diff --git a/spec/std/db/dummy_driver.cr b/spec/std/db/dummy_driver.cr
index 13cbbe6..9b9b5d9 100644
--- a/spec/std/db/dummy_driver.cr
+++ b/spec/std/db/dummy_driver.cr
@@ -4,16 +4,22 @@ class DummyDriver < DB::Driver
   end
 
   class DummyStatement < DB::Statement
+    property! params
+
     def initialize(driver, @items)
       super(driver)
     end
 
     protected def add_parameter(index : Int32, value)
-      raise "not implemented"
+      params[index] = value
     end
 
     protected def add_parameter(name : String, value)
-      raise "not implemented"
+      params[":#{name}"] = value
+    end
+
+    protected def before_execute
+      @params = Hash(Int32 | String, DB::Any).new
     end
 
     protected def execute
@@ -34,11 +40,24 @@ class DummyDriver < DB::Driver
       end
     end
 
-    def read?(t : String.class)
+    private def read? : DB::Any?
       n = @values.not_nil!.next
       raise "end of row" if n.is_a?(Iterator::Stop)
       return nil if n == "NULL"
-      return n as String
+
+      if n == "?"
+        return @statement.params[1]
+      end
+
+      if n.starts_with?(":")
+        return @statement.params[n]
+      end
+
+      return n
+    end
+
+    def read?(t : String.class)
+      read?.try &.to_s
     end
 
     def read?(t : Int32.class)
@@ -50,12 +69,24 @@ class DummyDriver < DB::Driver
     end
 
     def read?(t : Float32.class)
-      read?(String).try &.to_f23
+      read?(String).try &.to_f32
     end
 
     def read?(t : Float64.class)
       read?(String).try &.to_f64
     end
+
+    def read?(t : Slice(UInt8).class)
+      value = read?
+      if value.is_a?(Nil)
+        value
+      elsif value.is_a?(String)
+        ary = value.bytes
+        Slice.new(ary.to_unsafe, ary.size)
+      else
+        value as Slice(UInt8)
+      end
+    end
   end
 end
 
diff --git a/spec/std/db/dummy_driver_spec.cr b/spec/std/db/dummy_driver_spec.cr
index f910301..6ba3994 100644
--- a/spec/std/db/dummy_driver_spec.cr
+++ b/spec/std/db/dummy_driver_spec.cr
@@ -65,6 +65,15 @@ describe DummyDriver do
       result_set.read(Int64).should eq(2i64)
     end
 
+    it "should enumerate blob fields" do
+      result_set = get_dummy.prepare("az,AZ").exec
+      result_set.move_next
+      ary = [97u8, 122u8]
+      result_set.read(Slice(UInt8)).should eq(Slice.new(ary.to_unsafe, ary.size))
+      ary = [65u8, 90u8]
+      result_set.read(Slice(UInt8)).should eq(Slice.new(ary.to_unsafe, ary.size))
+    end
+
     it "should enumerate records using each" do
       nums = [] of Int32
       result_set = get_dummy.prepare("3,4 1,2").exec
@@ -75,5 +84,37 @@ describe DummyDriver do
 
       nums.should eq([3, 4, 1, 2])
     end
+
+    {% for value in [1, 1_i64, "hello", 1.5, 1.5_f32] %}
+      it "should set arguments for {{value.id}}" do
+        result_set = get_dummy.exec "?", {{value}}
+        result_set.move_next.should be_true
+        result_set.read(typeof({{value}})).should eq({{value}})
+      end
+
+      it "should set arguments by symbol for {{value.id}}" do
+        result_set = get_dummy.exec ":once :twice", {once: {{value}}, twice: {{value + value}} }
+        result_set.move_next.should be_true
+        result_set.read(typeof({{value}})).should eq({{value}})
+        result_set.move_next.should be_true
+        result_set.read(typeof({{value}})).should eq({{value + value}})
+      end
+
+      it "should set arguments by string for {{value.id}}" do
+        result_set = get_dummy.exec ":once :twice", {"once": {{value}}, "twice": {{value + value}} }
+        result_set.move_next.should be_true
+        result_set.read(typeof({{value}})).should eq({{value}})
+        result_set.move_next.should be_true
+        result_set.read(typeof({{value}})).should eq({{value + value}})
+      end
+    {% end %}
+
+    it "executes and selects blob" do
+      ary = UInt8[0x53, 0x51, 0x4C]
+      slice = Slice.new(ary.to_unsafe, ary.size)
+      result_set = get_dummy.exec "?", slice
+      result_set.move_next
+      result_set.read(Slice(UInt8)).to_a.should eq(ary)
+    end
   end
 end
diff --git a/src/db/db.cr b/src/db/db.cr
index 77cea9d..52b0f9a 100644
--- a/src/db/db.cr
+++ b/src/db/db.cr
@@ -1,5 +1,6 @@
 module DB
-  TYPES = [String, Int32, Int64, Float32, Float64]
+  TYPES = [String, Int32, Int64, Float32, Float64, Slice(UInt8)]
+  alias Any = String | Int32 | Int64 | Float32 | Float64 | Slice(UInt8)
 
   def self.driver_class(name) # : Driver.class
     @@drivers.not_nil![name]
diff --git a/src/db/statement.cr b/src/db/statement.cr
index c9c4e40..30f2440 100644
--- a/src/db/statement.cr
+++ b/src/db/statement.cr
@@ -9,6 +9,12 @@ module DB
       exec args
     end
 
+    def exec(arg : Slice(UInt8))
+      before_execute
+      add_parameter 1, arg
+      execute
+    end
+
     def exec(args : Enumerable)
       before_execute
       args.each_with_index(1) do |arg, index|