本文整理汇总了C#中System.Data.Common.DbCommand.ExecuteScalar方法的典型用法代码示例。如果您正苦于以下问题：C# DbCommand.ExecuteScalar方法的具体用法？C# DbCommand.ExecuteScalar怎么用？C# DbCommand.ExecuteScalar使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类System.Data.Common.DbCommand的用法示例。
在下文中一共展示了DbCommand.ExecuteScalar方法的15个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C#代码示例。
示例1: ExecuteWithChanges
public object ExecuteWithChanges(DbCommand cmd, ChangeInfo changeInfo)
{
object result;
using (var conn = DB.OpenConnection())
using (var tx = conn.BeginTransaction())
{
try
{
cmd.Connection = conn;
cmd.Transaction = tx;
result = cmd.ExecuteScalar();
if (AdminInitialise.IsChangesEnabled)
{
var changeCmd = CreateChangeCommand(changeInfo, result.ToString());
changeCmd.Connection = conn;
changeCmd.Transaction = tx;
changeCmd.ExecuteNonQuery();
}
tx.Commit();
}
catch (Exception ex)
{
result = null;
_notificator.Error(ex.Message);
tx.Rollback();
}
}
return result;
}示例2: ExecuteScalar
// execute a select command, return single result as a string
public static string ExecuteScalar(DbCommand command)
{
string result = "";
command.Connection.Open();
result = command.ExecuteScalar().ToString();
return result;
}示例3: ExecuteInsert
public override LastInsertId ExecuteInsert(DbCommand cmd, string idKey)
{
cmd.Execute();
cmd.Reset();
cmd.CommandText = "select @@IDENTITY as id";
var rez = cmd.ExecuteScalar();
return new LastInsertId(rez);
}示例4: ExecuteInsert
public override LastInsertId ExecuteInsert(DbCommand cmd, string idKey)
{
if (!string.IsNullOrEmpty(idKey))
{
cmd.CommandText += (" returning " + EscapeName(idKey));
}
return new LastInsertId(cmd.ExecuteScalar());
}示例5: ExecuteScalar
public static int ExecuteScalar(DbCommand comm)
{
comm.Connection.Open();
int i = Convert.ToInt32(comm.ExecuteScalar());
comm.Connection.Close();
return i;
}示例6: GetTheCurrentVersionFromTheDatabase
private static long GetTheCurrentVersionFromTheDatabase(DbCommand cmd, string sqlStatement)
{
long currentVersion;
cmd.CommandText = sqlStatement;
var version = cmd.ExecuteScalar<string>();
if (version != null)
version = version.Trim();
long.TryParse(version, out currentVersion);
return currentVersion;
}示例7: ExecScalar
public object ExecScalar(DbCommand cm)
{
//OnExecuting(ExecTypes.Scalar, cm);
object r = cm.ExecuteScalar();
//OnExecuted(ExecTypes.Scalar, cm, r);
return r;
}示例8: ExecuteInsert
public override LastInsertId ExecuteInsert(DbCommand cmd, string idKey)
{
if (idKey != null)
{
cmd.CommandText += ";SELECT last_insert_rowid()";
var rez = cmd.ExecuteScalar();
return new LastInsertId(rez);
}
cmd.Execute();
return LastInsertId.Empty;
}示例9: ExecuteResultInternal
protected override object ExecuteResultInternal(IDbExecuteContext ctx, DbCommand command, Type resultType, object resultInstance)
{
var type = this.GetResultType(ctx, resultType, resultInstance, null);
if(type != null && !(type.IsValueType || type == typeof(string))) {
throw new DataException("要求返回的类型不正确");
}
var result = command.ExecuteScalar();
if(!Convert.IsDBNull(result) && result != null && type != null) {
var ut = Nullable.GetUnderlyingType(type) ?? type;
result = Convert.ChangeType(result, ut);
}
return Convert.IsDBNull(result) ? null : result;
}示例10: ExecuteWithChanges
public object ExecuteWithChanges(
DbCommand cmd,
EntityRecord entityRecord,
EntityChangeType changeType,
Func<string> changeDescriber = null)
{
_log.DebugFormat("Executing command: \r\n {0}", cmd.CommandText);
object result;
using (var conn = DB.OpenConnection(_admin.ConnectionStringName))
using (var tx = conn.BeginTransaction())
{
try
{
cmd.Connection = conn;
cmd.Transaction = tx;
result = cmd.ExecuteScalar();
if (result != null)
{
if (_admin.IsChangesEnabled)
{
var changeCmd = CreateChangeCommand(entityRecord, changeType, result.ToString(), changeDescriber);
_log.DebugFormat("Executing change command: \r\n {0}", changeCmd.CommandText);
changeCmd.Connection = conn;
changeCmd.Transaction = tx;
changeCmd.ExecuteNonQuery();
}
_log.Debug("Commit transaction");
tx.Commit();
}
else
{
Rollback(tx);
}
}
catch (Exception ex)
{
_log.Error(ex);
Rollback(tx);
throw;
}
}
return result;
}示例11: ExecuteScalarCommand
public static void ExecuteScalarCommand(DbCommand command)
{
try
{
command.Connection.Open();
command.ExecuteScalar();
}
catch (Exception ex)
{
Utilities.LogError(ex);
throw;
}
finally
{
command.Connection.Close();
}
}示例12: ExcuteScalar
public static string ExcuteScalar(DbCommand cmd)
{
string value = "";
try
{
cmd.Connection.Open();
value = cmd.ExecuteScalar().ToString();
}
catch (Exception ex)
{
Utilities.LogError(ex);
throw;
}
finally { cmd.Connection.Close(); }
return value;
}示例13: ExecuteInsertAndReturnId
public int ExecuteInsertAndReturnId(DbCommand command)
{
DbConnection connection = null;
try
{
connection = CreateOpenConnection();
command.Connection = connection;
command.ExecuteNonQuery();
command.Parameters.Clear();
command.CommandText = "SELECT @@IDENTITY";
return Convert.ToInt32(command.ExecuteScalar());
//return
}
finally // is executed in case of exceptions as well
{
ReleaseConnection(connection);
}
}示例14: ExecuteScalar
public static string ExecuteScalar(DbCommand comm)
{
string retrievedRows = "";
try
{
comm.Connection.Open();
retrievedRows = comm.ExecuteScalar().ToString();
}
catch (Exception ex)
{
throw;
}
finally
{
comm.Connection.Close();
}
return retrievedRows;
}示例15: ExecuteScalar
// execute a select command and return a single result as a string
public static string ExecuteScalar(DbCommand command)
{
string value = "";
try
{
command.Connection.Open();
value = command.ExecuteScalar().ToString();
}
catch (Exception ex)
{
throw ex;
}
finally
{
command.Connection.Close();
}
return value;
}