add blob support

spec/driver_spec.cr

@@ -89,6 +89,23 @@ describe Driver do
     end
   {% end %}
 
+  it "executes and selects blob" do
+    with_db do |db|
+      result_set = db.exec %(select X'53514C697465')
+      result_set.move_next
+      result_set.read(Slice(UInt8)).to_a.should eq([0x53, 0x51, 0x4C, 0x69, 0x74, 0x65])
+    end
+  end
+
+  it "executes with bind blob" do
+    with_db do |db|
+      ary = UInt8[0x53, 0x51, 0x4C, 0x69, 0x74, 0x65]
+      result_set = db.exec %(select cast(? as BLOB)), Slice.new(ary.to_unsafe, ary.size)
+      result_set.move_next
+      result_set.read(Slice(UInt8)).to_a.should eq(ary)
+    end
+  end
+
   it "executes with named bind using symbol" do
     with_db do |db|
       result_set = db.exec(%(select :value), {value: "hello"})

src/sqlite3/result_set2.cr

@@ -44,7 +44,17 @@ class SQLite3::ResultSet2 < DB::ResultSet
   end
 
   def read(t : Float64.class) : Float64
-    moving_column { LibSQLite3.column_double(self, @column_index) }
+    moving_column { |col| LibSQLite3.column_double(self, col) }
+  end
+
+  def read(t : Slice(UInt8).class) : Slice(UInt8)
+    moving_column do |col|
+      blob = LibSQLite3.column_blob(self, col)
+      bytes = LibSQLite3.column_bytes(self, col)
+      ptr = Pointer(UInt8).malloc(bytes)
+      ptr.copy_from(blob, bytes)
+      Slice(UInt8).new(ptr, bytes)
+    end
   end
 
   def to_unsafe
@@ -52,7 +62,11 @@ class SQLite3::ResultSet2 < DB::ResultSet
   end
 
   private def read_nil?
-    LibSQLite3.column_type(self, @column_index) == Type::NULL
+    column_sqlite_type == Type::NULL
+  end
+
+  private def column_sqlite_type
+    LibSQLite3.column_type(self, @column_index)
   end
 
   # :nodoc:

src/sqlite3/statement2.cr

@@ -47,6 +47,10 @@ class SQLite3::Statement2 < DB::Statement
     check LibSQLite3.bind_text(self, index, value, value.bytesize, nil)
   end
 
+  private def bind_arg(index, value : Slice(UInt8))
+    check LibSQLite3.bind_blob(self, index, value, value.size, nil)
+  end
+
   private def check(code)
     raise Exception.new(@driver) unless code == 0
   end