introduce unprepared statements

* rename QueryMethods#prepare to QueryMethods#build
* rename Connection#build_statement to Connection#build_prepared_statement
* add Connection#build_unprepared_statement
* add Connection #prepared and #unprepared dsl methods

spec/statement_spec.cr

@@ -1,15 +1,25 @@
 require "./spec_helper"
 
 describe DB::Statement do
-  it "should prepare statements" do
+  it "should build prepared statements" do
     with_dummy_connection do |cnn|
-      cnn.prepare("the query").should be_a(DB::Statement)
+      prepared = cnn.prepared("the query")
+      prepared.should be_a(DB::Statement)
+      prepared.as(DummyDriver::DummyStatement).prepared?.should be_true
+    end
+  end
+
+  it "should build unprepared statements" do
+    with_dummy_connection do |cnn|
+      prepared = cnn.unprepared("the query")
+      prepared.should be_a(DB::Statement)
+      prepared.as(DummyDriver::DummyStatement).prepared?.should be_false
     end
   end
 
   it "should initialize positional params in query" do
     with_dummy_connection do |cnn|
-      stmt = cnn.prepare("the query").as(DummyDriver::DummyStatement)
+      stmt = cnn.prepared("the query").as(DummyDriver::DummyStatement)
       stmt.query "a", 1, nil
       stmt.params[0].should eq("a")
       stmt.params[1].should eq(1)
@@ -19,7 +29,7 @@ describe DB::Statement do
 
   it "should initialize positional params in query with array" do
     with_dummy_connection do |cnn|
-      stmt = cnn.prepare("the query").as(DummyDriver::DummyStatement)
+      stmt = cnn.prepared("the query").as(DummyDriver::DummyStatement)
       stmt.query ["a", 1, nil]
       stmt.params[0].should eq("a")
       stmt.params[1].should eq(1)
@@ -29,7 +39,7 @@ describe DB::Statement do
 
   it "should initialize positional params in exec" do
     with_dummy_connection do |cnn|
-      stmt = cnn.prepare("the query").as(DummyDriver::DummyStatement)
+      stmt = cnn.prepared("the query").as(DummyDriver::DummyStatement)
       stmt.exec "a", 1, nil
       stmt.params[0].should eq("a")
       stmt.params[1].should eq(1)
@@ -39,7 +49,7 @@ describe DB::Statement do
 
   it "should initialize positional params in exec with array" do
     with_dummy_connection do |cnn|
-      stmt = cnn.prepare("the query").as(DummyDriver::DummyStatement)
+      stmt = cnn.prepared("the query").as(DummyDriver::DummyStatement)
       stmt.exec ["a", 1, nil]
       stmt.params[0].should eq("a")
       stmt.params[1].should eq(1)
@@ -49,7 +59,7 @@ describe DB::Statement do
 
   it "should initialize positional params in scalar" do
     with_dummy_connection do |cnn|
-      stmt = cnn.prepare("the query").as(DummyDriver::DummyStatement)
+      stmt = cnn.prepared("the query").as(DummyDriver::DummyStatement)
       stmt.scalar "a", 1, nil
       stmt.params[0].should eq("a")
       stmt.params[1].should eq(1)
@@ -59,7 +69,7 @@ describe DB::Statement do
 
   it "query with block should not close statement" do
     with_dummy_connection do |cnn|
-      stmt = cnn.prepare "3,4 1,2"
+      stmt = cnn.prepared "3,4 1,2"
       stmt.query
       stmt.closed?.should be_false
     end
@@ -68,7 +78,7 @@ describe DB::Statement do
   it "closing connection should close statement" do
     stmt = uninitialized DB::Statement
     with_dummy_connection do |cnn|
-      stmt = cnn.prepare "3,4 1,2"
+      stmt = cnn.prepared "3,4 1,2"
       stmt.query
     end
     stmt.closed?.should be_true
@@ -76,7 +86,7 @@ describe DB::Statement do
 
   it "query with block should not close statement" do
     with_dummy_connection do |cnn|
-      stmt = cnn.prepare "3,4 1,2"
+      stmt = cnn.prepared "3,4 1,2"
       stmt.query do |rs|
       end
       stmt.closed?.should be_false
@@ -85,7 +95,7 @@ describe DB::Statement do
 
   it "query should not close statement" do
     with_dummy_connection do |cnn|
-      stmt = cnn.prepare "3,4 1,2"
+      stmt = cnn.prepared "3,4 1,2"
       stmt.query do |rs|
       end
       stmt.closed?.should be_false
@@ -94,7 +104,7 @@ describe DB::Statement do
 
   it "scalar should not close statement" do
     with_dummy_connection do |cnn|
-      stmt = cnn.prepare "3,4 1,2"
+      stmt = cnn.prepared "3,4 1,2"
       stmt.scalar
       stmt.closed?.should be_false
     end
@@ -102,7 +112,7 @@ describe DB::Statement do
 
   it "exec should not close statement" do
     with_dummy_connection do |cnn|
-      stmt = cnn.prepare "3,4 1,2"
+      stmt = cnn.prepared "3,4 1,2"
       stmt.exec
       stmt.closed?.should be_false
     end
@@ -110,11 +120,11 @@ describe DB::Statement do
 
   it "connection should cache statements by query" do
     with_dummy_connection do |cnn|
-      rs = cnn.query "1, ?", 2
+      rs = cnn.prepared.query "1, ?", 2
       stmt = rs.statement
       rs.close
 
-      rs = cnn.query "1, ?", 4
+      rs = cnn.prepared.query "1, ?", 4
       rs.statement.should be(stmt)
     end
   end