处理 XSD 数据集 ConstraintException
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09-06-2019 - |
题
有人对处理 XSD 数据集引发的 ConstraintException 有任何建议吗?
这是神秘消息的例外情况:
System.Data.ConstraintException : Failed to enable constraints. One or more rows contain values violating non-null, unique, or foreign-key constraints.
解决方案
我最近发现的一些技巧。
最好使用 TableAdapter FillByDataXXXX() 方法而不是 GetDataByXXXX() 方法,因为可以询问传递到 fill 方法中的 DataTable 以获取线索:
- datatable.getErrors()返回错误的dataRow Instances错误
- datarow.rowerror包含一个行错误的描述
- datarow.getColumnsinerror()错误返回一系列数据列实例
最近,我将一些询问代码包装到 ConstraintException 的子类中,事实证明这是一个有用的调试起点。
C# 用法示例:
Example.DataSet.fooDataTable table = new DataSet.fooDataTable();
try
{
tableAdapter.Fill(table);
}
catch (ConstraintException ex)
{
// pass the DataTable to DetailedConstraintException to get a more detailed Message property
throw new DetailedConstraintException("error filling table", table, ex);
}
输出:
详细约束异常:表格填充失败
报告 ConstraintExceptionHelper.DataSet+fooDataTable [foo] 的错误
错误列:[1]
[PRODUCT_ID] - 受影响的总行数:1085
行错误:[4]
[列“Product_ID”必须是唯一的。值“1”已存在。] - 受影响的总行数:1009
[列“Product_ID”必须是唯一的。值“2”已存在。] - 受影响的总行数:20
[列“Product_ID”必须是唯一的。值“4”已存在。] - 受影响的总行数:34
[列“Product_ID”必须是唯一的。值“6”已存在。] - 受影响的总行数:22
----> System.Data.ConstraintException :无法启用约束。一行或多行包含违反非空、唯一或外键约束的值。
我不知道在 Stack Overflow 答案中包含的代码是否过多,但这里是完整的 C# 类。免责声明:这对我有用,请随意使用/适当修改。
using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
namespace ConstraintExceptionHelper
{
/// <summary>
/// Subclass of ConstraintException that explains row and column errors in the Message property
/// </summary>
public class DetailedConstraintException : ConstraintException
{
private const int InitialCountValue = 1;
/// <summary>
/// Initialises a new instance of DetailedConstraintException with the specified string and DataTable
/// </summary>
/// <param name="message">exception message</param>
/// <param name="ErroredTable">DataTable in error</param>
public DetailedConstraintException(string message, DataTable erroredTable)
: base(message)
{
ErroredTable = erroredTable;
}
/// <summary>
/// Initialises a new instance of DetailedConstraintException with the specified string, DataTable and inner Exception
/// </summary>
/// <param name="message">exception message</param>
/// <param name="ErroredTable">DataTable in error</param>
/// <param name="inner">the original exception</param>
public DetailedConstraintException(string message, DataTable erroredTable, Exception inner)
: base(message, inner)
{
ErroredTable = erroredTable;
}
private string buildErrorSummaryMessage()
{
if (null == ErroredTable) { return "No errored DataTable specified"; }
if (!ErroredTable.HasErrors) { return "No Row Errors reported in DataTable=[" + ErroredTable.TableName + "]"; }
foreach (DataRow row in ErroredTable.GetErrors())
{
recordColumnsInError(row);
recordRowsInError(row);
}
StringBuilder sb = new StringBuilder();
appendSummaryIntro(sb);
appendErroredColumns(sb);
appendRowErrors(sb);
return sb.ToString();
}
private void recordColumnsInError(DataRow row)
{
foreach (DataColumn column in row.GetColumnsInError())
{
if (_erroredColumns.ContainsKey(column.ColumnName))
{
_erroredColumns[column.ColumnName]++;
continue;
}
_erroredColumns.Add(column.ColumnName, InitialCountValue);
}
}
private void recordRowsInError(DataRow row)
{
if (_rowErrors.ContainsKey(row.RowError))
{
_rowErrors[row.RowError]++;
return;
}
_rowErrors.Add(row.RowError, InitialCountValue);
}
private void appendSummaryIntro(StringBuilder sb)
{
sb.AppendFormat("Errors reported for {1} [{2}]{0}", Environment.NewLine, ErroredTable.GetType().FullName, ErroredTable.TableName);
}
private void appendErroredColumns(StringBuilder sb)
{
sb.AppendFormat("Columns in error: [{1}]{0}", Environment.NewLine, _erroredColumns.Count);
foreach (string columnName in _erroredColumns.Keys)
{
sb.AppendFormat("\t[{1}] - rows affected: {2}{0}",
Environment.NewLine,
columnName,
_erroredColumns[columnName]);
}
}
private void appendRowErrors(StringBuilder sb)
{
sb.AppendFormat("Row errors: [{1}]{0}", Environment.NewLine, _rowErrors.Count);
foreach (string rowError in _rowErrors.Keys)
{
sb.AppendFormat("\t[{1}] - rows affected: {2}{0}",
Environment.NewLine,
rowError,
_rowErrors[rowError]);
}
}
/// <summary>
/// Get the DataTable in error
/// </summary>
public DataTable ErroredTable
{
get { return _erroredTable; }
private set { _erroredTable = value; }
}
/// <summary>
/// Get the original ConstraintException message with extra error information
/// </summary>
public override string Message
{
get { return base.Message + Environment.NewLine + buildErrorSummaryMessage(); }
}
private readonly SortedDictionary<string, int> _rowErrors = new SortedDictionary<string, int>();
private readonly SortedDictionary<string, int> _erroredColumns = new SortedDictionary<string, int>();
private DataTable _erroredTable;
}
}
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