
  

• Query

  Receiver for *Stmt v1.0

  ([args])
  

  Query executes a prepared query statement with the given arguments
  and returns the query results as a *Rows.
  
  Query uses context.Background internally; to specify the context, use
  QueryContext.
  

• QueryContext

  Receiver for *Stmt v1.0

  ([ctx args])
  

  QueryContext executes a prepared query statement with the given arguments
  and returns the query results as a *Rows.
  

• QueryRow

  Receiver for *Stmt v1.0

  ([args])
  

  QueryRow executes a prepared query statement with the given arguments.
  If an error occurs during the execution of the statement, that error will
  be returned by a call to Scan on the returned *Row, which is always non-nil.
  If the query selects no rows, the *Row's Scan will return ErrNoRows.
  Otherwise, the *Row's Scan scans the first selected row and discards
  the rest.
  
  Example usage:
  
  var name string
  err := nameByUseridStmt.QueryRow(id).Scan(&name)
  
  QueryRow uses context.Background internally; to specify the context, use
  QueryRowContext.
  

• QueryRowContext

  Receiver for *Stmt v1.0

  ([ctx args])
  

  QueryRowContext executes a prepared query statement with the given arguments.
  If an error occurs during the execution of the statement, that error will
  be returned by a call to Scan on the returned *Row, which is always non-nil.
  If the query selects no rows, the *Row's Scan will return ErrNoRows.
  Otherwise, the *Row's Scan scans the first selected row and discards
  the rest.
  

• *Tx

  Concrete Type v1.0

  Tx is an in-progress database transaction.
  
  A transaction must end with a call to Commit or Rollback.
  
  After a call to Commit or Rollback, all operations on the
  transaction fail with ErrTxDone.
  
  The statements prepared for a transaction by calling
  the transaction's Prepare or Stmt methods are closed
  by the call to Commit or Rollback.
  

• Commit

  Receiver for *Tx v1.0

  ([])
  

  Commit commits the transaction.
  

• Exec

  Receiver for *Tx v1.0

  ([query args])
  

  Exec executes a query that doesn't return rows.
  For example: an INSERT and UPDATE.
  
  Exec uses context.Background internally; to specify the context, use
  ExecContext.
  

• ExecContext

  Receiver for *Tx v1.0

  ([ctx query args])
  

  ExecContext executes a query that doesn't return rows.
  For example: an INSERT and UPDATE.
  

• Prepare

  Receiver for *Tx v1.0

  ([query])
  

  Prepare creates a prepared statement for use within a transaction.
  
  The returned statement operates within the transaction and will be closed
  when the transaction has been committed or rolled back.
  
  To use an existing prepared statement on this transaction, see Tx.Stmt.
  
  Prepare uses context.Background internally; to specify the context, use
  PrepareContext.
  

• PrepareContext

  Receiver for *Tx v1.0

  ([ctx query])
  

  PrepareContext creates a prepared statement for use within a transaction.
  
  The returned statement operates within the transaction and will be closed
  when the transaction has been committed or rolled back.
  
  To use an existing prepared statement on this transaction, see Tx.Stmt.
  
  The provided context will be used for the preparation of the context, not
  for the execution of the returned statement. The returned statement
  will run in the transaction context.
  

• Query

  Receiver for *Tx v1.0

  ([query args])
  

  Query executes a query that returns rows, typically a SELECT.
  
  Query uses context.Background internally; to specify the context, use
  QueryContext.
  

• QueryContext

  Receiver for *Tx v1.0

  ([ctx query args])
  

  QueryContext executes a query that returns rows, typically a SELECT.
  

• QueryRow

  Receiver for *Tx v1.0

  ([query args])
  

  QueryRow executes a query that is expected to return at most one row.
  QueryRow always returns a non-nil value. Errors are deferred until
  Row's Scan method is called.
  If the query selects no rows, the *Row's Scan will return ErrNoRows.
  Otherwise, the *Row's Scan scans the first selected row and discards
  the rest.
  
  QueryRow uses context.Background internally; to specify the context, use
  QueryRowContext.
  

• QueryRowContext

  Receiver for *Tx v1.0

  ([ctx query args])
  

  QueryRowContext executes a query that is expected to return at most one row.
  QueryRowContext always returns a non-nil value. Errors are deferred until
  Row's Scan method is called.
  If the query selects no rows, the *Row's Scan will return ErrNoRows.
  Otherwise, the *Row's Scan scans the first selected row and discards
  the rest.
  

• Rollback

  Receiver for *Tx v1.0

  ([])
  

  Rollback aborts the transaction.
  

• Stmt

  Receiver for *Tx v1.0

  ([stmt])
  

  Stmt returns a transaction-specific prepared statement from
  an existing statement.
  
  Example:
  
  updateMoney, err := db.Prepare("UPDATE balance SET money=money+? WHERE id=?")
  ...
  tx, err := db.Begin()
  ...
  res, err := tx.Stmt(updateMoney).Exec(123.45, 98293203)
  
  The returned statement operates within the transaction and will be closed
  when the transaction has been committed or rolled back.
  
  Stmt uses context.Background internally; to specify the context, use
  StmtContext.
  

• StmtContext

  Receiver for *Tx v1.0

  ([ctx stmt])
  

  StmtContext returns a transaction-specific prepared statement from
  an existing statement.
  
  Example:
  
  updateMoney, err := db.Prepare("UPDATE balance SET money=money+? WHERE id=?")
  ...
  tx, err := db.Begin()
  ...
  res, err := tx.StmtContext(ctx, updateMoney).Exec(123.45, 98293203)
  
  The provided context is used for the preparation of the statement, not for the
  execution of the statement.
  
  The returned statement operates within the transaction and will be closed
  when the transaction has been committed or rolled back.
  

• *TxOptions

  Concrete Type v1.0

  TxOptions holds the transaction options to be used in DB.BeginTx.
  

• ColumnType

  Concrete Type v1.0

  ColumnType contains the name and type of a column.
  

• Conn

  Concrete Type v1.0

  Conn represents a single database connection rather than a pool of database
  connections. Prefer running queries from DB unless there is a specific
  need for a continuous single database connection.
  
  A Conn must call Close to return the connection to the database pool
  and may do so concurrently with a running query.
  
  After a call to Close, all operations on the
  connection fail with ErrConnDone.
  

• DB

  Concrete Type v1.0

  DB is a database handle representing a pool of zero or more
  underlying connections. It's safe for concurrent use by multiple
  goroutines.
  
  The sql package creates and frees connections automatically; it
  also maintains a free pool of idle connections. If the database has
  a concept of per-connection state, such state can be reliably observed
  within a transaction (Tx) or connection (Conn). Once DB.Begin is called, the
  returned Tx is bound to a single connection. Once Commit or
  Rollback is called on the transaction, that transaction's
  connection is returned to DB's idle connection pool. The pool size
  can be controlled with SetMaxIdleConns.
  

• DBStats

  Concrete Type v1.0

  DBStats contains database statistics.
  

• IsolationLevel

  Concrete Type v1.0

  IsolationLevel is the transaction isolation level used in TxOptions.
  

• String

  Receiver for IsolationLevel v1.0

  ([])
  

  String returns the name of the transaction isolation level.
  

• NamedArg

  Concrete Type v1.0

  A NamedArg is a named argument. NamedArg values may be used as
  arguments to Query or Exec and bind to the corresponding named
  parameter in the SQL statement.
  
  For a more concise way to create NamedArg values, see
  the Named function.
  

• NullBool

  Concrete Type v1.0

  NullBool represents a bool that may be null.
  NullBool implements the Scanner interface so
  it can be used as a scan destination, similar to NullString.
  

• Value

  Receiver for NullBool v1.0

  ([])
  

  Value implements the driver Valuer interface.
  

• NullByte

  Concrete Type v1.0

  NullByte represents a byte that may be null.
  NullByte implements the Scanner interface so
  it can be used as a scan destination, similar to NullString.
  

• Value

  Receiver for NullByte v1.0

  ([])
  

  Value implements the driver Valuer interface.
  

• NullFloat64

  Concrete Type v1.0

  NullFloat64 represents a float64 that may be null.
  NullFloat64 implements the Scanner interface so
  it can be used as a scan destination, similar to NullString.
  

• Value

  Receiver for NullFloat64 v1.0

  ([])
  

  Value implements the driver Valuer interface.
  

• NullInt16

  Concrete Type v1.0

  NullInt16 represents an int16 that may be null.
  NullInt16 implements the Scanner interface so
  it can be used as a scan destination, similar to NullString.
  

• Value

  Receiver for NullInt16 v1.0

  ([])
  

  Value implements the driver Valuer interface.
  

• NullInt32

  Concrete Type v1.0

  NullInt32 represents an int32 that may be null.
  NullInt32 implements the Scanner interface so
  it can be used as a scan destination, similar to NullString.
  

• Value

  Receiver for NullInt32 v1.0

  ([])
  

  Value implements the driver Valuer interface.
  

• NullInt64

  Concrete Type v1.0

  NullInt64 represents an int64 that may be null.
  NullInt64 implements the Scanner interface so
  it can be used as a scan destination, similar to NullString.
  

• Value

  Receiver for NullInt64 v1.0

  ([])
  

  Value implements the driver Valuer interface.
  

• NullString

  Concrete Type v1.0

  NullString represents a string that may be null.
  NullString implements the Scanner interface so
  it can be used as a scan destination:
  
  var s NullString
  err := db.QueryRow("SELECT name FROM foo WHERE id=?", id).Scan(&s)
  ...
  if s.Valid {
  // use s.String
  } else {
  // NULL value
  }
  

• Value

  Receiver for NullString v1.0

  ([])
  

  Value implements the driver Valuer interface.
  

• NullTime

  Concrete Type v1.0

  NullTime represents a time.Time that may be null.
  NullTime implements the Scanner interface so
  it can be used as a scan destination, similar to NullString.
  

• Value

  Receiver for NullTime v1.0

  ([])
  

  Value implements the driver Valuer interface.
  

• Out

  Concrete Type v1.0

  Out may be used to retrieve OUTPUT value parameters from stored procedures.
  
  Not all drivers and databases support OUTPUT value parameters.
  
  Example usage:
  
  var outArg string
  _, err := db.ExecContext(ctx, "ProcName", sql.Named("Arg1", sql.Out{Dest: &outArg}))
  

• RawBytes

  Concrete Type v1.0

  RawBytes is a byte slice that holds a reference to memory owned by
  the database itself. After a Scan into a RawBytes, the slice is only
  valid until the next call to Next, Scan, or Close.
  

• Result

  Abstract Type v1.0

  A Result summarizes an executed SQL command.
  

• LastInsertId

  Method for Result v1.0

  ([])
  

• RowsAffected

  Method for Result v1.0

  ([])
  

• Row

  Concrete Type v1.0

  Row is the result of calling QueryRow to select a single row.
  

• Rows

  Concrete Type v1.0

  Rows is the result of a query. Its cursor starts before the first row
  of the result set. Use Next to advance from row to row.
  

• Scanner

  Abstract Type v1.0

  Scanner is an interface used by Scan.
  

• Scan

  Method for Scanner v1.0

  ([src])
  

• Stmt

  Concrete Type v1.0

  Stmt is a prepared statement.
  A Stmt is safe for concurrent use by multiple goroutines.
  
  If a Stmt is prepared on a Tx or Conn, it will be bound to a single
  underlying connection forever. If the Tx or Conn closes, the Stmt will
  become unusable and all operations will return an error.
  If a Stmt is prepared on a DB, it will remain usable for the lifetime of the
  DB. When the Stmt needs to execute on a new underlying connection, it will
  prepare itself on the new connection automatically.
  

• Tx

  Concrete Type v1.0

  Tx is an in-progress database transaction.
  
  A transaction must end with a call to Commit or Rollback.
  
  After a call to Commit or Rollback, all operations on the
  transaction fail with ErrTxDone.
  
  The statements prepared for a transaction by calling
  the transaction's Prepare or Stmt methods are closed
  by the call to Commit or Rollback.
  

• TxOptions

  Concrete Type v1.0

  TxOptions holds the transaction options to be used in DB.BeginTx.
  

• arrayOfColumnType

  Concrete Type v1.0

  ColumnType contains the name and type of a column.
  

• arrayOfConn

  Concrete Type v1.0

  Conn represents a single database connection rather than a pool of database
  connections. Prefer running queries from DB unless there is a specific
  need for a continuous single database connection.
  
  A Conn must call Close to return the connection to the database pool
  and may do so concurrently with a running query.
  
  After a call to Close, all operations on the
  connection fail with ErrConnDone.
  

• arrayOfDB

  Concrete Type v1.0

  DB is a database handle representing a pool of zero or more
  underlying connections. It's safe for concurrent use by multiple
  goroutines.
  
  The sql package creates and frees connections automatically; it
  also maintains a free pool of idle connections. If the database has
  a concept of per-connection state, such state can be reliably observed
  within a transaction (Tx) or connection (Conn). Once DB.Begin is called, the
  returned Tx is bound to a single connection. Once Commit or
  Rollback is called on the transaction, that transaction's
  connection is returned to DB's idle connection pool. The pool size
  can be controlled with SetMaxIdleConns.
  

• arrayOfDBStats

  Concrete Type v1.0

  DBStats contains database statistics.
  

• arrayOfIsolationLevel

  Concrete Type v1.0

  IsolationLevel is the transaction isolation level used in TxOptions.
  

• arrayOfNamedArg

  Concrete Type v1.0

  A NamedArg is a named argument. NamedArg values may be used as
  arguments to Query or Exec and bind to the corresponding named
  parameter in the SQL statement.
  
  For a more concise way to create NamedArg values, see
  the Named function.
  

• arrayOfNullBool

  Concrete Type v1.0

  NullBool represents a bool that may be null.
  NullBool implements the Scanner interface so
  it can be used as a scan destination, similar to NullString.
  

• arrayOfNullByte

  Concrete Type v1.0

  NullByte represents a byte that may be null.
  NullByte implements the Scanner interface so
  it can be used as a scan destination, similar to NullString.
  

• arrayOfNullFloat64

  Concrete Type v1.0

  NullFloat64 represents a float64 that may be null.
  NullFloat64 implements the Scanner interface so
  it can be used as a scan destination, similar to NullString.
  

• arrayOfNullInt16

  Concrete Type v1.0

  NullInt16 represents an int16 that may be null.
  NullInt16 implements the Scanner interface so
  it can be used as a scan destination, similar to NullString.
  

• arrayOfNullInt32

  Concrete Type v1.0

  NullInt32 represents an int32 that may be null.
  NullInt32 implements the Scanner interface so
  it can be used as a scan destination, similar to NullString.
  

• arrayOfNullInt64

  Concrete Type v1.0

  NullInt64 represents an int64 that may be null.
  NullInt64 implements the Scanner interface so
  it can be used as a scan destination, similar to NullString.
  

• arrayOfNullString

  Concrete Type v1.0

  NullString represents a string that may be null.
  NullString implements the Scanner interface so
  it can be used as a scan destination:
  
  var s NullString
  err := db.QueryRow("SELECT name FROM foo WHERE id=?", id).Scan(&s)
  ...
  if s.Valid {
  // use s.String
  } else {
  // NULL value
  }
  

• arrayOfNullTime

  Concrete Type v1.0

  NullTime represents a time.Time that may be null.
  NullTime implements the Scanner interface so
  it can be used as a scan destination, similar to NullString.
  

• arrayOfOut

  Concrete Type v1.0

  Out may be used to retrieve OUTPUT value parameters from stored procedures.
  
  Not all drivers and databases support OUTPUT value parameters.
  
  Example usage:
  
  var outArg string
  _, err := db.ExecContext(ctx, "ProcName", sql.Named("Arg1", sql.Out{Dest: &outArg}))
  

• arrayOfRawBytes

  Concrete Type v1.0

  RawBytes is a byte slice that holds a reference to memory owned by
  the database itself. After a Scan into a RawBytes, the slice is only
  valid until the next call to Next, Scan, or Close.
  

• arrayOfResult

  Concrete Type v1.0

  A Result summarizes an executed SQL command.
  

• arrayOfRow

  Concrete Type v1.0

  Row is the result of calling QueryRow to select a single row.
  

• arrayOfRows

  Concrete Type v1.0

  Rows is the result of a query. Its cursor starts before the first row
  of the result set. Use Next to advance from row to row.
  

• arrayOfScanner

  Concrete Type v1.0

  Scanner is an interface used by Scan.
  

• arrayOfStmt

  Concrete Type v1.0

  Stmt is a prepared statement.
  A Stmt is safe for concurrent use by multiple goroutines.
  
  If a Stmt is prepared on a Tx or Conn, it will be bound to a single
  underlying connection forever. If the Tx or Conn closes, the Stmt will
  become unusable and all operations will return an error.
  If a Stmt is prepared on a DB, it will remain usable for the lifetime of the
  DB. When the Stmt needs to execute on a new underlying connection, it will
  prepare itself on the new connection automatically.
  

• arrayOfTx

  Concrete Type v1.0

  Tx is an in-progress database transaction.
  
  A transaction must end with a call to Commit or Rollback.
  
  After a call to Commit or Rollback, all operations on the
  transaction fail with ErrTxDone.
  
  The statements prepared for a transaction by calling
  the transaction's Prepare or Stmt methods are closed
  by the call to Commit or Rollback.
  

• arrayOfTxOptions

  Concrete Type v1.0

  TxOptions holds the transaction options to be used in DB.BeginTx.