IDbCommand PrepareCommand(string cmdText, DbParam[] parameters, CommandType cmdType, out List <OutputParameter> outputParameters)
{
outputParameters = null;
IDbCommand cmd = this._dbConnection.CreateCommand();
cmd.CommandText = cmdText;
cmd.CommandType = cmdType;
cmd.CommandTimeout = this._commandTimeout;
if (this.IsInTransaction)
{
cmd.Transaction = this._dbTransaction;
}
if (parameters != null)
{
for (int i = 0; i < parameters.Length; i++)
{
DbParam param = parameters[i];
if (param == null)
{
continue;
}
if (param.ExplicitParameter != null)/* 如果存在创建好了的 IDbDataParameter，则直接用它。同时也忽视了 DbParam 的其他属性 */
{
cmd.Parameters.Add(param.ExplicitParameter);
continue;
}
IDbDataParameter parameter = cmd.CreateParameter();
parameter.ParameterName = param.Name;
Type parameterType;
if (param.Value == null || param.Value == DBNull.Value)
{
parameter.Value = DBNull.Value;
parameterType = param.Type;
}
else
{
parameterType = param.Value.GetType();
if (parameterType.IsEnum)
{
parameterType = Enum.GetUnderlyingType(parameterType);
parameter.Value = Convert.ChangeType(param.Value, parameterType);
}
else
{
parameter.Value = param.Value;
}
}
if (param.Precision != null)
{
parameter.Precision = param.Precision.Value;
}
if (param.Scale != null)
{
parameter.Scale = param.Scale.Value;
}
if (param.Size != null)
{
parameter.Size = param.Size.Value;
}
if (param.DbType != null)
{
parameter.DbType = param.DbType.Value;
}
else
{
DbType?dbType = MappingTypeSystem.GetDbType(parameterType);
if (dbType != null)
{
parameter.DbType = dbType.Value;
}
}
const int defaultSizeOfStringOutputParameter = 4000;/* 当一个 string 类型输出参数未显示指定 Size 时使用的默认大小。如果有需要更大或者该值不足以满足需求，需显示指定 DbParam.Size 值 */
OutputParameter outputParameter = null;
if (param.Direction == ParamDirection.Input)
{
parameter.Direction = ParameterDirection.Input;
}
else if (param.Direction == ParamDirection.Output)
{
parameter.Direction = ParameterDirection.Output;
param.Value = null;
if (param.Size == null && param.Type == UtilConstants.TypeOfString)
{
parameter.Size = defaultSizeOfStringOutputParameter;
}
outputParameter = new OutputParameter(param, parameter);
}
else if (param.Direction == ParamDirection.InputOutput)
{
parameter.Direction = ParameterDirection.InputOutput;
if (param.Size == null && param.Type == UtilConstants.TypeOfString)
{
parameter.Size = defaultSizeOfStringOutputParameter;
}
outputParameter = new OutputParameter(param, parameter);
}
else
{
throw new NotSupportedException(string.Format("ParamDirection '{0}' is not supported.", param.Direction));
}
cmd.Parameters.Add(parameter);
if (outputParameter != null)
{
if (outputParameters == null)
{
outputParameters = new List <OutputParameter>();
}
outputParameters.Add(outputParameter);
}
}
}
return(cmd);
}
IDbCommand PrepareCommand(string cmdText, DbParam[] parameters, CommandType cmdType)
{
IDbCommand cmd = this._dbConnection.CreateCommand();
cmd.CommandText = cmdText;
cmd.CommandType = cmdType;
cmd.CommandTimeout = this._commandTimeout;
if (this.IsInTransaction)
{
cmd.Transaction = this._dbTransaction;
}
if (parameters != null)
{
for (int i = 0; i < parameters.Length; i++)
{
DbParam param = parameters[i];
if (param == null)
{
continue;
}
if (param.ExplicitParameter != null)/* 如果存在创建好了的 IDbDataParameter，则直接用它。同时也忽视了 DbParam 的其他属性 */
{
cmd.Parameters.Add(param.ExplicitParameter);
continue;
}
IDbDataParameter parameter = cmd.CreateParameter();
parameter.ParameterName = param.Name;
Type parameterType;
if (param.Value == null || param.Value == DBNull.Value)
{
parameter.Value = DBNull.Value;
parameterType = param.Type;
}
else
{
parameter.Value = param.Value;
parameterType = param.Value.GetType();
}
if (param.Precision != null)
{
parameter.Precision = param.Precision.Value;
}
if (param.Scale != null)
{
parameter.Scale = param.Scale.Value;
}
if (param.Size != null)
{
parameter.Size = param.Size.Value;
}
if (param.DbType != null)
{
parameter.DbType = param.DbType.Value;
}
else
{
DbType?dbType = MappingTypeSystem.GetDbType(parameterType);
if (dbType != null)
{
parameter.DbType = dbType.Value;
}
}
cmd.Parameters.Add(parameter);
}
}
return(cmd);
}