public static string FormatMessage(DbException ex, SqlMigrationRun sqlRun)
{
string errorMsg = string.Empty;
if (ex is SqlException)
{
var sqlEx = ex as SqlException;
var no = sqlEx.Number;
switch (no)
{
case 515:
errorMsg = "把一个可空字段变更为非空字段时，由于存在不可空约束，所以数据库该表中不能有该字段为空的数据行。\r\n";
break;
case 547:
errorMsg = "把一个字段变更为非空外键字段时，由于外键约束，所以数据库该表中不能有该字段数据不满足引用约束的数据行。\r\n";
break;
default:
break;
}
}
errorMsg += ex.Message;
var error = "执行数据库迁移时出错：" + errorMsg;
if (sqlRun != null)
{
error += Environment.NewLine + "对应的 SQL：" + sqlRun.Sql;
}
return(error);
}
public static string FormatMessage(DbException ex, SqlMigrationRun sqlRun)
{
string errorMsg = string.Empty;
if (ex is SqlException)
{
var sqlEx = ex as SqlException;
var no = sqlEx.Number;
switch (no)
{
case 515:
errorMsg = "把一个可空字段变更为非空字段时，由于存在不可空约束，所以数据库该表中不能有该字段为空的数据行。\r\n";
break;
case 547:
errorMsg = "把一个字段变更为非空外键字段时，由于外键约束，所以数据库该表中不能有该字段数据不满足引用约束的数据行。\r\n";
break;
default:
break;
}
}
errorMsg += ex.Message;
var error = "执行数据库迁移时出错：" + errorMsg;
if (sqlRun != null)
{
error += Environment.NewLine + "对应的 SQL：" + sqlRun.Sql;
}
return error;
}
private void RunMigration(DbMigration migration, bool up)
{
var runList = this.GenerateRunList(migration, up);
if (runList.Count == 0) return;
this.ExecuteWithoutDebug(() =>
{
var dba = this.DBA;
if (runList.Count > 1)
{
/*********************** 代码块解释 *********************************
*
* 如果执行多句 SQL，则需要主动打开连接，
* 否则 DBA 可能会打开之后再把连接关闭，造成多次打开连接，引起分布式事务。
* 而分布式事务在一些数据库中并不支持，例如 SQLCE。
*
**********************************************************************/
bool opend = false;
var con = dba.Connection;
try
{
if (con.State != ConnectionState.Open)
{
con.Open();
opend = true;
}
using (var tran = new TransactionScope())
{
foreach (var item in runList)
{
this._currentRun = item as SqlMigrationRun;
item.Run(dba);
}
tran.Complete();
}
}
finally
{
if (opend)
{
con.Close();
}
}
}
else
{
var singleRun = runList[0];
this._currentRun = singleRun as SqlMigrationRun;
singleRun.Run(dba);
}
});
}