split perform_query and perform_exec

add DB::ExecResult to have a concurrency safety exec result
remove connection string from abstract DB::Connection
This commit is contained in:
Brian J. Cardiff 2016-02-01 23:02:04 -03:00
parent 67fe5c9aae
commit 3598dddb65
7 changed files with 47 additions and 57 deletions

View file

@ -36,24 +36,10 @@ describe DB do
end
end
it "exec should close statement" do
with_dummy do |db|
db.exec ""
DummyDriver::DummyResultSet.last_result_set.closed?.should be_true
end
end
it "scalar should close statement" do
with_dummy do |db|
db.scalar "1"
DummyDriver::DummyResultSet.last_result_set.closed?.should be_true
end
end
it "exec should perform statement" do
with_dummy do |db|
db.exec ""
DummyDriver::DummyResultSet.last_result_set.executed?.should be_true
end
end
end

View file

@ -6,6 +6,11 @@ class DummyDriver < DB::Driver
end
class DummyConnection < DB::Connection
getter connection_string
def initialize(@connection_string)
end
def prepare(query)
DummyStatement.new(self, query)
end
@ -26,12 +31,21 @@ class DummyDriver < DB::Driver
super(driver)
end
protected def perform(args : Slice(DB::Any))
protected def perform_query(args : Slice(DB::Any))
set_params args
DummyResultSet.new self, @query
end
protected def perform_exec(args : Slice(DB::Any))
set_params args
DB::ExecResult.new 0, 0
end
private def set_params(args)
@params.clear
args.each_with_index do |arg, index|
@params[index] = arg
end
DummyResultSet.new self, @query
end
end
@ -42,7 +56,6 @@ class DummyDriver < DB::Driver
super(statement)
@iterator = query.split.map { |r| r.split(',') }.to_a.each
@executed = false
@@last_result_set = self
end
@ -50,12 +63,7 @@ class DummyDriver < DB::Driver
@@last_result_set.not_nil!
end
def executed?
@executed
end
def move_next
@executed = true
@iterator.next.tap do |n|
return false if n.is_a?(Iterator::Stop)
@values = n.each

View file

@ -17,12 +17,8 @@ module DB
abstract class Connection
# TODO add IDLE status, for connection ppool management.
getter connection_string # TODO Remove
@closed = false
def initialize(@connection_string) # TODO Remove
end
# Closes this connection.
def close
raise "Connection already closed" if @closed # TODO make it no fail if closed
@ -45,10 +41,6 @@ module DB
include QueryMethods
# Returns the last inserted id through this connection.
abstract def last_insert_id : Int64 # TODO move to ExecResult record. plano. with last_rows. eagerly askit.
protected abstract def perform_close # TODO do_close
end
end

View file

@ -67,8 +67,10 @@ module DB
# See `DB::TYPES` in `DB`. `Any` is a nillable version of the union of all types in `DB::TYPES`
alias Any = Nil | String | Int32 | Int64 | Float32 | Float64 | Slice(UInt8)
# :nodoc:
# Result of a `#exec` statement.
record ExecResult, rows_affected, last_insert_id
# :nodoc:
def self.driver_class(driver_name) # : Driver.class
@@drivers.not_nil![driver_name]
end

View file

@ -3,19 +3,22 @@ module DB
# All methods accepts a `query : String` and a set arguments.
#
# Three kind of statements can be performed:
# 1. `#exec` waits no response from the database.
# 2. `#scalar` reads a single value of the response. Use `#scalar?` if the response is nillable.
# 3. `#query` returns a ResultSet that allows iteration over the rows in the response and column information.
# 1. `#exec` waits no record response from the database. An `ExecResult` is returned.
# 2. `#scalar` reads a single value of the response. A `DB::Any` is returned.
# 3. `#query` returns a `ResultSet` that allows iteration over the rows in the response and column information.
#
# Arguments can be passed:
# * by position: `db.query("SELECT name FROM ... WHERE age > ?", age)`
# * by symbol: `db.query("SELECT name FROM ... WHERE age > :age", {age: age})`
# * by string: `db.query("SELECT name FROM ... WHERE age > :age", {"age": age})`
# Arguments can be passed by position
#
# ```
# db.query("SELECT name FROM ... WHERE age > ?", age)
# ```
#
# Convention of mapping how arguments are mapped to the query depends on each driver.
#
# Including `QueryMethods` requires a `prepare(query) : Statement` method.
module QueryMethods
abstract def prepare(query) : Statement
# Returns a `ResultSet` for the `query`.
# The `ResultSet` must be closed manually.
def query(query, *args)

View file

@ -47,11 +47,6 @@ module DB
protected def do_close
end
# Ensures it executes the query
def exec
move_next
end
# Move the next row in the result.
# Return `false` if no more rows are available.
# See `#each`

View file

@ -6,10 +6,9 @@ module DB
#
# 1. Subclass `Statements`
# 2. `Statements` are created from a custom driver `Connection#prepare` method.
# 3. `#begin_parameters` is called before the parameters are set.
# 4. `#add_parameter` methods helps to support 0-based positional arguments and named arguments
# 5. After parameters are set `#perform` is called to return a `ResultSet`
# 6. `#on_close` is called to release the statement resources.
# 3. `#perform_query` executes a query that is expected to return a `ResultSet`
# 4. `#perform_exec` executes a query that is expected to return an `ExecResult`
# 6. `#do_close` is called to release the statement resources.
abstract class Statement
getter connection
@ -17,11 +16,15 @@ module DB
@closed = false
end
# See `QueryMethods#exec`
def exec
perform_exec(Slice(Any).new(0)) # no overload matches ... with types Slice(NoReturn)
end
# See `QueryMethods#exec`
def exec(*args)
query(*args) do |rs|
rs.exec
end
# TODO better way to do it
perform_exec(args.to_a.to_unsafe.to_slice(args.size))
end
# See `QueryMethods#scalar`
@ -55,12 +58,12 @@ module DB
# See `QueryMethods#query`
def query(*args)
execute *args
perform_query *args
end
# See `QueryMethods#query`
def query(*args)
execute(*args).tap do |rs|
perform_query(*args).tap do |rs|
begin
yield rs
ensure
@ -69,13 +72,13 @@ module DB
end
end
private def execute : ResultSet
perform(Slice(Any).new(0))
private def perform_query : ResultSet
perform_query(Slice(Any).new(0)) # no overload matches ... with types Slice(NoReturn)
end
private def execute(*args) : ResultSet
private def perform_query(*args) : ResultSet
# TODO better way to do it
perform(args.to_a.to_unsafe.to_slice(args.size))
perform_query(args.to_a.to_unsafe.to_slice(args.size))
end
# Closes this statement.
@ -95,7 +98,8 @@ module DB
close
end
protected abstract def perform(args : Slice(Any)) : ResultSet
protected abstract def perform_query(args : Slice(Any)) : ResultSet
protected abstract def perform_exec(args : Slice(Any)) : ExecResult
protected def do_close
end