diff --git a/Src/Asp.NetCore2/SqlSeverTest/SqlSugar/Abstract/CodeFirstProvider/CodeFirstProvider.cs b/Src/Asp.NetCore2/SqlSeverTest/SqlSugar/Abstract/CodeFirstProvider/CodeFirstProvider.cs
index 9e0728e8e..bbdeba555 100644
--- a/Src/Asp.NetCore2/SqlSeverTest/SqlSugar/Abstract/CodeFirstProvider/CodeFirstProvider.cs
+++ b/Src/Asp.NetCore2/SqlSeverTest/SqlSugar/Abstract/CodeFirstProvider/CodeFirstProvider.cs
@@ -226,6 +226,16 @@ namespace SqlSugar
                 }
                 foreach (var item in alterColumns)
                 {
+
+                    if (this.Context.CurrentConnectionConfig.DbType == DbType.Oracle) 
+                    {
+                        var entityColumnItem = entityColumns.FirstOrDefault(y => y.DbColumnName == item.DbColumnName);
+                        if (entityColumnItem!=null&&!string.IsNullOrEmpty(entityColumnItem.DataType)) 
+                        {
+                            continue;
+                        }
+                    }
+
                     this.Context.DbMaintenance.UpdateColumn(tableName, EntityColumnToDbColumn(entityInfo, tableName, item));
                     isChange = true;
                 }
diff --git a/Src/Asp.NetCore2/SqlSeverTest/SqlSugar/Realization/Oracle/OracleProvider.cs b/Src/Asp.NetCore2/SqlSeverTest/SqlSugar/Realization/Oracle/OracleProvider.cs
index 0b003a727..7c42affff 100644
--- a/Src/Asp.NetCore2/SqlSeverTest/SqlSugar/Realization/Oracle/OracleProvider.cs
+++ b/Src/Asp.NetCore2/SqlSeverTest/SqlSugar/Realization/Oracle/OracleProvider.cs
@@ -137,6 +137,7 @@ namespace SqlSugar
                 if (parameter.IsClob)
                 {
                     sqlParameter.OracleDbType = OracleDbType.Clob;
+                    sqlParameter.Value = sqlParameter.Value;
                 }
                 if (sqlParameter.DbType == System.Data.DbType.Guid)
                 {
@@ -165,6 +166,11 @@ namespace SqlSugar
                     sqlParameter.Value = parameter.Value;
                     sqlParameter.DbType = System.Data.DbType.Date;
                 }
+                else if (parameter.DbType == System.Data.DbType.AnsiStringFixedLength)
+                {
+                    sqlParameter.DbType = System.Data.DbType.AnsiStringFixedLength;
+                    sqlParameter.Value = parameter.Value;
+                }
                 else
                 {
                     if (parameter.Value != null && parameter.Value.GetType() == UtilConstants.GuidType)