Add support for Count's on Joins

Author: mythz

src/ServiceStack.OrmLite/Expressions/SqlExpression.cs

@@ -518,7 +518,7 @@ public virtual string ToSelectStatement()
 
         public virtual string ToCountStatement()
         {
-            return DialectProvider.ToCountStatement(modelDef.ModelType, WhereExpression, null);
+            return "SELECT COUNT(*)" + BodyExpression;
         }
 
         public string SelectExpression

src/ServiceStack.OrmLite/IOrmLiteDialectProvider.cs

@@ -103,8 +103,6 @@ string ToSelectFromProcedureStatement(object fromObjWithProperties,
             string sqlFilter,
             params object[] filterParams);
 
-        string ToCountStatement(Type fromTableType, string sqlFilter, params object[] filterParams);
-
         string ToExecuteProcedureStatement(object objWithProperties);
 
         string ToCreateTableStatement(Type tableType);

src/ServiceStack.OrmLite/OrmLiteDialectProviderBase.cs

@@ -415,35 +415,6 @@ public virtual long InsertAndGetLastInsertId<T>(IDbCommand dbCmd)
             return dbCmd.ExecLongScalar();
         }
 
-        public virtual string ToCountStatement(Type fromTableType, string sqlFilter, params object[] filterParams)
-        {
-            var sql = new StringBuilder();
-            const string SelectStatement = "SELECT ";
-            var modelDef = fromTableType.GetModelDefinition();
-            var isFullSelectStatement =
-                !string.IsNullOrEmpty(sqlFilter)
-                && sqlFilter.TrimStart().StartsWith(SelectStatement, StringComparison.OrdinalIgnoreCase);
-
-            if (isFullSelectStatement) 
-                return (filterParams != null ? sqlFilter.SqlFmt(filterParams) : sqlFilter);
-
-            sql.AppendFormat("SELECT {0} FROM {1}", "COUNT(*)",
-                             GetQuotedTableName(modelDef));
-
-            if (!string.IsNullOrEmpty(sqlFilter))
-            {
-                sqlFilter = filterParams != null ? sqlFilter.SqlFmt(filterParams) : sqlFilter;
-                if ((!sqlFilter.StartsWith("ORDER ", StringComparison.OrdinalIgnoreCase)
-                    && !sqlFilter.StartsWith("LIMIT ", StringComparison.OrdinalIgnoreCase))
-                    && (!sqlFilter.StartsWith("WHERE ", StringComparison.OrdinalIgnoreCase)))
-                {
-                    sql.Append(" WHERE ");
-                }
-                sql.Append(" " + sqlFilter);
-            }
-            return sql.ToString();
-        }
-
         // Fmt
         public virtual string ToSelectStatement(Type tableType, string sqlFilter, params object[] filterParams)
         {

tests/ServiceStack.OrmLite.Tests/ApiSqlServerTests.cs

@@ -57,10 +57,10 @@ public void API_SqlServer_Examples()
             Assert.That(db.GetLastSql(), Is.EqualTo("SELECT Max(\"Age\") \nFROM \"Person\"\nWHERE (\"Age\" < 50)"));
 
             db.Count<Person>(x => x.Age < 50);
-            Assert.That(db.GetLastSql(), Is.EqualTo("SELECT COUNT(*) FROM \"Person\" WHERE (\"Age\" < 50)"));
+            Assert.That(db.GetLastSql(), Is.EqualTo("SELECT COUNT(*) \nFROM \"Person\"\nWHERE (\"Age\" < 50)"));
 
             db.Count(db.From<Person>().Where(x => x.Age < 50));
-            Assert.That(db.GetLastSql(), Is.EqualTo("SELECT COUNT(*) FROM \"Person\" WHERE (\"Age\" < 50)"));
+            Assert.That(db.GetLastSql(), Is.EqualTo("SELECT COUNT(*) \nFROM \"Person\"\nWHERE (\"Age\" < 50)"));
 
 
             db.Select<Person>("Age > 40");
@@ -186,10 +186,10 @@ public void API_SqlServer_Examples()
             Assert.That(db.GetLastSql(), Is.EqualTo("SELECT Id, LastName FROM Person WHERE Age < 50"));
 
             db.Exists<Person>(x => x.Age < 50);
-            Assert.That(db.GetLastSql(), Is.EqualTo("SELECT COUNT(*) FROM \"Person\" WHERE (\"Age\" < 50)"));
+            Assert.That(db.GetLastSql(), Is.EqualTo("SELECT COUNT(*) \nFROM \"Person\"\nWHERE (\"Age\" < 50)"));
 
             db.Exists(db.From<Person>().Where(x => x.Age < 50));
-            Assert.That(db.GetLastSql(), Is.EqualTo("SELECT COUNT(*) FROM \"Person\" WHERE (\"Age\" < 50)"));
+            Assert.That(db.GetLastSql(), Is.EqualTo("SELECT COUNT(*) \nFROM \"Person\"\nWHERE (\"Age\" < 50)"));
 
             db.Exists<Person>(new { Age = 42 });
             Assert.That(db.GetLastSql(), Is.EqualTo("SELECT \"Id\", \"FirstName\", \"LastName\", \"Age\" FROM \"Person\" WHERE \"Age\" = @Age"));

tests/ServiceStack.OrmLite.Tests/Expression/SqlExpressionTests.cs

@@ -221,17 +221,24 @@ public void Can_do_ToCountStatement_with_SqlExpression_if_where_expression_refer
                 db.DropAndCreateTable<LetterStat>();
 
                 var letterFrequency = new LetterFrequency { Letter = "A" };
-                letterFrequency.Id = (int)db.Insert<LetterFrequency>(letterFrequency, true);
+                letterFrequency.Id = (int)db.Insert(letterFrequency, true);
 
-                db.Insert<LetterStat>(new LetterStat { Letter = "A", LetterFrequencyId = letterFrequency.Id, Weighting = 1 });
+                db.Insert(new LetterStat { Letter = "A", LetterFrequencyId = letterFrequency.Id, Weighting = 1 });
 
                 var expr = db.From<LetterFrequency>()
                     .Join<LetterFrequency, LetterStat>()
                     .Where<LetterStat>(x => x.Id > 0);
 
-                var count = db.SqlScalar<int>(expr.ToCountStatement());
+                var count = db.SqlScalar<long>(expr.ToCountStatement());
 
                 Assert.That(count, Is.GreaterThan(0));
+
+                count = db.Count<LetterFrequency>(q => q.Join<LetterStat>().Where<LetterStat>(x => x.Id > 0));
+
+                Assert.That(count, Is.GreaterThan(0));
+
+                Assert.That(
+                    db.Exists<LetterFrequency>(q => q.Join<LetterStat>().Where<LetterStat>(x => x.Id > 0)));
             }
         }
     }