Add user case test

Src/Asp.NetCore2/SqlSeverTest/UserTestCases/UnitTest/UinitCustomConvert.cs

@@ -50,6 +50,44 @@ namespace OrmTest
             {
                 throw new Exception("unit error");
             }
+            var datas=db.Queryable<Uinitadfa22122X>() 
+                .Where(it => it.EnumValue.Contains("a"))
+                .ToSql();
+            if (datas.Value.FirstOrDefault().DbType != System.Data.DbType.AnsiString) 
+            {
+                throw new Exception("unit error");
+            }
+        }
+    }
+    public class Uinitadfa22122X
+    {
+
+        
+        [SqlSugar.SugarColumn(ColumnDataType = "varchar(20)", SqlParameterDbType = typeof(Uinitadfa22122XConvert), IsNullable = true)]
+        public string EnumValue { get; set; }
+    }
+    public class Uinitadfa22122XConvert : ISugarDataConverter
+    {
+        public SugarParameter ParameterConverter<T>(object columnValue, int columnIndex)
+        {
+            var name = "@MyEnmu" + columnIndex;
+            Type undertype = SqlSugar.UtilMethods.GetUnderType(typeof(T));//获取没有nullable的枚举类型
+            if (columnValue == null)
+            {
+                return new SugarParameter(name, null);
+            }
+            else
+            { 
+                return new SugarParameter(name, columnValue) {  DbType=System.Data.DbType.AnsiString };
+            }
+        }
+
+        public T QueryConverter<T>(IDataRecord dr, int i)
+        {
+
+            var str = dr.GetString(i);
+            Type undertype = SqlSugar.UtilMethods.GetUnderType(typeof(T));//获取没有nullable的枚举类型
+            return (T)Enum.Parse(undertype, str);
         }
     }
     public class Uinitadfa22122