[improvment] 反向工程中，On级别支持扩大字符串长度，这是常用操作，并且不会丢失数据

NewLifeX · Nov 1, 2023 · c6bdaf2 · c6bdaf2
1 parent 6792371
commit c6bdaf2
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Showing 3 changed files with 23 additions and 7 deletions.
diff --git a/XCode/DataAccessLayer/MetaData/DbMetaData.cs b/XCode/DataAccessLayer/MetaData/DbMetaData.cs
@@ -208,18 +208,22 @@ protected static DbTable Select(DbTable ds, String name, Object value)
 
     static StringBuilder Append(StringBuilder sb, String separator, String value)
     {
+        if (value.IsNullOrEmpty()) return sb;
+
         if (sb.Length > 0) sb.Append(separator);
 
-        if (value != null) sb.Append(value);
+        sb.Append(value);
 
         return sb;
     }
 
     static StringBuilder Append(StringBuilder sb, Char separator, String value)
     {
+        if (value.IsNullOrEmpty()) return sb;
+
         if (sb.Length > 0) sb.Append(separator);
 
-        if (value != null) sb.Append(value);
+        sb.Append(value);
 
         return sb;
     }

diff --git a/XCode/DataAccessLayer/MetaData/DbMetaData_Negative.cs b/XCode/DataAccessLayer/MetaData/DbMetaData_Negative.cs
@@ -273,7 +273,7 @@ protected virtual String CheckColumnsChange(IDataTable entitytable, IDataTable d
                 PerformSchema(sb, @readonly || onlyCreate, DDLSchema.AlterColumn, item, dbf);
             }
             else if (IsColumnLengthChanged(item, dbf, entityDb))
-                PerformSchema(sb, @readonly || onlyCreate, DDLSchema.AlterColumn, item, dbf);
+                PerformSchema(sb, @readonly, DDLSchema.AlterColumn, item, dbf);
             else if (IsColumnChanged(item, dbf, entityDb))
                 PerformSchema(sb, @readonly || onlyCreate, DDLSchema.AlterColumn, item, dbf);
 
@@ -441,10 +441,22 @@ protected virtual Boolean IsColumnChanged(IDataColumn entityColumn, IDataColumn
         // 是否已改变
         var isChanged = false;
 
+        // 仅针对字符串类型比较长度
+        if (!isChanged && entityColumn.DataType == typeof(String) && entityColumn.Length != dbColumn.Length)
+        {
+            isChanged = true;
+
+            // 如果是大文本类型，长度可能不等
+            if ((entityColumn.Length > Database.LongTextLength || entityColumn.Length <= 0)
+                && (entityDb != null && dbColumn.Length > entityDb.LongTextLength || dbColumn.Length <= 0)
+                || dbColumn.RawType.EqualIgnoreCase("ntext", "text", "sysname"))
+                isChanged = false;
+        }
+
         return isChanged;
     }
 
-    /// <summary>检查字段是否有改变，除了默认值和备注以外</summary>
+    /// <summary>检查字段长度是否扩大</summary>
     /// <param name="entityColumn"></param>
     /// <param name="dbColumn"></param>
     /// <param name="entityDb"></param>
@@ -455,7 +467,7 @@ protected virtual Boolean IsColumnLengthChanged(IDataColumn entityColumn, IDataC
         var isChanged = false;
 
         // 仅针对字符串类型比较长度
-        if (!isChanged && entityColumn.DataType == typeof(String) && entityColumn.Length != dbColumn.Length)
+        if (!isChanged && entityColumn.DataType == typeof(String) && entityColumn.Length > dbColumn.Length)
         {
             isChanged = true;
 

diff --git a/XCode/DataAccessLayer/MetaData/DbMetaData_Positive.cs b/XCode/DataAccessLayer/MetaData/DbMetaData_Positive.cs
@@ -330,9 +330,9 @@ protected virtual void FixIndex(IDataIndex index, DataRow dr) { }
 
     #region 数据类型
     /// <summary>类型映射</summary>
-    protected IDictionary<Type, String[]> Types { get; set; }
+    protected IDictionary<Type, String[]> Types { get; set; } = null!;
 
-    protected List<KeyValuePair<Type, Type>> _FieldTypeMaps;
+    protected List<KeyValuePair<Type, Type>>? _FieldTypeMaps;
     /// <summary>字段类型映射</summary>
     protected virtual List<KeyValuePair<Type, Type>> FieldTypeMaps
     {