Inclusive/Exclusive Where Clauses and Intersect

Added two new features:  OrWhere extension for combining where clauses in an inclusive vs exclusive context (Or vs And) and Intersect extension.

Dapper.SqlBuilder/SqlBuilder.cs

@@ -14,6 +14,7 @@ class Clause
         {
             public string Sql { get; set; }
             public object Parameters { get; set; }
+            public bool IsInclusive { get; set; }
         }
 
         class Clauses : List<Clause>
@@ -35,7 +36,18 @@ public string ResolveClauses(DynamicParameters p)
                 {
                     p.AddDynamicParams(item.Parameters);
                 }
-                return prefix + string.Join(joiner, this.Select(c => c.Sql)) + postfix;
+                return this.Any(a => a.IsInclusive)
+                    ? prefix +
+                      string.Join(joiner,
+                          this.Where(a => !a.IsInclusive)
+                              .Select(c => c.Sql)
+                              .Union(new[]
+                              {
+                                  " ( " +
+                                  string.Join(" OR ", this.Where(a => a.IsInclusive).Select(c => c.Sql).ToArray()) +
+                                  " ) "
+                              })) + postfix
+                    : prefix + string.Join(joiner, this.Select(c => c.Sql)) + postfix;
             }
         }
 
@@ -94,7 +106,7 @@ public Template AddTemplate(string sql, dynamic parameters = null)
             return new Template(this, sql, parameters);
         }
 
-        void AddClause(string name, string sql, object parameters, string joiner, string prefix = "", string postfix = "")
+        void AddClause(string name, string sql, object parameters, string joiner, string prefix = "", string postfix = "", bool IsInclusive = false)
         {
             Clauses clauses;
             if (!data.TryGetValue(name, out clauses))
@@ -106,6 +118,12 @@ void AddClause(string name, string sql, object parameters, string joiner, string
             seq++;
         }
 
+        public SqlBuilder Intersect(string sql, dynamic parameters = null)
+        {
+            AddClause("intersect", sql, parameters, joiner: "\nINTERSECT\n ", prefix: "\n ", postfix: "\n");
+            return this;
+        }
+        
         public SqlBuilder InnerJoin(string sql, dynamic parameters = null)
         {
             AddClause("innerjoin", sql, parameters, joiner: "\nINNER JOIN ", prefix: "\nINNER JOIN ", postfix: "\n");
@@ -130,6 +148,12 @@ public SqlBuilder Where(string sql, dynamic parameters = null)
             return this;
         }
 
+        public SqlBuilder OrWhere(string sql, dynamic parameters = null)
+        {
+            AddClause("where", sql, parameters, " AND ", prefix: "WHERE ", postfix: "\n", IsInclusive: true);
+            return this;
+        }
+        
         public SqlBuilder OrderBy(string sql, dynamic parameters = null)
         {
             AddClause("orderby", sql, parameters, " , ", prefix: "ORDER BY ", postfix: "\n");