Normalize best-effort vs strict operator usage

README.md

@@ -213,6 +213,60 @@ Rebel::SQL() { select count(:id).as(:count), from: :customers, where: { :age =>
 # While we're counting things, let's group results
 Rebel::SQL() { select count(:id).as(:count), :country, from: :customers, group: by(:country).having(count(:customer_id) => 5) }
 #=> SELECT COUNT("id") AS "count", "country" FROM "customers" GROUP BY "country" HAVING COUNT("customer_id") = 5
+
+# Passing a hash does a best effort to map Ruby to SQL
+Rebel::SQL() { select :id, from: :customers, where: { :age => 42 } }
+#=> SELECT "id" FROM "customers" WHERE "age" = 42
+Rebel::SQL() { select :id, from: :customers, where: { :age => [20, 21, 22] } }
+#=> SELECT "id" FROM "customers" WHERE "age" IN (20, 21, 22)
+Rebel::SQL() { select :id, from: :customers, where: { :age => nil } }
+#=> SELECT "id" FROM "customers" WHERE "age" IS NULL
+
+# Using operators ensures the expected SQL operator is used
+Rebel::SQL() { select :id, from: :customers, where: name(:age).eq(42) }
+#=> SELECT "id" FROM "customers" WHERE "age" = 42
+Rebel::SQL() { select :id, from: :customers, where: name(:age).eq(nil) }
+#=> SELECT "id" FROM "customers" WHERE "age" = NULL
+Rebel::SQL() { select :id, from: :customers, where: name(:age).ne(42) }
+#=> SELECT "id" FROM "customers" WHERE "age" != NULL
+Rebel::SQL() { select :id, from: :customers, where: name(:age).is(42) }
+#=> SELECT "id" FROM "customers" WHERE "age" IS 42
+Rebel::SQL() { select :id, from: :customers, where: name(:age).is(nil) }
+#=> SELECT "id" FROM "customers" WHERE "age" IS NULL
+Rebel::SQL() { select :id, from: :customers, where: name(:age).is_not(nil) }
+#=> SELECT "id" FROM "customers" WHERE "age" IS NOT NULL
+
+# Other operators are available
+Rebel::SQL() { select :id, from: :customers, where: name(:age).ge(42) }
+#=> SELECT "id" FROM "customers" WHERE "age" >= 42
+Rebel::SQL() { select :id, from: :customers, where: name(:age).in(21, 22, 23) }
+#=> SELECT "id" FROM "customers" WHERE "age" IN (21, 22, 23)
+Rebel::SQL() { select :id, from: :customers, where: name(:first_name).like("J%") }
+#=> SELECT "id" FROM "customers" WHERE "first_name" LIKE "J%"
+
+# Aliases to overload operators are available
+Rebel::SQL() { select :id, from: :customers, where: name(:age) == 42 }
+#=> SELECT "id" FROM "customers" WHERE "age" = 42
+Rebel::SQL() { select :id, from: :customers, where: name(:age) < 42 }
+#=> SELECT "id" FROM "customers" WHERE "age" < 42
+Rebel::SQL() { select :id, from: :customers, where: name(:age) >= 42 }
+#=> SELECT "id" FROM "customers" WHERE "age" >= 42
+Rebel::SQL() { select :id, from: :customers, where: name(:age) != 42 }
+#=> SELECT "id" FROM "customers" WHERE "age" != 42
+
+# Conditions can be combined
+Rebel::SQL() { select :id, from: :customers, where: name(:age).gt(42).or(name(:age).lt(21)) }
+#=> SELECT "id" FROM "customers" WHERE ("age" > 42 OR "age" < 21)
+Rebel::SQL() { select :id, from: :customers, where: (name(:age) < 42).and(name(:age) > 21) }
+#=> SELECT "id" FROM "customers" WHERE ("age" < 42 AND "age" > 21)
+
+# Binary-wise operators can be used to tie conditions
+# WARNING: Usefulness if this hack is still debated. It might be removed in the future.
+Rebel::SQL() { select :id, from: :customers, where: ((name(:age) > 42) | (name(:age) < 21)) }
+#=> SELECT "id" FROM "customers" WHERE ("age" > 42 OR "age" < 21)
+Rebel::SQL() { select :id, from: :customers, where: name(:age).lt(42) & (name(:age).gt(21)) }
+#=> SELECT "id" FROM "customers" WHERE ("age" < 42 AND "age" > 21)
+
 ```
 
 ### Query execution

lib/rebel/sql.rb

@@ -117,26 +117,22 @@ module Rebel
     alias | or
 
     def eq(n)
-      case n
+      sql.raw("#{self} = #{sql.name_or_value(n)}")
-      when nil
-        sql.raw("#{self} IS NULL")
-      else
-        sql.raw("#{self} = #{sql.name_or_value(n)}")
-      end
     end
     alias == eq
-    alias is eq
+
+    def is(n)
+      sql.raw("#{self} IS #{sql.name_or_value(n)}")
+    end
 
     def ne(n)
-      case n
+      sql.raw("#{self} != #{sql.name_or_value(n)}")
-      when nil
-        sql.raw("#{self} IS NOT NULL")
-      else
-        sql.raw("#{self} != #{sql.name_or_value(n)}")
-      end
     end
     alias != ne
-    alias is_not ne
+
+    def is_not(n)
+      sql.raw("#{self} IS NOT #{sql.name_or_value(n)}")
+    end
 
     def lt(n)
       sql.raw("#{self} < #{sql.name_or_value(n)}")
@@ -343,6 +339,8 @@ module Rebel
       case right
       when Array
         name(left).in(*right)
+      when nil
+        name(left).is(name_or_value(right))
       else
         name(left).eq(name_or_value(right))
       end

test/test_raw.rb

@@ -48,19 +48,19 @@ class TestRaw < Minitest::Test
 
   def test_is
     assert_sql('"foo" IS NULL') { name(:foo).is(nil) }
-    assert_sql('"foo" = 42') { name(:foo).is(42) }
+    assert_sql('"foo" IS 42') { name(:foo).is(42) }
-    assert_sql('"foo" = "bar"') { name(:foo).is(name(:bar)) }
+    assert_sql('"foo" IS "bar"') { name(:foo).is(name(:bar)) }
   end
 
   def test_is_not
     assert_sql('"foo" IS NOT NULL') { name(:foo).is_not(nil) }
-    assert_sql('"foo" != 42') { name(:foo).is_not(42) }
+    assert_sql('"foo" IS NOT 42') { name(:foo).is_not(42) }
-    assert_sql('"foo" != "bar"') { name(:foo).is_not(name(:bar)) }
+    assert_sql('"foo" IS NOT "bar"') { name(:foo).is_not(name(:bar)) }
   end
 
   def test_eq
-    assert_sql('"foo" IS NULL') { name(:foo).eq(nil) }
+    assert_sql('"foo" = NULL') { name(:foo).eq(nil) }
-    assert_sql('"foo" IS NULL') { name(:foo) == nil }
+    assert_sql('"foo" = NULL') { name(:foo) == nil }
     assert_sql('"foo" = "bar"') { name(:foo).eq(name(:bar)) }
     assert_sql('"foo" = "bar"') { name(:foo) == name(:bar) }
   end
@@ -68,8 +68,8 @@ class TestRaw < Minitest::Test
   def test_ne
     assert_sql('"foo" != "bar"') { name(:foo).ne(name(:bar)) }
     assert_sql('"foo" != "bar"') { name(:foo) != name(:bar) }
-    assert_sql('"foo" IS NOT NULL') { name(:foo).ne(nil) }
+    assert_sql('"foo" != NULL') { name(:foo).ne(nil) }
-    assert_sql('"foo" IS NOT NULL') { name(:foo) != nil }
+    assert_sql('"foo" != NULL') { name(:foo) != nil }
   end
 
   def test_lt
@@ -112,6 +112,8 @@ class TestRaw < Minitest::Test
     assert_sql('WHERE "foo" = 1 AND "bar" = 2 AND "baz" = 3') { where?(foo: 1, bar: 2, baz: 3) }
     assert_sql('WHERE ("foo" = 1 OR "bar" = 2) AND "baz" = 3') { where?(name(:foo).eq(1).or(name(:bar).eq(2)), name(:baz).eq(3)) }
     assert_sql('WHERE ("foo" = 1 OR "bar" = 2)') { where?(name(:foo).eq(1).or(name(:bar).eq(2))) }
+    assert_sql('WHERE "foo" IS NULL') { where?(foo: nil) }
+    assert_sql('WHERE "foo" IN (1, 2, 3)') { where?(foo: [1, 2, 3]) }
   end
 
   def test_join